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

In this study, the negative through-the-thickness Poisson’s ratios of [±θ] woven laminates were analyzed based on the homogenization theory for elasto-viscoplastic materials. A [±θ] woven laminate model with the fiber bundle cross angle ±θ 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 [±θ] carbon fiber/epoxy and glass fiber/epoxy woven laminates. The through-the-thickness Poisson’s ratio of the [±30°] carbon fiber/epoxy woven laminate was negative in both the elastic and viscoplastic regions. However, that of the [±30°] 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°] woven laminates were caused by the compressive stress with respect to the in-plane direction and the viscoplastic deformation of the matrix.
ファイル公開：2020-10-01