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Downloaded Fr Advances in strength theories for materials under complex stress state in the 20th Century Mao-hong Yu School of Civil Engineering & Mechanics, Xi’an Jiaotong University, Xi’an, 710049, China mhyu@xjtu.edu.cn; isstad@xjtu.edu.cn It is 100 years since the well-known Mohr-Coulomb strength theory was established in 1900. A considerable amount of theoretical and experimental research on strength theory of materi- als under complex stress state was done in the 20th Century. This review article presents a survey of the advances in strength theory~yield criteria, failure criterion, etc! of materials~in- cluding metallic materials, rock, soil, concrete, ice, iron, polymers, energetic material, etc! under complex stress, discusses the relationship among various criteria, and gives a method of choosing a reasonable failure criterion for applications in research and engineering. Three se- ries of strength theories, the unified yield criterion, the unified strength theory, and others are summarized. This review article contains 1163 references regarding the strength theories. This review also includes a brief discussion of the computational implementation of the strength theories and multi-axial fatigue.@DOI: 10.1115/1.1472455# a a n u t a v u e m L o i g e re and s in n s cs, nd ys r ner 1 INTRODUCTION Strength theory deals with the yield and failure of materi under a complex stress state. Strength theory is a gen term. It includes yield criteria and failure criteria, as well multiaxial fatigue criteria, multiaxial creep conditions, a material models in computational mechanics and comp codes. It is an important foundation for research on strength of materials and structures. Strength theory widely used in physics, mechanics, material science, e science, and engineering. It is of great significance in th retical research and engineering application, and is also important for the effective utilization of materials. Partic larly for design purposes, it is important that a reliab strength prediction be available for various combinations multiaxial stresses. It is an interdisciplinary field where t physicist, material scientist, earth scientist, and mechan and civil engineers interact in a closed loop. Strength theory is a very unusual and wonderful subj The objective is very simple, but the problem is very co plex. It is one of the earliest objectives considered by onardo da Vinci~1452-1519!, Galileo Galilei ~1564-1642!, Coulomb~1736-1806!, and Otto Mohr~1835-1918!, but it is still an open subject. Considerable efforts have been dev to the formulation of strength theories and to their correlat with test data, but no single model or criterion has emer which is fully adequate. Hundreds of models or criteria ha been proposed. It seems as if an old Chinese said: ‘‘L hundred flowers bloom and a hundred schools of thou contend.’’ Timoshenko ~1878-1972! was an outstanding scientis distinguished engineer, and a great and inspiring profes Transmitted by Associate Editor F Ziegler ASME Reprint No AMR325 $34.00 Appl Mech Rev vol 55, no 3, May 2002 16 om: http://appliedmechanicsreviews.asmedigitalcollection.asme.org/ on 05/10/ ls eral s d ter he is rth eo- ery - le of he ical ct. - e- ted on ed ve t a ght t, sor. Timoshenko’s summers of the years from 1903 to 1906 we spent in Germany where he studied under Foppl, Prandtl, Klein. After his return from Germany in 1904, he wrote hi first paper on the subject of ‘‘various strength theories’’ 1904@1#. ‘‘Strength theories’’ was also the title of sections i two of his books@2,3#. Now, ‘‘strength theories’’ is a chapter of most courses of ‘‘Mechanics of Materials,’’ sometime referred to as ‘‘Strength of Materials.’’ Moreover, ‘‘yield cri- teria’’ or ‘‘failure criteria’’ is a chapter of most courses in Plasticity, Geomechanics, Soil Mechanics, Rock Mechani and Plasticity of Geomaterials, etc. This subject, although there are some review articles a books, is difficult and heavy to survey. Some of the surve were contributed by Mohr@4#, Westergaard@5#, Schleicher @6#, Nadai @7,8#, Marin @9#, Gensamer@10#, Meldahl @11#, Dorn @12#, and Prager@13# in the first half of the 20th cen- tury. It was also reviewed by Freudental and Geiringer@14#, Naghdi @15#, Filonenko-Boroditch@16#, Marin @17#, Paul @18#, Goldenblat and Kopnov@19#, and Taira~creep under multiaxial stress! @20# in the 1960s. This subject was furthe reviewed by Tsai and EM Wu~anisotropic material! @21#, Bell ~experiments! @22#, Krempl @23#, EM Wu ~anisotropic failure criteria! @24#, Michino and Findley~metals! @25#, Sa- lencon~soil! @26#, Genievet al ~concrete! @27# in the 1970s; and by Yu @28,29#, Zyczkowcki @30#, WF Chen~concrete! @31#, Ward~polymer! @32#, WF Chen and Baladi~soils! @33#, Hamza~ice! @34#, Shaw@35#, Hosford@36#, Rowlands@37#, Ikegami~low temperature! @38#, and Desai@39# in the 1980s. Strength theories were subsequently reviewed by Klaus @40#, WF Chen@41,42#, Du @43#, Jiang~concrete! @44#, An- dreev~rock! @45#, Shen~rock, soil! @46#, Kerr ~ice! @47#, Gao and Brown~Multiaxial fatigue! @48#, You and SB Lee~Mul- © 2002 American Society of Mechanical Engineers9 2013 Terms of Use: http://asme.org/terms o . h n i o g a s i d t era- the ci- wo al ld ree e, ow al to w. by ri- his - es d be icity otal rts: 2 ent g - to I any in g ry. eas in they om- sign th m m- ch- as tut- 170 Yu: Advances in strength theories Appl Mech Rev vol 55, no 3, May 2002 Downl tiaxial fatigue! @49#, Sheorey~rock! @50#, WF Chen ~con- crete! @51#, Yu, Zhao, and Guan~rock, concrete! @52#, Shen and Yu@53#, and Munx and Fett~ceramics! @54# in the 1990s. Two books regarding strength theory are published@55,56#. The advances in strength theories of materials under c plex stress state in the 20th century will be summarized the framework of continuum and engineering application 2 STRENGTH THEORIES BEFORE THE 20th CENTURY 2.1 Early work Leonardo da Vinci~1452-1519! and Galileo Galilei~1564- 1642! were among the most outstanding scientists of t period. They may be the earliest researchers of the stre of materials and structures. Da Vinci and Galileo did tens tests of wire and stone, as well as bending tests. Da V believed that the strength of an iron wire would depend s nificantly on its length. Galilei believed that fracture occu when a critical stress was reached@2#. Coulomb ~1736-1806! may be the first researcher in th maximum shear stress strength theory. No other scientis the eighteenth century contributed as much as Coulomb to the science of mechanics of elastic bodies@2#. Coulomb’s Memoir Essay@57# was read by him to the Academy o France on March 10 and April 2, 1773, and published Paris in 1776. The paper began with a discussion of exp ments which Coulomb made for the purpose of establish the strength of some kind of sandstone; then, Coulomb g a theoretical discussion of the bending of beams, the c pression of a prism, and the stability of retaining walls a arches. Coulomb assumed that fracture is due to sliding alon certain plane, and that it occurs when the component of fo along this plane becomes larger than the cohesive resist in shear along the same plane. To bring the theory into be agreement with experimental results, Coulomb propo that, not only should cohesive resistance along the sh plane be considered, but also friction caused by the nor force acting on the same plane. This was the first descrip of the famous Mohr-Coulomb Strength Theory. 2.2 Strength theories in the 19th century There were three strength theories in the 19th century. The maximum stress theory was the first theory relating the strength of materials under complex stress. It consid the maximum or minimum principal stress as the criter for strength. This criterion was assumed by such scientist Lamé ~1795-1870! and Rankine~1820-1872!, and was ex- tended with the well known textbook of Rankine’s,Manual of Applied Mechanics@58#, the first edition of which ap- peared in 1858 at Glasgow University,and was publishe 1861, the 21st edition entitledApplied Mechanicsbeing pub- lished in 1921. Only one principal stresss1 of the 3D stressess1 ,s2 ,s3 was taken into account. The second strength theory was the maximum str theory. Mariotte~1620-1684! made the first statement on th maximum elongation criterion or maximum strain criterio @59#. Sometimes, it was called Saint-Venant’s criterion or oaded From: http://appliedmechanicsreviews.asmedigitalcollection.asme.org m- in at gth ile nci ig- rs e t of did f in eri- ing ave m- nd a rce nce tter ed ear mal tion to ers on s as in ain e n he second Strength Theory in the Russian and Chinese lit ture, and the maximum normal stress criterion was called First Strength Theory. Maximum strain theory was generally accepted, prin pally under the influence of such authorities as the t French academicians Poncelet~1788-1867! and Saint-Venant ~1797-1886! @60#. In this theory it is assumed that a materi begins to fail when the maximum strain equals the yie point strain in simple tension. This theory does not ag well with most experiments. It was very popular at one tim but no one uses it today. In 1864, Tresca presented two notes dealing with the fl of metals under great pressure to the French Academy@61#. He assumed that the maximum shear stress at flow is equ a specific constant. It is called the Tresca yield criterion no A maximum shear stress criterion was also proposed Guest@62#. This theory gives better agreement with expe ment for some ductile materials and is simple to apply. T theory takes two principal stressess1 and s3 of the 3D stressess1 , s2 , s3 into account, and the intermediate prin cipal stresss2 is not taken into account. Beltrami suggested that, in determining the critical valu of combined stresses, the amount of strain energy shoul adopted as the criterion of failure@63#. This theory does not agree with experiments and has not been used in plast and engineering. In 1856, Maxwell suggested that the t strain energy per unit volume can be resolved into two pa 1! the strain energy of uniform tension or compression and! the strain energy of distortion. Maxwell made the statem in his letter to William Thomson as follows: ‘‘I have stron reasons for believing that when~the strain energy of distor tion! reaches a certain limit then the element will begin give way.’’ Further on he stated: ‘‘This is the first time that have put pen to paper on this subject. I have never seen investigation of this question. Given the mechanical strain three directions on an element, when will it give way?’’@2#. At that time, Maxwell already had the theory of yieldin which we now call the maximum distortion energy theo But he never came back again to this question, and his id became known only after publication of Maxwell’s letter the 1930s. It took researchers considerable time before finally developed@2# the theory identical with that of Max- well. Strength theory was studied by Foppl@64#, Voigt @65#, Mohr, Guest, and others at the end of the 19th century. C parisons of strength theories as applied to various de problems were given in a paper by Marin@9# and a book by Nadai @66#. A comprehensive bibliography on streng theory before the 1930s can be found in the article by From @67#. A discussion of various strength theories with a co plete bibliography of the subject was given by Ros and Ei inger @68#. 3 THREE SERIES OF STRENGTH THEORIES Mohr used the stress circle method@69# in developing his theory of strength in 1900@70#. Otto Mohr ~1835-1918! was a very good professor. When thirty-two years old, he w already a well-known engineer and was invited by the S / on 05/10/2013 Terms of Use: http://asme.org/terms w g f s n o r w i c s h c h f r o ing dro- uld ed sion nd s. It pace e f geo- ous by in s of was up ed - dtl al ure m- nd was wn at ted the m. ield . to of the- st- is to th sses hear Appl Mech Rev vol 55, no 3, May 2002 Yu: Advances in strength theories 171 Downloaded From tgart Polytechnicum Institute~Stuttgart University! to be- come the professor of engineering mechanics. His lectu aroused great interest in his students, some of whom w themselves outstanding, such as Bach and Foppl. Foppl stated that all the students agreed that Mohr their finest teacher@2#. Mohr always tried to bring somethin fresh and interesting to the students’ attention. The reason his students’ interest in his lectures stemmed from the that he not only knew the subject thoroughly, but also h himself done much in the creation of the science which presented. Mohr made a more complete study of the strength of m terials. He considered failure in broad senses; that is, it be yielding of the material or fracture. Mohr’s criterion ma be considered as a generalized version of the Tresca crite @61#. Both criteria were based on the assumption that maximum shear stress is the only decisive measure of pending failure. However, while the Tresca criterion assum that the critical value of the shear stress is a constant, Mo failure criterion considered the limiting shear stress in plane to be a function of the normal stress in the same tion at an element point. Mohr considered only the largest stress circle. He calle the principal circle and suggested that such circles should constructed when experimenting for each stress conditio which failure occurs. The strength of materials under a co plex stress state can be determined by the corresponding iting principal circle. At that time, most engineers working in stress analy followed Saint-Venant and used the maximum strain the as their criterion of failure. A number of tests were ma with combined stresses with a view to checking Moh theory@65,71,72#. All these tests were made with brittle ma terials and the results obtained were not in agreement Mohr’s theory. Voigt came to the conclusion that the quest of strength is too complicated, and that it is impossible devise a single theory for successful application to all kin of structural materials@2#. The idea of Mohr’s failure criterion may be tracked ba to Coulomb~1773! @67#. This criterion is now referred to a the Mohr-Coulomb strength theory~failure criterion!. In the special case of metallic materials with the same strengt tension and in compression, the Mohr-Coulomb stren theory is reduced to the maximum-shear stress criterion Tresca@61#. When Otto Mohr was teaching at the Stuttgart Polyte nicum, his lectures caused August Foppl to devote mos his energy to study of the theory of structures. Like Mo Foppl’s activity in both research and teaching at the Po technical Institute of Munich was remarkably successful. was an outstanding professor and knew how to hold stude interest, although his classes were very large. At that time, Foppl followed Saint-Venant’s notion an used the maximum strain theory in deriving formulas calculating safe dimensions of structures. But at the sa time he was interested in the various other strength theo and to clarify the question of which should be used, he c ducted some interesting experiments. By using a thi : http://appliedmechanicsreviews.asmedigitalcollection.asme.org/ on 05/10/2 res ere as for act ad he a- can y rion the im- ed hr’s a ec- d it be in m- lim- sis ry de ’s - ith on to ds k in gth of h- t of r, ly- He nts’ d or me ies, n- ck- walled cylinder of high-grade steel, he succeeded in mak compressive tests of various materials under great hy static pressures. He found that an isotropic material co withstand very high pressure in that condition. He design and constructed a special device for producing compres of a cubic specimen in two perpendicular directions a made a series of tests of this kind with cement specimen is the earliest high-pressure test. Haigh @73# and Westgaard@5# introduced the limit surface in a 3D principal stress space. The advantage of such s lies in its simplicity and visual presentation. It is called th Haigh-Wesagaard space or stress space. Photographs o metric models ofsuch surfaces corresponding to vari yield criteria before 1944 can be found in the papers Burzynski @74# and Meldahl@11#. The yield surface in the stress space can be transformed into the strain space@75– 77#. A comparison of various strength theories applied machine design before the 1930s was given by Marin@78#. Prandtl was a great scientist. He was in the Academic the USA, France, and other countries. Strength theory one of the subjects studied by him. Prandtl himself drew his theory of the two types of fracture of solids and devis his model for slip@2#. At that time, Prandtl’s graduate stu dents worked mainly on strength of materials until Pran went to the USA in 1941. Von Karman did experiment work on the strength of stone under confining lateral press at Goettingen University, and did much work in aerodyna ics in the USA; Nadai did important work on strength a plasticity at the Westinghouse Research Lab; Prager leading the new research in strength and plasticity at Bro University, and several well-known professors worked Brown University with Prager@79,80#; Flügge and Timosh- enko worked at Stanford University. A lot of strength theories and expressions were presen after Mohr. The proposed criteria and material models in 20th century are too many, and it is difficult to classify the Fortunately, a fundamental postulate concerning the y surfaces was introduced by Drucker@81,82# and Bishop and Hill @83# with the convexity of yield surface determined After that the convexity of yield surface was generalized the strain space by Il’yushin in 1961. Since then the study strength theory has been developing on a more reliable oretical basis. The convex region and its two bounds are most intere ing. One method we used for representing these theories use the principal shear stressest13, t12, t23 and the normal stresss13, s12, s23 acting on the same planes. Streng theories may be divided into three kinds~Fig. 1 and Table 1!. Three principal shear stresses and relating normal stre are t i j 5 1 2 ~s i2s j !; s i j 5 1 2 ~s i1s j !; i , j 51,2,3 3.1 Single-shear strength theory„SSS theory… This series of strength theories considers the maximum s stresst13 and the influence of the normal stresss13 acting on the same section. It can be written mathematically as F~t13,s13!5C (1) 013 Terms of Use: http://asme.org/terms al 172 Yu: Advances in strength theories Appl Mech Rev vol 55, no 3, May 2002 Downl Table 1. Summary of three series of strength theories SSS series ~Single shear stress series of strength theory! OSS series ~Octahedral shear stress series of strength theory! TSS series ~Twin shear stress series of strength theories! Model of element Hexahedron Isoclinal octahedron Dodecahedron or orthogon octahedron Shear stress yield criterion SSS yield criterion OSS yield criterion TSS yield criterion t135C, Tresca, 1864; Guest, 1900 t85C, von Mises 1913; Eichinger 1926; Nadai 1937 t131t12(or t23)5C, Hill, 1950; Yu, 1961; Haythornthwaite, 1961 Shear strain yield criterion SSS~Strain! yield criterion g135C OSS~Strain! yield criteriong85C TSS ~Strain! yield criterion. g131g12(or g23)5C Failure criterion SSS failure criterion t131bs135C OSS failure criteriont81bs85C TSS failure criterion t131t12(or t23)1bs13 1bs12(or s23)5C Coulomb, 1773 Burzynski, 1928 Mohr, 1882-1900 Drucker-Prager, 1952 Yu-He-Song, 1985 Slip condition SSS Slip condition OSS Slip condition TSS Slip condition Schmid, 1924 von Mises, 1926 Yu-He, 1983 Cap model SSS Cap model OSS Cap model TSS Cap model Roscoe1963; Wei,1964 Baladi, Roscoe, Mroz Yu-Li, 1986 Smooth ridge model SSS ridge model OSS ridge model TSS ridge model Argyris-Gudehus, 1973; Lade-Duncan, 1975 Yu-Liu, 1988 Matsuoka-Nakai,1974 Multi-parameter criterion Ashtonet al ~1965! Hobbs~1964! Murrell ~1965! Franklin ~1971! Hoek-Brown~1980! Pramono-Willam~1989! Bresler-Pister~1958!; Willam-Warnke~1974!; Ottosen~1977!; Hsieh-Ting-Chen~1979! Podgorski~1985!; Desai, de Boer~1988!; Song-Zhao~1994!; Ehlers~1995! TSS Multi-parameter criterion Yu-Liu, 1988 ~1990! h y x- sion ) d According to the shear stress, it may be referred to as single-shear strength theory~SSS theory!. 