Simulation of thermomechanical processes in crystallizing polymer

Constitutive equations are developed to describe the interrelation between thermomechanical behavior and phase transitions in crystallizing polymers. A crystallizing polymer is considered as a two-component mixture of amorphous and crystalline structures, the fraction of which is defined by the degree of crystallinity. Numerical realization is performed using a variational method and a finite element procedure. The key feature of the calculation algorithm is reduction of a nonstationary problem to a sequence of stationary problems on a nonuniform time mesh. The validity of the proposed mathematical model is supported by the results of experiments performed to study the evolution of the stress-strain state for a disk-shaped polyamide 6 plate on crystallization.