Post-Crazing Stress Analysis of Glass-Epoxy Laminates

摘要

A glass-epoxy material known as Scotchply XP-250 was characterized. The material's various strengths and stiffnesses were determined in tension, compression, and shear. The three-rail fixture was used for the shear tests. A modified IITRI fixture was used for compression. Glass-epoxy laminates having the following layups were tested in tension. The stress-strain behavior in the pre- and post-crazing regions was predicted with a lamination program which employed the nonlinear ply shear curve. These predicted and test results were compared. A finite element program was written for obtaining stress analysis of laminated structures with stress concentrations. The program used a doubly-curved, isoparametric, thick-plate or thick-shell element. A number of example problems were solved. The finite element results were compared to test results for a tension coupon containing a hole.