3.1.1 Single-shear yield criterion [61] The expression is f 5t135C, or f 5s12s35ss (2) It is the one-parameter criterion of the SSS~single-shear strength! theory. This yield criterion is also referred to as t maximum shear stress criterion or the third strength theor Russian and in Chinese. It is adopted only for one kind material with the same yield stress both in tension and compressions t5sc5ss . The generalization of the Tresca criterion by adding hydrostatic stress termsm was given by Sandel@30#, Davi- ing. r- m- ined ub- e h a is e de- oaded From: http://appliedmechanicsreviews.asmedigitalcollection.asme.org the e in of in a genkov @84#, Drucker @85#, Volkov @86#, and Hara@87,88# and others. The limit surface is a pyramid with regular he agonal cross section similar to the Tresca’s. The expres of the extended Tresca criterion is f 5t131bsm5C (3) 3.1.2 Single-shear strength theory (Mohr-Coulomb 1900 The expression is F5t131bs135C, or F5s12as35s t , a5s t /sc (4) It is a two-parameter criterion of the SSS~single-shear strength! theory. It is the famous Mohr-Coulomb theory an is also the most widely used strength theory in engineer The failure locus of SSS theory on thep plane ~deviatoric plane! has the inner hexagonal threefold symmetry~lower bound! as shown in Fig. 1. It is interesting that Shield@89# was the first to publish the correct form of the Moh Coulomb limit locus in the deviatoric plane in 1955@18#. It is also indicated by Shield that after the paper was co pleted, he learned that the correct yield surface was obta previously by Professor Prager and Dr Bishop in an unp lished work @89#. Before Shield, the limit surface of th Mohr-Coulomb strength theory was always consistent wit sixfold symmetry hexagonal pyramid failure surface that intercepted by a Tresca-type hexagonal cylinder. Single-shear strength theory~Mohr-Coulomb 1900! forms the lower ~inner! bound for all the possible convex failur surfaces coincided with the Drucker postulation on the Fig. 1 Limiting loci of SSS, OSS, and TSS theories / on 05/10/2013 Terms of Use: http://asme.org/terms t . h h h e o e o n ock hear ati- s: ls es- d n- ean - by ex- r n ker- a von to as Appl Mech Rev vol 55, no 3, May 2002 Yu: Advances in strength theories 173 Downloaded From viatoric plane in stress space. No admissible limit surfa may exceed the Mohr-Coulomb limit surface from below, shown in Fig. 1. The disadvantage of the Mohr-Coulomb theory is that intermediate principal stresss2 is not taken into account Substantial departures from the prediction of the Mo Coulomb theory were observed by many researchers,eg, Shibat and Karuhe@91#, Mogi @92,93#, Ko and Scott@94#, Green and Bishop@95#, Vaid and Campanella@96#, Lade and Musante@97#, Michelis @98,99# and others. 3.1.3 Multi-parameter Single-Shear criteria Multi-parameter Single-Shear criteria are nonlinear Mo Coulomb criteria~Mogi @92#, Salencon@26#, Hoek-Brown @100#, et al! used in rock mechanics and rock engineering Some forms are expressed as follows F5t131ls13 n 50 Murrell @101# (5) F5S s12s32c D n 512 s11s3 2t Ashton et al @102# (6) F5~s12s3!1Ams12c50 Hoek-Brown @100# (7) F5F ~12k! s12sc2 1 s12s3sc G 2 1k2m s1 sc 5k2c Pramono-Willam @103,104# (8) in which kP(0,1) is the normalized strength parameter,c andm are the cohesive and frictional parameters. 3.1.4 Single-shear cap model It is used in soil mechanics and engineering. It will be d cussed in the next section. 3.1.5 Application of the SSS theory Single-shear yield criterion~Tresca yield criterion! has been widely used for metallic materials and in mechanical en neering. Mohr’s theory ~Single-shear strength theory! attracted great attention from engineers and physicists. ‘‘The Mo Coulomb failure criterion is currently the most widely us in soil mechanics’’~Bishop@105#!. ‘‘The Mohr-Coulomb theory is currently the most widely used for soil in practic applications owing to its extreme simplicity’’@41,106#. ‘‘In soil mechanics, the Coulomb criterion is widely used; and applied mechanics, Mohr’s criterion has been widely us for concrete Mohr-Coulomb criterion appears to be m popular.’’ ‘‘Taking into account its extreme simplicity, th Mohr-Coulomb criterion with tension cutoffs is in man cases a fair first approximation and therefore suitable manual calculation. However, the failure mechanism ass ated with this model is not verified in general by the te results, and the influence of the intermediate principal str is not taken into account,’’ as indicated by Chen@31#. SSS theory is the earliest and simplest series of stre theory. A considerable amount of research was done in c nection with it. However, it is still studied up to the prese ~Shield @89#; Paul @18,107#; Harkness@108#; Pankaj-Moin : http://appliedmechanicsreviews.asmedigitalcollection.asme.org/ on 05/10/2 ce as he r- r- . is- gi- r- d al in ed; st y for ci- st ess gth on- nt @109,110#; Heyman @111#; Schajer@112#!. Multi-parameter Single-Shear criteria were used in rock mechanics and r engineering. 3.2 Octahedral-shear strength theory„OSS Theory… This series of strength theories considers the octahedral s stresst8 and the influence of the octahedral normal stresss8 acting upon the same section. It can be written mathem cally as F~t8 ,s8!5C or t85 f ~s8! (9) This is a fruitful series in the strength theory. It contain 3.2.1 Octahedral-shear stress yield criterion (von Mises yield criterion) It is a one-parameter criterion of the OSS theory f 5t85C, or J25C, or tm5C (10) It is the widely used yield criterion for metallic materia with the same yield stress both in tension and in compr sion. It is also referred to as the von Mises criterion@113#, or octahedral shear stresst8 yield criterion by Ros and Eich- inger @68# as well as Nadai@7,8#. Sometimes, it was referre to as theJ2 theory~second invariant of deviatoric stress te sor!, shear strain energy theory~energy of distortion, Max- well @2#, Huber @114#, Hencky @115#!, equivalent stress cri- terion ~effect stress or equivalent stressse!, or mean root square shear stress theory. It was also referred as the m square shear stresstm averaged over all planes by No vozhilov @116#, mean square of principal stress deviations Paul @18#, tri-shear yield criterion by Shen@46#, and the fourth strength theory in Russian, Chinese, etc. All the pressions mentioned above are the same, because of t85 A15 3 tm5 & 3 se5A23 J25 2 3 At122 1t232 1t132 5 1 3 A~s12s2!21~s22s3!21~s32s1!2 (11) 3.2.2 Octahedral-shear failure criterion (Drucker-Prage criterion etc) It is the two-parameter criterion of the OSS~Octahedral- shear strength! theory as follows F5t81bs85C. (12) This criterion is an extension of the von Mises criterio for pressure-dependent materials, and called the Druc Prager criterion expressed by Drucker and Prager@117# as a modification of the von Mises yield criterion by adding hydrostatic stress termsm ~or s8!. The Drucker-Prager cri- terion was used widely in soil mechanics. The extended Mises criterion, however, gives a very poor approximation the real failure conditions for rock, soil, and concrete. It w indicated by Humpheson-Naylor@118#, Zienkiewicz-Pande @119#, and WF Chen@31,41,42# et al. 013 Terms of Use: http://asme.org/terms r y o e f 174 Yu: Advances in strength theories Appl Mech Rev vol 55, no 3, May 2002 Downl 3.2.3 Multi-parameter octahedral shear failure criterion The first effective formulation of such a condition in gene form was given by Burzynski@74#. The general function of a three-parameter criterion is expressed as follows F5At8 21B s8 21Cs82150 or F5t81bs81as8 25C. (13) The general equation~13! and its alternations, or particu lar cases, were later proposed, more or less independentl many authors. The formulations of more than 30 papers w similar as indicated by Zyczkowski@30#. OSS theory contains many smooth~ridge! models and three, four, and five-parameter failure criteria used in c crete mechanics. Many empirical formulas, typically fitt with different functions, were proposed around the 1980s cater to the various engineering materials. Among those w the ridge models and many multi-parametric criteria as lows: F5t81g~u!S C1 1 ) s8 t8 D 50 William et al @120# (14) F5 I 1I 2 I 3 5C Matsuoka-Nakai@121# (15) F5 I 1 3 I 3 5C Lade-Duncan@122# (16) F5 3 2 t8 21 1 3 As85C Chen-Chen@31# (17) F5 3 2 t8 22 1 6 s8 21 1 3 As85C Chen-Chen@31# (18) F5t8t1a1s81a2s8 25C1 ~u560°! F85t8c1b1s81b2s8 25C2 ~u50°! Willam-Warnke @120# (19) F5t81at8 21bs85C Ottosen @123# (20) F5S I 13I 3 227D S I 1paD m 5C Lade @124# (21) F5t81a 2t8 21bt81ds15C Hsieh et al @31# (22) F5t81a~s81b! n5C Kotsovos @125# (23) F5asm 2 1bsm1g1~t8 /g~u!! 250 Zienkiewicz-Pande@119# (24) whereg(u) is a shape function, and various functions we proposed as follows: g~u!5 2k ~11K !2~12K !sin 3u Argyris-Gudehus@127# (25) This function was improved by Lin-Bazant in@128# and Shi-Yang in@129# as follows: oaded From: http://appliedmechanicsreviews.asmedigitalcollection.asme.org al - , by ere n- d to ere ol- re g~u!5r c 2k~c11c2 cos 3u! ~c31k!1~c32k!cos 3u Lin-Bazant (26) g~u!5 ~712k!22~12k!sin 3u 9 Yang-Shi (27) Elliptic function proposed by Willams and Warnke@120# is g~u!5 ~12K2!~) cosu2sinu! ~12K2!~21cos 2u2) sin 2u!1~122K !2 1 ~2K21!A~21cos 2u2) sin 2u!~12K2!15K224K ~12K2!~21cos 2u2) sin 2u!1~122K !2 (28) Hyperbolic function proposed by Yu-Liu@131# is g~u!5 2~12K2!cosu1~2K21!A4~12K2!cos2 u15K224r t 4~12K2!cos2 u1~K22!2 (29) F5at8 21bt81cs11ds851 Chen @31# (30) F5t8 21c1P~u!t81c2s85C, Podgorski @132# (31) where P5cos@1/3 arccos~cos 3u!2b# F5~at8! 