Numerical study of cyclic accommodation at the lamellar scale of a viscoelastic semi-crystalline polymer

Viscoelastic materials like semi-crystalline polymers raise the issue of defining and understanding the stabilized cycle from which the mechanical parameters of fatigue life criteria should be calculated. Facing the lack of direct experimental access at the nano-scale in these polymers, full-field Finite Element simulations were conducted for an idealized periodic crystalline-amorphous lamellar stack and coupled to stress-field analysis tools (global and phase averages, variance). Local heterogeneity in the amorphous phase (stress fluctuations and states) is analyzed. Average stress–strain responses of the full lamellar stack and of the phases are studied to discuss connections between global and local cyclic stabilizations.