NUMERICAL-SIMULATION OF POLYMER FORGING - HOW TO DETERMINE THE RHEOLOGICAL COEFFICIENTS

Previous work has shown that numerical simulation does not provide a c orrect description of compression experiments if the theology of the p olymer in the solid state is deduced fr om tensile tests. Therefore, a new method is proposed for the determination of the coefficients of G 'sell's constitutive equation, in order to simulate the forging proces s. It also gives access to a parameter characterizing the friction con ditions between the polymer and the tool. It is based on isothermal co mpression of polymer cylinders with an appropriate geometry and on its complete interpretation by means of computer simulation using the fin ite element code FORGE2. This original procedure is applied to polyoxy methylene.