21m@bt8 P~u,l!1cs8#5C Menetrey-Willam @133# (32) F5J31cJ22~12h!c 350, Krenk @134# (33) Some other failure criteria were proposed as follows: F5~)/& !t82k~123s8 /s ttt! a2~3s8 /sccc! b50 Yu-Liu @44# (34) wherea andb are the shape functions, 0<a<1 and 0<b <1. F5t81a~12l!S s81bs812aD a 1alS s81bs813aD b Qu @44# (35) wherel5(sin32u) (0.81 3/21u) F5 sm 12~h/h0! n Shen @135# (36) where h5 1 & F S t12s12D 2 1S t13s13D 2 1S t23s23D 2G1/2 F5J22a1bI1J3 1/35C, Yin-Li et al @136# (37) F5t82aS b2s8c2s8D d Guo-Wang @137,138# (38) wherec5ct(cos 3u/2) 1.51cc(sin 3u/2) 1.5, / on 05/10/2013 Terms of Use: http://asme.org/terms u - b a r i o 6 s r e l n he- ns in r ors e. om- axi- r um r es ly. s- s of ear - - ized gth ion in- y 62 Appl Mech Rev vol 55, no 3, May 2002 Yu: Advances in strength theories 175 Downloaded From F5at8 1.51bt8 cosu1as85C, Zhang-Huang@139# (39) F5at8 21~b1c cosu!t81ds85C, Jiang @44,140# (40) F5t8t1a1s81b1s8 25C1, ~u50°! F85t8c1a2s81b2s8 25C2, ~u560°! Song-Zhao@141,142# (41) wheret8(u)5t8 cos 2(3u/2)1t8 sin 2(3u/2) F5t8 21~As81B!@12~12c!~12cos 3u!#5C, Genev-Kissyuk@27# (42) F5t81As8A12B cos 3u5C, Gudehus@127# (43) Interested readers are referred to reviewing literatu written by WF Chen@31# and Shen-Yu@52#. Some failure surfaces with cross section of quadratic curve and reg triangle were derived from hypo-elasticity by Tokuoka@143#. Two J3-modified Drucker-Prager criteria were proposed Lee and Ghosh in@144#. Another modified von Mises crite rion proposed by Raghava-Cadell for polymers was used viscoplastic analysis by Hu, Schimit, and Francois in@145#. Other yield criteria joining all the three invariants were pr posed by Hashiguchi in@146#, Maitra-Majumdar in@147#, Haddow-Hrudey in@148# et al. 3.2.4 Octahedral shear cap model Druckeret al was upon the first to suggest that soil might modeled as an elasto-plastic work-hardening material~see Section 6.3 of this article!. They proposed that successiv yield functions might resemble Drucker-Prager cones w convex end caps. Based on the same idea of using a ca part of the yield surface, various types of cap models h been developed at Cambridge University.They are refe to as the Cam-clay model and the Modified Cam-clay mod Discussions of various Cambridge models were summar by Parry@149#, Palmer@31#, and Wood@150#. Multi-parameter criterion of SSS theory takes three pr cipal shear stresses and the hydrostatic stress into acc They are the curved failure surfaces mediated between failure surface of the SSS theory~Single-shear strength theory! and the failure surface of the TSS theory~Twin-shear strength theory! proposed and developed in China from 19 to 1990 as shown in Fig. 1. According to Eq.~11!, all the failure criteria of OSS serie strength theory can be expressed in terms of three princ stresst13, t12, and t23. So, this series of strength theo may be also referred to as the three-shear strength th @46#. 3.2.5 Applications of the OSS theory The octahedral-shear stress yield criterion~von Mises crite- rion! has been widely used for metallic materia Octahedral-shear failure criterion~Drucker-Prager criterion! and the octahedral-shear cap model were used in soil chanics and geotechnological engineering, and impleme : http://appliedmechanicsreviews.asmedigitalcollection.asme.org/ on 05/10/2 res lar by for o- e e ith p as ve red el. zed in- unt. the 1 ipal y ory s. me- ted into nonlinear FEM codes. Various multi-parameter octa dral shear failure criteria were used for concrete. It is very interesting, as indicted by Zyczkowski@30#, that various expressions of SSS equations and OSS equatio general form ~13! or its particular cases were late repeated—more or less independently—by many auth @30#. If we utilize Eq. ~11!, many expressions are the sam 3.3 Twin-shear strength theory„TSS theory… It is clear that there are three principal shear stressest13, t12, andt23 in a stressed element. However,t13, t12, and t23 are not independent, there are only two independent c ponents in three principal shear stresses because the m mum principal shear stresst13 equals the sum of the othe two, ie, t135t121t23. So, the idea oftwin-shearwas intro- duced and developed by Yu and Yuet al in 1961-1990@152– 160#. This series of strength theories considers the maxim principal shear stresst13 and intermediate principal shea stresst12 ~or t23!, and the influence of the normal stress s13 ands12 ~or s23! acting on the same section, respective It is referred to as the twin-shear strength theory~TSS theory!, and can be written mathematically as F@t13,t12;s13,s12#5C, when f ~t12,s12!> f ~t23,s23! (44) F8@t13,t23;s13,s23#5C, when f ~t12,s12!< f ~t23,s23! (448) The first criterion in the TSS category was originally po tulated in 1961, and has since developed into a new serie strength theory. Among the main stream are the twin-sh yield criterion ~one-parameter! @151,152#, the generalized twin-shear strength theory~two-parameter! @155#, the twin- shear ridge model@131#, the twin-shear multiple-slip condi tion for crystals@157#, the multi-parameter twin-shear crite rion @158,159#, and the twin-shear cap model@160#. The systematical theories and their applications were summar in a new book@156#. 3.3.1 Twin-shear yield criterion (Yu 1961) This is a one-parameter criterion of the twin-shear stren theory. The idea and expressions of twin-shear yield criter are as follows@152,153#: F5t131t125s12 1 2~s21s3!5ss , when s2< s11s3 2 (45) F5t131t235 1 2 ~s11s2!2s35ss , when s2> s11s3 2 (458) Twin-shear yield criterion is a special case of the Tw shear strength theory@155#. The generalization of the Twin-shear yield criterion b adding a hydrostatic stress term was given by Yu in 19 013 Terms of Use: http://asme.org/terms e n t s u m - e c n r d the r- ia- ully y ro- stic te- f ar- hr- r- t by ials se- re- ia- ed m- ate- ria he eld he ld 176 Yu: Advances in strength theories Appl Mech Rev vol 55, no 3, May 2002 Downl @154#. The limit surface is a pyramid with regular hexagon cross section similar to the yield locus of the twin-shear yi criterion. The expression is F5t131t121bsm5C F5t131t231bsm5C (46) 3.3.2 Twin-shear strength theory (Yu-He 1985) A new and very simple strength theory for geomaterials w proposed by Yuet al @155#. This is a two-parameter criterio of the twin-shear strength theory. The idea and mathema modeling are as follows: F5t131t121b~s131s12!5C, when t121bs12>t231bs23 (47) F5t131t231b~s131s23!5C, when t121bs12<t231bs23 (478) It can be expressed in terms of three principal stresse follows: F5s12 a 2 ~s21s3!5s t , when s2< s11as3 11a (48) F85 1 2 ~s11s2!2as35s t , when s2> s11as3 11a (488) The SD effect and the effect of hydrostatic stress are ta into account in the twin-shear strength theory. The limit s face of the twin-shear strength theory is a hexagonal pyra whose cross sections~in thep plane! are symmetric but non regular hexagons. It is the upper~external! bound of all the convex limit loci as shown in Fig. 1. No admissible conv limit surface may exceed the twin-shear limit surface. 3.3.3 Verifications of the twin-shear strength theory The verifications of the TSS theory were given by Li-X et al @161# and Ming-Sen-Gu@162# by testing the Laxiwa granite of a large hydraulic power station in China and ro like materials under true tri-axial stresses. The twin-sh strength theory predicted these experimental results. T conclusion was also given by comparing the experime data of Launay-Gachon’s tests@163# for concrete and othe experimental data@164–166#. The experimental results o Winstone@167# agreed well with the twin-shear yield crite rion. 3.3.4 Twin-shear multi-parameter criteria The twin-shear strength theory can also be extended various multi-parameter criteria for more complex con tions. The expressions are as follows@158,159#: F5t131t121b1~s131s12!1A1sm1B1sm 2 5C (49) F5t131t231b2~s131s23!1A2sm1B2sm 2 5C (498) whereb,A,B,C are the material parameters. 3.3.5 Twin-shear cap model Twin-shear cap model was proposed by Yu and Li@160#. It has been implemented into an elasto-plastic FE program oaded From: http://appliedmechanicsreviews.asmedigitalcollection.asme.org al ld as ical as ken r- id x u k- ear his tal f - into i- . 3.3.6 Applications of the TSS theory TSS theory~twin-shear series of strength theory! has pushed the strength theory study to a new advance by forming upper~outer! bound for all the possible convex failure su faces coincided with the Drucker postulation on the dev toric plane in stress space as shown in Fig. 1. The twin-shear yield criteria had been used successf in the plane strain slip line field by Yu-Liu@168#, plane stress characteristic field by Yan-Bu@169–171#, metal forming by Zhaoet al @172–176#, and limiting analysis of structures b Li @177#, Huang-Zeng@178#, JJ Chen@179#, Wang@180#, etc. TSS theory was implemented into some finite element p grams by Anet al @181#, by Quint Co@182–184#, etc, and applied in elasto-plastic analysis and elasto-visco-pla analysis of structures by Li-Ishii-Nakazato@185#, Luo-Li @186#, Li and Ishii @187#, and Liuet al @188#. TSS theory was also applied in the plasticity of geoma rials by Zhang@189# and Zhu @190#, in wellbore analysis @191#, in gun barrel design@192#, punching of concrete slab @193#, and soil liquefaction@194#, etc. Some applications o the twin-shear strength theory can be seen in@195–199#. The results of the applications indicate that it could raise the be ing capacities of engineering structures more than the Mo Coulomb’s, ie, improves on the conservative Moh Coulomb’s. So, there is a considerable economical benefi using the new approach if the strength behavior of mater is adaptive to the twin shear theory@156,185#. Three series of strength theories, ie, SSS series, OSS ries, and TSS series are summarized briefly in Table 1. 