Matrix crack initiation and progression in composite laminates subjected to bending and extension (Q1302798)

This paper experimentally investigates the degraded properties of composite laminates with different ply angles and varying stacking sequences. Some experimental data are presented concerning the matrix crack initiation and the progression in glass/epoxy laminates under bending and extension. The test results are given for degraded elastic properties in extension, and for the reduced stiffness in bending. The crack densities are presented as functions of the energy release rate and applied strains. The authors illustrate the stress-strain behavior of the tested cross-ply laminates, and compare the experimental results with analytical reuslts calculated from the two-dimensional Kirchhoff theory of laminates. Though the results cannot be generally applicable, the paper is a valuable experimental contribution to the study of macromechanical behavior of composite laminates.