Polymer, Vol.177, 84-90, 2019
Construction of master yield stress curves for polycarbonate: A coarse-grained molecular dynamics study
A coarse-grained particle model was developed for the simulation of deformations in polycarbonate. Coarse-grained molecular dynamics simulations of uniaxial and multiaxial deformations are carried out to determine the critical yield stress for various strain rates. From the calculated values, a master curve of the yield stress as a function of the strain rate is built at 300 K. It is found that the predicted results and experimental values are aligned on the same curve and can be described by a simple Cowper-Symonds relation. Furthermore, using the Williams, Landel and Ferry equation, a master curve is built to predict the yield stress at finite temperatures. By investigating additional deformation modes, two supplementary master curves are built at 300 K: one for the void nucleation and one for the shear yielding.
Keywords:Polycarbonate;Molecular dynamics;Coarse-grained particle;Deformations;Multiaxial loading;Yield stress;Strain rate