4 YIELD CRITERIA FOR METALLIC MATERIALS Many articles and books, as indicated in Table 1, have viewed this object. We will supplement the maximum dev toric stress criterion, or twin shear criterion, and the unifi yield criterion in Section 5. Some experimental data are su marized as shownin Table 2. The experimental results are taken from Guest@62#, Scoble@200,201#, Smith @202#, Lode @203#, Taylor-Quinney @204#, Ivey @205#, Paul@18#, Bell @22#, Michno-Findley@25#, Pisarenko-Lebedev@206#, and others@207–219#. The dis- crepancies among different experiments and different m rials are large. Up to now, none of the above yield crite agreed with the experiments for different materials. After t comparison of the shear yield strength and tensile yi strength for thirty materials, Kishkin and Ratner@220# di- vided the metals into four kinds according to the ratio of t shear yield strength with tensile yield strengthts /ss as fol- lows: a) ts /ss,0.40 ~0.31–0.41, eight materials!. It is a non- convex result, no yield criterion agreed b) ts /ss>0.50~0.48–0.53, five materials!. It is agreed with the single-shear yield criterion~Tresca yield criterion! c) ts /ss>0.58~0.54–0.62, nine materials!. It is agreed with the tri-shear yield criterion~von Mises yield criterion! d) ts /ss>0.68 ~0.67–0.71, eight materials!. It is agreed with the twin-shear yield criterion. Four sets of experimental results of Winstone@167# show that the initial yield surfaces indicated a ratio of shear yie / on 05/10/2013 Terms of Use: http://asme.org/terms ises Mises Mises Appl Mech Rev vol 55, no 3, May 2002 Yu: Advances in strength theories 177 Downloaded From Table 2. Comparison of three yield criteria with experimental results Researchers Materials Specimen shearÕtension ty /sy Suitable Criterion Guest, 1900 steel, 0.474, 0.727 Guest, 1900 steel, brass, etc. tubes 0.474 Hancok, 1906,1908 mild steel solid rods,tube 0.50 to 0.82 Scoble, 1906 mild steel solid rods 0.45 to 0.57 Tresca Smith, 1909 mild steel solid rods 0.55-0.56 between Tresca and von M Turner, 1909-1911 steels 0.55 to 0.65 Tresca Mason, 1909 mild steel tubes 0.5 0.64 Tresca Scoble,1910 steel 0.376, 0.432, 0.452 no one agreed Becker, 1916 mild steel tubes no one agreed Seeley and Putnam steels bars & tubes 0.6 . von Mises Seigle and Cretin, 1925 mild steel solid bars 0.45 to 0.49 Tresca Lode, 1926 iron, copper etc. tubes von Mises Ros and Eichinger, 1926 mild steel tubes von Mises Taylor and Quinney, 1931 aluminum, steel tubes von Mises copper, mild steel .von Mises Morrison, 1940 mild steel tubes Tresca, von Mises Davis, 1945-1948 copper, tubes von Mises Osgood, 1947 aluminum alloy tubes von Mises Cunningham, 1947 magnesium alloy tubes von Mises Bishop-Hill, 1951 polycrystals tubes 0.54 von Mises Fikri, Johnson, 1955 mild steel tubes . von Mises Marin and Hu, 1956 mild steel tubes von Mises Naghdi, Essenberg, and Koff, 1958 aluminum alloy tubes . von Mises Hu and Bratt, 1958 aluminum alloy tubes von Mises Ivey, 1961 aluminum alloy tubes Twin shear Bertsch-Findley, 1962 aluminum alloy tubes von Mises Mair-Pugh, 1964 copper tubes Twin shear Mair-Pugh, 1964 copper tubes von Mises Chernyaket al, 1965 mild steel tubes von Mises Miastkowski, 1965 brass von Mises Rogan, 1969 steel tubes Tresca Mittal, 1969, 1971 aluminum tubes 0.57 von Mises Dawson, 1970 polycrystals 0.64 near Twin shear Phillips et al, 1968- 1972 aluminum tubes at elevated temperature between Tresca and von Deneshiet al, 1976 aluminum, copper tubes, low temperature 0.6 . von Mises Pisarenkoet al, 1984 copper, Cr-steel tubes, low temperature von Mises Winstone, 1984 nickel alloy tubes at elevated temperature 0.7 Twin shear Ellyin, 1989 titanium tubes 0.66-0.7 Twin shear Wu-Yeh, 1991 Aluminum tubes 0.58 von Mises stainless steel 0.66-0.7 Twin shear Ishikawa, 1997 stainless steel tubes 0.6-0.63 . von Mises Granlund,Olsson, 1998 structural steel flat cruciform specimens between Tresca and von l es e ld in . nt. d - e stress to tensile yield stress of 0.7. He said: ‘‘The ratio of torsion shear yield stress to tensile yield stress is>0.7, sur- prisingly high when compared with the values of 0.58 and 0.5 expected from the von Mises and Tresca yield criteria, respectively. Clearly neither of these criteria can accurately model the bi-axial yield behavior of Mar-M002 castings.’’ @167# The Tresca and von Mises yield criteria excepted, Hay- thornthwaite proposed a new yield criterion@90#. This new yield criterion is referred to as the maximum reduced stress ~deviatoric stress! Smax yield criterion f 5Smax51/3~2s12s22s3!52/3sS (50) The similar idea of maximum deviatoric stress criterion may be traced back to the deviatoric strain~shape change! by Schmidt in 1932@30# and Ishlinsky in 1940@222#, and the linear approximation of the von Mises criterion by Hill in 1950 @18,223#, then first proposed independently from the idea of maximum deviatoric stress by Haythornthwaite in 1961 @90#. The expression of Hill was f 5~2s12s22s3!5msS (51) Comments to this criterion were made by Paul@18# and by Zyczkowski@30#. Another new idea was proposed by Yu@152#. It assumed that yielding begins when the sum of the two larger principa shear stresses reaches a magnitudeC. It is clear that only two principal shear stresses in three principal shear stress t13, t12, andt23 are independent variables, because of th maximum principal shear stresst13 equals the sum of the other two. So, it is referred to as the twin-shear stress yie criterion that is given in Eqs.~44! and ~448!. The twin-shear yield criterion can also be introduced from the generalized twin-shear strength theory proposed by Yu 1985@155# ~whena51 in Eq.~46!!. This yield surface is the upper~outer! bound of all the convex yield surfaces. All the yield criteria, including the Tresca, von Mises, and twin-shear yield criterion are single-parameter criterion Many researchers followed Bridgman@224–228# and as- sumed that materials are hydrostatic pressure independe Numerous experiments carried out by Bridgman~1882- 1961! at Harvard proved that the yielding of metals is unaf- fected by hydrostatic pressure. His experiments include thirty metals. Most non-metallic materials, however, are hy drostatic pressure dependent@229–233#. The yield criteria had been used successfully in the plan strain slip line field by Hencky@234#, Geiringer @235#, Prandtl@236–238#, Prager@239,240#, Johnson@241#, Yu et al : http://appliedmechanicsreviews.asmedigitalcollection.asme.org/ on 05/10/2013 Terms of Use: http://asme.org/terms e o d i l g pic . nd pic re en on- e- b- e 178 Yu: Advances in strength theories Appl Mech Rev vol 55, no 3, May 2002 Downl @168#, and others. The uses of yield criterion in plane str characteristic field and axisymmetric characteristic field a metal forming can be seen in Kachanov@242#, Yan-Bu@169– 171#, Hill @243#, Haar-von Karman@244#, Sokolovski@245#, and Thomsen-Yang-Kobayash,@247#, etc. The applications in damage and yield of ductile media with void nucleati can be found in Gurson@248,249#, Tvergaard@250–252#, Gologanu-Leblond-Perrin-Devaux@253# et al. Limiting analysis and elasto-plastic analysis of structures by using yield criteria can be seen in Drucker@254,255#, Hodge@256#, and Saveet al @257#. The implementations of various yiel criteria to variety finite element programs were summariz by Brebbia in@258#. However, how to choose a reasonab yield criterion is an important problem. It is still a problem to find a unified yield criterion that ca be applicable to more than one kind of material and estab the relationship among various yield criteria. 5 UNIFIED YIELD CRITERIA 5.1 Curved general yield criteria 5.1.1 Curved general yield criterion between SS and OS yield criteria A curved general yield criterion lying between SS~Single- shear, Tresca! and OS~Octahedral-shear, von Mises! criteria was proposed by Hershey in 1954@259#, Davis in 1961 @260,261#, Paul in 1968@18#, Hosford in 1972@262#, Barlat- Lian in 1989 @263#, and explained by Owen & Peric@264# et al as follows: f 15~S12S2! 2k1~S22S3! 2k1~S32S1! 2k52ss 2k or f 15us22s3um1us32s1um1us12s2um52ss 2k (52) This expression is a generalization of Bailey’s flow ru @260# for combined stress creep by Davis@261# as a yield surface lies insidethe von Mises yield criterion and outs the Tresca yield criterion. This kind of yield criteria is som times called the Bailey-Davis yield criterion. 5.1.2 Curved general yield criteria between OS and yield criteria The curvilinear general yield criteria lying between the O yield criterion ~octahedral shear yield criterion! and the TS yield criterion ~twin-shear yield criterion! were proposed by Tan in 1990@265# and Karafillis & Boyca in 1993@266#. The expression is f 5S1 2k1S2 2k1S3 2k5 22k12 32k ss 2k (53) 5.1.3 Curved general yield criteria between SS and yield criteria Tan @265# and Karafillis & Boyca@266# obtain a genera yield criterion lying between the lower bound~SS yield cri- terion! and the upper bound~TS yield criterion! yield crite- rion as follows: f5~12c! f 11c 32k 22k2111 f 2 , cP@0,1# (54) oaded From: http://appliedmechanicsreviews.asmedigitalcollection.asme.org ss nd n the ed le n lish le de e- TS S TS 5.1.4 Drucker criterion Edelman and Drucker suggested the following criterion@82# J2 32CdJ3 25F (55) Dodd-Narusec@267# extended this equation in the followin expression ~J2 3!m2Cd~J3 2!m5Fm (56) It is a series of curved yield criteria~m51 or m52! lying outside the SS~Tresca! yield criterion. 5.1.5 Hosford criterion Hosford @262# proposed a criterion as follows @ 12 ~s12s2! m1 12 ~s12s3! m#1/m5ss (57) A series of yield criteria can be given whenm51 to m 5`. 