Case study 13 



Process Simulation and Modeling 





|§i Injection 







Results of a computer simulation of a liquid molding process for manufacturing higfi strength polymer com- 

 posite automotive body panels. The simulation shows how the liquid polymer is injected into the mold and 

 predicts the flow front position as a function of time. The results of the simulation are used to better under- 

 stand the design of a particular mold and part and to select polymers and preplaced fiber preforms. 



In the future, one of the keys to optimizing new 

 product designs and manufacturing processes 

 will be the ability to model and simulate produc- 

 tion methods using advanced computer hardware 

 and software. Today, the development of many 

 products, including those that require castings. 

 forgings and injection-molded parts, for exam- 

 ple, typically require lengthy and expensive pro- 

 totyping and experimentation to refine details of 

 the product design, tooling, and manufacturing 

 parameters. The use of computerized process 

 modeling and simulation will eliminate much of 

 this prototyping and dramatically reduce product 

 development times and costs. 



The traditional approach of using experimenta- 

 tion and prototyping to refine production pro- 

 cesses is indicative of the fact that manufactur- 

 ing practices have historically been based as 



much on "art" as on sound scientific understand- 

 ing of the processes involved. This is changing 

 rapidly as a result of research to achieve better 

 theoretical understanding and predictability of 

 specific processes and materials and their effect 

 on product performance and costs. Improved 

 theoretical frameworks are advancing progress 

 on a wide range of manufacturing applications, 

 processes and materials, including stamping and 

 forming, machining, powder compaction pro- 

 cesses and even assembly of parts. 



Process modeling and simulation is being pur- 

 sued by a number of organizations, including the 

 National Institute of Standards and Technology 

 (NIST). For example, as part of a cooperative 

 agreement with Ford. Chrysler and General 

 Motors. NIST is conducting research into the use 

 of polymer composites for structural applications 



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