9780072837032, Chapter 6, Problem 15PE

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Chapter 6, Problem 15PE Problem Create the Axiomatic Design equation (Eq. 6.1) for the portable syringe solution 2 described in Sec. 6.6.2, identifying all FRs and DPs. Classify the design based on the design matrix, [A ]. Eq. 6.1 (FR) Sec. 6.6.2 Syringe Design Concept 1- Concept 1 uses a hand pump (like with a blood pressure cuff) to excite the liquid. The user would insert a sharp, pointed tool to penetrate the muscle tissue, gaining access for the medication. The medicine would be allowed to flow through a rigid tube into the muscle area. No special positioning method is considered with this concept. Syringe Design Concept 2- Concept 2 is similar except a piston and cylinder arrangement would replace the pump for the first two functions. A shearing tool for cutting the skin and muscle tissue is used in place of the pointed tool. Flexible tube is used to convey the medication instead of a rigid tube. A strap and cuff arrangement is used for positioning. The number of possible combinations is quite large. For the example given here there are 4 X combinations, clearly too many to follow up in detail. Some may be clearly infeasible or impractical (e.g., radiating the medicine). Care should be taken not to make this judgment too hurriedly. Also, realize that some concepts will satisfy more than one subproblem. Likewise, some subproblems are coupled, not This means that their solutions can be evaluated only in conjunction with the solutions to other subproblems. The concept generation phase is usually considered successful with many fewer concepts to consider. Do not rush into evaluation of design concepts. Outstanding designs often evolve out of several iterations of combining concept fragments from the morphological chart and working them into an integrated solution. This is a place where a smoothly functioning team pays off. Although design concepts are quite abstract at this stage, it often is very helpful to utilize rough sketches. Sketches help us associate function with form, and they aid with our short- term memory as we work to assemble the pieces of a design. Moreover, sketches in a design notebook are an excellent way of documenting the development of a product for patent purposes. Step-by-step solution Step of 1 Students are asked to write out the Design Matrix, [A], and identifiy the function requirements (FRs) and design paramaters (DPs) as defined by Axiomatic Design for the second portable syringe design described in Section 6.6.2. In the design equation below, the term HE stands for human energy and KE for kinetic energy FR1 = Convert HE to KE = Liquid FR2 = Transfer KE to liquid DP2 = Piston and cylinder FR3 = Position liquid near muscle = DP3 = Shearing tool FR4 = Pierce muscle DP4 = Flexible tubing } FR5 = Guide liquid flow into muscle DP5 = Strap & cuff Recall that the design equation is defined as follows: = sothat - A, For this syringe design, the matrix tells us that FR1 FR3 = FR4 = FR5 = In the language of Axiomatic Design the design matrix [A] is coupled. As shown by the equations, you can not fulfill all the function requirements by setting the value of an individual design parameter independent of the impact on other function requirements. For example, FR1 can fulfilled by setting the value of DP2, but the value of DP2 also influences the fulfillment of FR2 and FR3. The current design is such that FR4 is the only function that can be fulfilled by an independent decision about DP3. For example, FR1relies on a single DP but links not only to but to both FR2 and FR3 making all three DPs So that the design process can proceed separately from the rest of the systems design. FR5can be fulfilled by setting two other parameters at the same time, giving it a kind of separation from the system. However, since two design parameters affect the same function requirement it does not strictly follow the form of functional independence.