5.1.6 Simplification of anisotropic yield criterion Hill proposed a new yield criterion as follows@268# f us22s3um1gus32s1um1hus12s2um1Cu2s12s2 2s3um1u2s22s12s3um1u2s32s12s2um5ss m (58) where m>1, the six parametersf , g, h, a, b, and c are constants characterizing the anisotropy. For the isotro case, f 5g5h, a5b5c, it is three-parameter criterion Dodd and Naruse@267# take f 5g5h51, from which it fol- lows that f 5us22s3um1us32s1um1us12s2um1Cu2s12s2 2s3um1u2s22s12s3um1u2s32s12s2umss m (588) A series of curved yield criteria between SSS criterion a TSS criterion can be given whenm51 to m5`. Similar yield criteria can also be introduced from the anisotro yield criteria of Hosford @262# and Barlat et al @263,269,270,735#. All the generalized yield criteria mentioned above a smooth, convex, and curvilinear yield criteria lying betwe single-shear and twin-shear yield criteria. They are the n linear unified yield criteria. However, they are not conv nient to use in the analytic solution of elasto-plastic pro lems. 5.2 Linear unified yield criterion 5.2.1 Unified yield criterion A new linear unified yield criterion was introduced from th unified strength theory by Yu-He@271–274#. The mathemati- cal modeling is f 5t131bt125C, when t12>t23 (59) f 85t131bt235C, when t12<t23 (598) / on 05/10/2013 Terms of Use: http://asme.org/terms a i s i e c b 9 r i- i- - re. ults It to ith he he re n e- - Appl Mech Rev vol 55, no 3, May 2002 Yu: Advances in strength theories 179 Downloaded From whereb is a coefficient of the effect of the other princip shear stresses on the yield of materials. The unified y criterion can be expressed in terms of three principal stre as follows f 5s12 1 11b ~bs21s3!5ss , when s2< 1 2 ~s21s3! (60) f 85 1 11b ~s11bs2!2s35ss , when s2> 1 2 ~s21s3! (608) It is a linear unified yield criterion. It contains two fam lies of yield criterion: one is the convex unified yield crit rion lying between the single-shear and twin-shear yield teria ~when 0<b<1!. Another is the non-convex yield criterion lying outside the twin-shear yield criterion~when b.1! or lying inside the single-shear yield criterion~when b,0!. So, it can be predicted to most results listed in Ta 2. This unified yield criterion encompasses the single-sh ~Tresca! yield criterion ~whenb50!, twin-shear yield crite- rion ~when b51!, and the octahedral-shear yield criterio ~von Mises! as special cases or linear approximationb 51/2). A lot of new linear yield criteria can be also intro duced@272#. It can be adopted for all the metallic materia with the same yield strength both in tension and compr sion. The linear unified yield criterion is also a special ca of the unified strength theory proposed by Yu in 19 @271,272#, which will be described in Section 7 of this a ticle. The varieties of the yield loci of this unified yield crite rion at thep plane and plane stress are shown in Fig. 2 a Fig. 3. : http://appliedmechanicsreviews.asmedigitalcollection.asme.org/ on 05/10/2 l eld ses - - ri- le ear n ( - ls es- se 1 - - nd 5.2.2 Extension of the unified yield criterion The relationship between shear yield stressts and tensile yield stressss of materials can be introduced from the un fied yield criterion as follows ts5 11b 21b ss or at5 ts ss 5 11b 21b (61) It is shown that:~1! The shear strength of ductile mater als is lower than tensile strength;~2! Yield surfaces are con vex when 0<b<1 or 1/2<at<2/3; ~3! Yield surfaces are non-convex whenb,0 andb.1; or the ratio of shear yield stress to tensile yield stressat,1/2 andat.2/3. 5.2.3 Non-convex yield criterion Non-convex yield criterion was merely investigated befo The unified yield criterion can be used to describe the res of ts /ss,0.5 (b,0) andts /ss.2/3, (b.1). It is a non- convex result. Recently, Wang and Dixon@275# proposed an empiric failure criterion in (s2t) combined stress state. can be fitted in with those experimental results in (s2t) combined stress state of Guest@62#, and Scoble@200,201# with ts /ss50.376, 0.432, 0.451, and 0.474. It is easy match these results by using the unified yield criterion w b520.4, b520.24, b520.18, andb520.01, respec- tively. 5.2.4 Applications of the unified yield criterion The linear unified yield criterion is convenient to use in t analytical solution of elasto-plastic and other problems. T unified solutions of simple-supported circular plate we given by Ma-He@276# and Ma-Yuet al @277,278#. Ma, Yu, and Iwasakiet al also gave the unified elasto-plastic solutio of rotating disc and cylinder by using the unified yield crit rion @279#. The unified solutions of limiting loads of rectan gular plate and oblique plates were obtained by Zaoet al @280# and Li, Yu, and Xiao@281#, respectively. ss Fig. 2 Varieties of the unified yield criterion inp plane@271,272# Fig. 3 Varieties of the unified yield criterion in plane stre @271,272# 013 Terms of Use: http://asme.org/terms t f m u t o b e e ated als xial two nd n all d of gh s. ion ral st x lane tress on res- Mo- ure he , al- as s- ress e ork- true 180 Yu: Advances in strength theories Appl Mech Rev vol 55, no 3, May 2002 Downl The further studies of limit speeds of variable thickne discs using the unified yield criterion were given by M Hao, and Miyamoto in 2001@282#. The plastic limit analyses of clamped and simple-supported circular plates with resp to the unified yield criterion were obtained by Guowe Iwasaki-Miyamotoet al @283#, and Ma, Haoet al @284,285#. The dynamic plastic behavior of circular plates using unified yield criterion was studied by Ma, Iwasakiet al @286#. Qiang and Xuet al @287# gave the unified solutions o crack tip plastic zone under small scale yielding and the li loads of rectangular plate, etc, respectively, by using the fied yield criterion. A series of results can be introduced fro these studies. Some research results concerning the yield criterion w given in @288–318#. All the yield criteria including the Tresca criterion, vo Mises criterion, twin-shear criterion, and the unified yie criterion can be adopted only for those materials with sa yield stress in tension and in compression. They canno applied to rock, soil, concrete, ice, iron, ceramics, and th metallic materials which have the SD effect~strength differ- ence at tension and compression!. The SD effects of high strength steels, aluminum alloys, and polymers were served in 1970s, eg, Chait@319#, Rauch and Leslie@320#, Drucker @321#, Richmond and Spitzig@322#, and Casey and Sullivan et al @323#. The SD effect is related to the effect o the hydrostatic stress.The hydrostatic pressure produce fects increasing the shearing capacity of the materials. fects of hydrostatic pressure on mechanical behavior and formation of materials were summarized recently Lewandowski and Lowhaphandu@324#. The effects of hy- drostatic stress and the SD effect of metals, rock, polym etc were summarized recently by Yu in 1998@156#. The generalized failure criteria considering the SD eff and the influence of hydrostatic stress have to be used. limit loci of the generalized failure criteria considering th SD effect and the influence of hydrostatic stress are show Fig. 1. The Mohr-Coulomb strength theory@70# and the Yu’s twin-shear strength theory@155# are two bounds of all the convex criteria. oaded From: http://appliedmechanicsreviews.asmedigitalcollection.asme.org ss a, ect i, he it ni- m ere n ld me be se ob- f s ef- Ef- de- y rs, ct The e n in 6 FAILURE CRITERIA FOR SPECIFIC MATERIALS The development of strength theories is closely associ with that of the experimental technology for testing materi in complex stress states. A considerable account of tria stress tests were done in the 20th century. There are kinds of triaxial tests. In most laboratories, for triaxial tests, cylindrical rock a soil specimens are loaded with an axial stresssz5s1 ~or sz5s3!, and a lateral pressures25s3 ~or s25s1!; both can be varied independently, but alwayss25s3 ~or s2 5s1!. The first research seems to be due to Foppl@64#, von Karman@71#, and Boker@72#. Von Karman and Boker were supervised under Prandtl. Today such tests are done i rock mechanics and soil mechanics laboratories. This kin test, unfortunately, is usually called the triaxial test, althou it involves only very special combinations of triaxial stres It is better to refer to this test as the confined compress test, since it is a compression test with a confining late pressure@18#. Sometimes it is called the untrue triaxial te or false triaxial test. All the combinations of comple stresses in a confined compression test lie on a special p in stress space. So, most triaxial tests are only a plane s test. In 1914, Boker retested the type of marble used by v Karman in a confined pressure test in which the lateral p sure was the major principal stress. The corresponding hr’s envelope did not agree with von Karman’s~in von Kar- man’s tests, the axial pressure exceeded the lateral press!. This means that the Mohr-Coulomb criterion could not fit t data adequately in the range of low hydrostatic pressure though the more general hexagonal pyramid criterion w not ruled out@18,72#. It is evident that the confined compre sion test is not capable of proving that the intermediate st is of no influence on the failure criterion. Another is seldom a true tri-axial test, in which all thre principal stresses can be varied independently. Several w ers have designed specialized equipment for conducting triaxial test, eg, Shibata-Karube@91#, Mogi @92,93,325–328#, Launay-Gachon@163#, Desai et al @333#, Hunsche@336#, Fig. 4 Effect of the intermediate principal stress@355# Fig. 5 Effect of the intermediate principal stress@98,99# / on 05/10/2013 Terms of Use: http://asme.org/terms , t i n u L e t s s ri- ess- gn y n- b- ses nd ical ies lts. nce, tes, nd l e ry- - ized tro- s for her der gher or- ous Appl Mech Rev vol 55, no 3, May 2002 Yu: Advances in strength theories 181 Downloaded From Ming et al @162#, Xu-Geng@349#, Michelis @98,99#, Li, Xu, and Geng@350#, Mier @348#, and Wawersik, Carsonet al @345#. A great amount of effort was dedicated to the develo ment of true-triaxial testing facilities, and the facilities we then used to test engineering materials. Some represent efforts were seen on rocks at Tokyo University and others soil at Cambridge University, Karlsruhe University, Kyo University, and others, and on concrete in Europe and United States. Mogi’s persistent effort revealed that rock strength var with the intermediate principal stresss2 , which was quite different from what had been depicted in the conventio Mohr-Coulomb theory. The study