On the axial propagation of kink bands in fiber composites : Part ii analysis

A new micromechanical model is presented to simulate the steady!state axial propagation of kink bands investigated experimentally in the accompanying paper "Part I#[ The _bers are in a hexagonal array and are assumed to be isotropic and linearly elastic\ while the matrix is modeled as an elastic!powerlaw viscoplastic solid[ Matrix properties for the model are determined from shear tests on the composite and compression tests on neat PEEK[ The model is used to predict the propagation stress "sP# of the AS3:PEEK composite and to investigate the sensitivity of sP to band inclination\ matrix properties\ and loading rate[ A simple model recently reported in the literature is calibrated to the current material system and compared with the present experimental data and model predictions[ The micromechanical model is found to predict the propagation stress reasonably well and to capture the rate dependence of the composite[ The simple model is found to capture the trends of the behavior[ 0887 Elsevier Science Ltd[ All rights reserved[