Free Edge Stress Analysis of Unidirectional CFRP Laminates Based on a Homogenization Theory for Time-Dependent Composites

摘要

In this study, distributions of microscopic stress at free edges of unidirectional carbon fiber-reinforced plastic laminates (CFRP laminates) are analyzed three-dimensionally, based on a homogenization theory for time-dependent composites. For this, the homogenization theory is reconstructed for free edge problems using a traction-free boundary condition. Then, an analysis domain is reduced using the point-symmetry of the internal structure of the unidirectional CFRP laminate. Moreover, the substructure method is newly introduced into the theory to reduce the computational costs required for the analysis. The present method is then applied to the elastic-viscoplastic microscopic stress analysis at free edges of unidirectional carbon fiber/epoxy laminates subjected to an in-plane uniaxial tensile load. It is shown that complex microscopic stress distributions occur in the vicinity of the free edge, especially around fiber/matrix interface regions.