was further extend @346,353,354# to a understanding that thes2 effect had two zones: the rock strength kept on increasing, whens2 built up its magnitude froms3 , until reaching a maximum value beyond that, the rock strength decreased with the further crease ofs2 . Xu and Geng also pointed out that varyings2 , only, while keeping the other principal stressess1 and s3 unchanged, could lead to rock failure, and this fact co also be attributable to inducing earthquakes@347#. Michelis indicated that the effect of intermediate principal stress is essential behavior of materials@98,99#. Figures 4 and 5 are taken from Mazanti-Sowers@355# and Michelis@98,99#. The effect of the intermediate principal stress on rock is evide On a modified high pressure true tri-axial test facility, and his colleagues@161,350# tested some granite and show that thes2 effect is significant. This result is consistent wi the twin-shear strength theory. Ming and his coworkers@162# and Lu @358,359# also reached the same conclusion. Most true tri-axial tests are three compressive stres Triaxial tension-compression tests for multiaxial stres were done by Ming, Shen, and Gu@162#, and by Calloch and Marquis@344#. A true triaxial cell for testing cylindrical rock specimens was developed by Smartet al @341–343#. This true triaxial cell can be suited for testing cylindrical roc specimens. ept ergy for e : http://appliedmechanicsreviews.asmedigitalcollection.asme.org/ on 05/10/2 p- re ative on o the ed al ed ; in- ld the nt. i d h es. es k Recently, at the University of Wisconsin, a new true t axial testing system was designed, calibrated, and succ fully tested by Haimson and Chang@356#. It is suitable for testing strong rocks, which emulates Mogi’s original desi @93# with significant simplifications. Its main feature is ver high loading capacity in all three orthogonal directions, e abling the testing to failure of hard crystalline rocks su jected to large minimum and intermediate principal stres @346#. A mathematical proof regarding the twin-shear theory a the single-shear theory was given by citing the mathemat concept of convex sets@360,361#. It is shown that the twin shear strength theory is the exterior~upper! bound and the single-shear theory is the interior~lower! bound of all the convex limiting loci on thep plane as shown in Fig. 1. The true tri-axial tests on concrete bear many similarit with that on rocks, both in testing facilities and test resu Many such tests have been reported by researchers in Fra Japan, Germany, the former Soviet Union, the United Sta and China. Through numerous true tri-axial tests on both rock a concrete, the existence of thes2 effect has now been wel recognized as characteristic of these materials@90–99, 137– 142, 325–328, 346–373#. Figure 6 shows the effects of th intermediate principal stress of concrete given by Launa Gachon in 1972@163#. The effects of the intermediate prin cipal stress of metals, rock, concrete, etc were summar by Yu in 1998@156#. In the United States, an enhancement factor was in duced in the ACI Standard@362# guiding designs of pre- stressed concrete pressure vessels and safety shell nuclear power station as shown in Fig. 7. This standard and many experimental results allow hig permissible strength to be used in concrete and in rock un triaxial compression stress states, and hence lead to hi economical effectiveness in construction use. More imp tantly, the impact of the concept is expected to be enorm to the design of ordinary engineering structures. The wider application of the enhancement-factor conc on a global scale is, on one hand, to bring tremendous en saving and pollution curbing; it calls, on the other hand, Fig. 6 Effects of the intermediate principal stress of concr @163# te Fig. 7 Enhanceds2 effect in concrete strength@362# 013 Terms of Use: http://asme.org/terms s v p r c e r e l l iri- ss al ated m , L ns sof a gth ted r- ffect eri- ults ck und in of ip- ci- nd lted iven ing r as A o- d nd 182 Yu: Advances in strength theories Appl Mech Rev vol 55, no 3, May 2002 Downl a theoretical support on which the concept could be ba The engineering practice in general has a desire to ha new strength theory, which should be more rational and m consistent to the experimental data than what can be don the Mohr-Coulomb single-shear strength theory. Some f ure criteria~Tresca, von Mises, Mohr-Coulomb, and max mum tensile stress theory! were reviewed by Shaw@35#. 6.1 Failure criteria for rock Up to now, more than 20 strength~yield or failure! criteria for rocks have been developed, but only a few of the crite are widely used in rock engineering. Failure criteria of roc were summarized by Jaeger and Cook@363#, Lade@122,364#, Andreev@45#, and Sheorey@50#. Various researches and a plications can be found in@363–438#. The Mohr-Coulomb theory is the most widely applie one. Some other nonlinear Mohr-Coulomb criteria similar the Hoek-Brown criterion were summarized in the literatu of Andrew @45# and Sheorey@50#. The Ashton criterion was extended by JM Hill and YH Wu@365#. All the Mohr- Coulomb, Hoek-Brown, and most kinds of empirical ro failure criteria ~Eqs. ~4!–~7!! only take thes1 and s3 into account. They may be referred to as the single-shear stre theory (t135(s12s3)/2). The effects of the intermediat principal stresss2 were not taken into account in these c teria ~see Eqs.~3!–~7!!. The general form of these failur criteria may be expressed as follows: F5 f 1~s12s3!1 f 2~s11s3!1 f 3~s1!5C (62) Some single-shear type failure criteria for rock are given section three~Eqs.~4!–~7!!, the other two failure criteria for rock are s12s35sc1as3 b Hobbs @366# (63) s12s35a~s11s3! b Franklin @367# (64) Mogi @92,93,325–328# proposed a combined failure criterio of octahedral shear stressest8 ands13 for rock as follows: F5t81A~s11s3! n, F5t81 f ~s11as21s3! or F5t131bs131Asm5C, F5s12as31Asm5C (65) The von Mises-Schleicher-Drucker-Prager criterion w modified and applied to rock by Aubertin, L Li, Simon, an Khalfi @368#. The strength tests for various rocks under the action complex stresses were conducted by Foppl@64#, Voigt @65#, von Karman@71#, Boker @72#, Griggs @370#, Jaeger@371#, Mogi @91,92,325–328#, Michelis @98,99# et al Many experi- mental investigations were devoted to the studies on the fect of the intermediate principal stress, eg, Murrell@372#, Handin et al @375#, Mogi @325–328,385#, Amadei et al @398,406#, Kim-Lade @401#, Michelis @98,99,409#, Desai @403–405#, Yin et al @136#, Gao-Tao@357#, Wang, YM Li, and Yu@166#, Lu @164,165,358,359#, and others. Some octa hedral shear type criteria~OSS theory! for rocks were pro- posed which included the failure criterion for natural po crystalline rock salt by Hunsche@336,408,410#. oaded From: http://appliedmechanicsreviews.asmedigitalcollection.asme.org ed. e a ore e by ail- i- ria ks - d to es k ngth i- in n as d of ef- - y- According to Wang and Kemeny@416#, s2 has a strong effect ons1 at failure even ifs3 equals zero. Their polyaxia laboratory tests on hollow cylinders suggested a new emp cal failure criterion in which the intermediate principal stre was taken into account. Effect of intermediate princip stress on strength of anisotropic rock mass was investig by Singh-Goel-Mehrotraet al @422#. The Mohr-Coulomb theory was modified by replacings3 by the average ofs2 ands3 . A multiaxial stress criterion for short- and long-ter strength of isotropic rock media was proposed by Aubertin Li, Simon et al @368,369#. Vernik and Zoback@427# found that use of the Mohr- Coulomb criterion in relating borehole breakout dimensio to the prevailingin situ stress conditions in crystalline rock did not provide realistic results. They suggested the use more general criterion that accounts for the effect on stren of the intermediate principal stress. Recently, Ewy repor that the Mohr-Coulomb criterion is significantly too conse vative because it neglects the perceived strengthening e of the intermediate principal stress@428#. The twin-shear strength theory was verified by the exp mental results of XC Li, Xu, and Liuet al @161,350#, Gao- Tao@357#, and Ming, Sen, and Gu@162#. The comparisons of the twin-shear strength theory with the experimental res presented in literature were given by Lu@164,165,358,359#. The applications of the twin-shear strength theory to ro were given by Li, Xu, and Liuet al @350#, An, Yu, and X Wu @181#, and Luo and ZD Li@186# et al This strength theory has been applied to the stability analyses of the undergro cave of a large hydraulic power station at the Yellow River China@161,350,429,430#. It was also used in the research the stability of the high rock slopes in the permanent sh lock at three Gorges on the Yangtze River by Yangtze S ence Research Institute in 1997@432–433#, and the analysis of ultimate inner pressure of rings@438#. The twin-shear strength theory was introduced by Sun@436# and Yang@437# to rock mechanics. The strength criteria of rock joints were described a reviewed by Jaeger@439#, Goodman@441#, Zienkiewicz- Valliappan-King @442#, Barton @439–446#, Ghaboussi- Wilson-Isenberg@447#, Singh@448,449#, Ge @450#, Shiryaev et al @451#, Stimpson@452#, Heuze-Barbour@455#, Desai- Zaman@456#, Lei-Swoboda-Du@459#, and recently by Zhao @461,463#, WS Chen, Feng, Ge, and Schweiger@464# et al. A series of conferences on Mechanics of Joint and Fau Rock ~MJFR! were held@462#. The systematical researches on rock rheology were g by Crestescu@407# and Sun@435#. The threshold associated with the onset of microcrack was seen as a yield criterion for an elasto- plastic model o a damage initiation criterion in a state variable model. multiaxial damage criterion for low porosity rocks was pr posed by Aubertin and Simon@418#. A monogragh on Advanced Triaxial Testing of Soil an Rock was published by the American Society for Testing a Materials~Donagle, Chaney and Silver, eds@339#!. / on 05/10/2013 Terms of Use: http://asme.org/terms e c a r a r h , g e R C d a t ore ince - eal ies tion ises ar- ch on. ly as- est ess ion l ost ohr- av- it of x in- vior and hat at - of ter- nifi- rep- sand, se.’’ of arly at Appl Mech Rev vol 55, no 3, May 2002 Yu: Advances in strength theories 183 Downloaded From 6.2 Failure criteria for concrete Failure criteria for concrete including high strength concre light concrete, steel fibre concrete, etc were studied by m researchers@465–536#. Various criteria for concrete wer proposed by Bresler and Pister@465,466#, Geniev @27#, Mills-Zimmerman@471#, Buyukozturk-Liu-Nilson-Slate, and Tasuji @473#, HC Wu @476#, Willam-Warnke@120#, Ottosen @485#, Cedolin-Crutzen-Dei Poli@480#, Hsieh, Ting, and WF Chen@492#, Dafalias@478#, Yang-Dafalias-Herrmann@496#, Schreyer-Babcock@499,507#, de Boeret al @505#, Faruque and Chang @508#, Jiang @44,140#, Song-Zhao-Peng @141,142,516,518#, Voyiadjis and Abu-Lebdeh@514,517#, Labbane, Saha, and Ting@515#, Menetrey-Willam@133#, JK Li @523# et al In general, these criteria are the OSS theory~Octahedral- Stress Strength theory! as described above~Eqs.