Structural Behavior of Composites with Progressive Fracture

Abstract

Structural characteristics such as natural frequencies and buckling loads with corresponding mode shapes were investigated during progressive fracture of mul tilayer, angle-plied polymer matrix composites. A computer program was used to generate the numerical results for overall mechanical response of damaged composites. Variations in structural characteristics as a function of the previously applied loading were studied. Results indicate that free-vibration and buckling stability properties were preserved throughout a significant proportion of the ultimate fracture load. For the cases studied, changes in structural behavior begin to occur after 70 percent of the ultimate fracture load had been applied. However, the individual nature of the structural change was rather varied depending on the laminate configuration, fiber orientation, and the boundary condi tions.