Elasto-viscoplastic analysis for negative through-the-thickness Poisson's ratio of woven laminate composites based on homogenization theory

摘要

In this study, the negative through-the-thickness Poisson's ratios of [+/-theta] woven laminates were analyzed based on the homogenization theory for elasto-viscoplastic materials. A [+/-theta] woven laminate model with the fiber bundle cross angle +/-theta was considered and its diamond-shaped domain of analysis was defined. The elasto-viscoplastic homogenization analysis was performed to investigate the negativity of the through-the-thickness Poisson's ratios for the [+/-theta carbon fiber/epoxy and glass fiber/epoxy woven laminates. The through-the-thickness Poisson's ratio of the [+/- 30 degrees] carbon fiber/epoxy woven laminate was negative in both the elastic and viscoplastic regions. However, that of the [+/- 30 degrees] glass fiber/epoxy woven laminate was positive in the elastic region but became negative in the viscoplastic region. The negative through-the-thickness Poisson's ratios of the [+/- 30 degrees] woven laminates were caused by the compressive stress with respect to the in-plane direction and the viscoplastic deformation of the matrix. (C) 2017 Elsevier Ltd. All rights reserved.