~12!–~44!!. WF Chenet al @31,41#, Zhang@189#, and Jiang@44# made a general survey of these criteria. A microplane model for clic triaxial behavior of concrete was proposed by Baz and Ozbolt@512,513#. Recently, a key paper@51# entitled ‘‘Concrete plasticity: Past, present, and future’’ was p sented in theProceedings of ISSTAD ’98~International Sym- posium on Strength Theory: Application, Development a Prospects for the 21st Century!. The yield criteria of concrete used in concrete plasticity were summarized by WF Ch @51#. Great contributions in the research of fracture and f ure of concrete are due to Bazant@79,129,482,486,503# and others. A failure criterion for high strength concrete was p posed by QP Li and Ansari@526,527# at ISSTAD ’98. Smooth limit surfaces for metals, concrete, and geotechn materials was proposedby Schreyer@499,507#. A new book entitled,Concrete Strength Theory and its Applications, was published recently@504#. Considerable experimental data regarding the strengt concrete subjected to multi-axial stresses were given, eg chartet al @229#, Balmer@230#, Bresler and Pister@465,466#, Kupfer et al @470#, Launay and Gachon@163#, Kotsovos and Newman @479#, Tasuji et al @484#, Ottosen@485#, Gerstle @489–491#, Michelis @98,99#, Song and Zhao @141,142,516,518#, Wang-Guo @137,138#, Traina-Mansor @510#, et al. Lu gave some applications of the twin-shear stren theory for concrete under true triaxial compressive st @164,165,358,359#. The solution of the axisymmetrica punching problem of concrete slab by using the twin-sh strength theory was obtained by Yan@193#. The application of the unified strength theory~see next section! to concrete rectangular plate was given by Zao@533#. The strength theory of concrete was also applied to ~reinforced concrete! and the nonlinear FEM analysis of R structures by Nilsson@537#, Villiappan-Doolan @538#, Zienkiewicz-Owen-Phillips @539#, Argyris-Faust-Szimmat et al @540#, Buyukozturk @541#, Bathe-Ramaswang@542#, Chen @31#, Bangash@543#, Jiang@44#, et al The twin-shear strength theory and the unified strength theory were use finite element analysis of reinforced concrete beams plate by Guo-Liang@545#, Wang@547#, and others. : http://appliedmechanicsreviews.asmedigitalcollection.asme.org/ on 05/10/2 te, any y- nt e- nd en il- o- ical of Ri- th ate l ar C in nd Damage model for concrete@506,517#, multi-axial fatigue @504#, bounding surface model@496#, blast and hard impac damaged concrete@529#, etc were proposed. 6.3 Failure criteria for soils The behavior of soil under the complex stress state are m complex. Many studies were devoted to these problems s the 1960s@549–627#. In classical soil mechanics, soil prob lems have generally been solved on the basis of an id elastic soil, where the deformation and stability propert are defined by a single value of strength and deforma modules. Sometimes, the Tresca criterion and the von M criterion were used. More sophisticated solutions of the be ing capacity problem involving contained plasticity approa reality more closely by use of the elasto-plastic idealizati The Mohr-Coulomb failure criterion was the most wide used in soil mechanics. However, the failure mechanism sociated with this model is not verified in general by the t results, and the influence of the intermediate principal str is not taken into account. An extended von Mises criter was proposed by Drucker and Prager in 1952@117# and now is refereed as the Drucker-Prager criterion. Although it is widely used, the Mohr-Coulomb mode does not yield agreement with experimental data for m materials. Furthermore, the great disadvantage of the M Coulomb model at present is the lack of indication of beh ior in the direction of the intermediate principal stress, and gives far too much deformation. Previous researches Habib @549#, Haythornthwaite~remolded soil! @551,552#, Broms and Casbarian@555#, Shibata and Karube~clay! @91#, Bishop and Green@83,91,95,105,556#, Ko and Scott@94#, Sutherland and Mesdary@563#, Lade and Duncan@122,564#, Green@561,562#, Gudehus@127,128,588#, Matsuoka, Nakai et al @121,577,601#, Lade and Musante~remolded clay! @97#, Vermeer @569,589#, Dafalias-Herrmann~boundary surface! @581#, Tang ~sand! @571#, Fang @591#, de Boer @505,600#, Xing-Liu-Zheng ~loess! @603#, Yumlu and Ozbay@417#, Wang-Ma-Zhou~dynamic characteristics of soil in comple stress state! @614#, and others have indicated appreciable fluences of the intermediate principal stress on the beha involved in the stress-strain relations, pore pressure, strength characteristics of most materials. It is obvious t the third stress~the intermediate principal stress! influences all three principal strains and the volumetric strain. After many studies, Green@562# came to the following conclusion in the Roscoe Memorial Symposium held Cambridge University in 1971: ‘‘Mohr-Coulomb failure cri terion will tend to underestimate the strength by up to 5° cohesive angle for the dense sand as the value of the in mediate principal stress increases. This would be a sig cant error in many analyses of engineering problems but resents an extreme case in as much as medium dense loose sand, and probably most clays show a small increa Bishop @105,556# also indicated that the failure surfaces extended Tresca and extended von Mises criteria are cle impossible for a cohesionless material. At the same Symposium, Harkness@108# indicated that: ‘‘The great disadvantage of the Mohr-Coulomb criterion 013 Terms of Use: http://asme.org/terms o t e i C a a t r s o r lus ssi- y 4 ory and ven h ory. sion ss he ell e ere f ys, his ted , the de- an- y, aw D sed. n d y, ap- by of ate. i- the ere 184 Yu: Advances in strength theories Appl Mech Rev vol 55, no 3, May 2002 Downl present is the lack of indication of behavior in the directi of the intermediate principal stress. Further developmen Mohr-Coulomb in this direction would be most interesting Some international symposia were held, the purposes which were to allow a comparison to be made of vario mathematical models of mechanical behavior of soils@339#. The introduction of a spherical end cap to the Druck Prager criterion was made by Druckeret al @550# to control the plastic volumetric change or dilation of so under complex stress state. Since then, a specific Cam model was suggested by Roscoeet al @553#. The Cam Clay model and critical state soil mechanics had been develo by the research group at Cambridge Univers @150,151,553,559,628,629#. The cap model had been furthe modified and refined by DiMaggioet al @631,632#, Farque- Chang@637# et al. Critical state concept gained widespre recognition as a framework to the understanding of the havior of soils, eg, Atkinson and Branoby@633#, Atkingson @634#, Wood@151#, and Ortigao@638#. The critical state con- cept was applied also to rock by Gerogiannopoulos Brown @386# and to concrete@31#. The cyclic behavior of soil under complex stress w studied by many researchers. A single-surface yield func with seven-parameter for geomaterials was proposed Ehlers@626#. The multisurfaces theory was originally intro duced by Mroz@639# and Iwan@640# and applied to two- surfaces or three-surfaces model by Krieg@641#, Dafalias- Popov @478#, Prevost@642,643#, Mroz et al @568,576,635#, Hashiguchi @147,616#, Shen @644#, Hirai @646#, de Boer @505#, Simo et al @647#, Zheng @649# et al. A generalized nonassociative multisurface approach for granular mate was given by Pan@648#. The concept of the bounding surfac was proposed by Dafalias and Popov@478# in metal plastic- ity, and applied to soil plasticity by Mroz, Norris, and Zien kiewicz @568,576,635#, as well as Dafalias and Herrman @581# and Borjaet al @606#. Strength theory is also generalized to act as rigid-pla and elasto-plastic models in RS~reinforced soils!. Some cri- teria for RS were proposed, such as Sawicki@651#, Micha- lowski and Zhao~RS with randomly distributed short fiber! @613#. A global yield surface considering thes1 ands3 was given by Sawicki. The summary of yield conditions for R and its applications in RS structures was presented in S icki recently @618#. The joint failure criterion@437# and the Mohr-Coulomb failure criterion were adopted as the yield criterion of s and interface in research for dynamic soil structure inter tion system@595#. A new interface cap model was recent developed by Lourenco-Rots@650# that is bounded by a composite yield surface that includes tension, shear and c pression failure as follows F5cnnsm 2 1cns1csst8 25s0 (66) 6.4 Failure criteria for iron Studies of the fracture of iron date back to the work of Co and Robertson in 1911~thick-walled tubes subjected to inte nal pressure and compression! @207#, Ros and Eichinger in oaded From: http://appliedmechanicsreviews.asmedigitalcollection.asme.org n of .’’ of us
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