Elastic-plastic analyses of symmetric angle-ply carbon/epoxy laminates based on the rule of mixtures

This paper presents elastic-plastic analyses of symmetric angle-ply carbon/epoxy laminated composites subjected to a uniform axial strain through the application of constitutive equations based on the rule of mixtures. It is assumed that the matrix is elastic-perfectly plastic and the fibers are elastic. A finite element method is used to obtain numerical solutions for symmetric 45° angle-ply carbon/epoxy laminates. The stress distributions in the section of laminated composites, especially interlaminar stress distributions near the free edge, and the growth process of plastic regions are investigated. Numerical solutions for initial yield stresses and final failure stresses of laminates with different numbers of stacking layers are compared with experimental data. On the basis of this comparison, we propose a failure mode for laminated composites.