THERMOVISCOELASTIC CALCULATION OF RESIDUAL-STRESSES AND RESIDUAL SHAPES OF INJECTION MOLDED PARTS

The present paper describes a three-dimensional finite element method for calculating thermoviscoelastic stresses generated during cooling of injection molded parts. The initial temperature field corresponds to the end of the filling stage. The fully time-dependent algorithm is based on the calculation of the elastic response at every time step. The time-temperature equivalence is assumed for the non-isothermal behavior. At the end of the calculation, one obtains the residual stresses and the shape of molded parts at room temperature. The method is illustrated by means of four examples.