A Computer Model for Progressive Failure Analysis of Thick Composite Plates

Abstract

A computing model for the progressive failure analysis of thick composite plates is developed. Since the model is for thick plates, it is based on a higher-order zigzag laminate theory so that the interlaminar continuity conditions of transverse shear stress and the shear free surface conditions are satisfied. The elastic stress analysis is used as an initial failure load. Then, the load is increased step by step, the stresses are evaluated, and the appropriate failure criterion is applied to inspect possible failure. When failure is initiated, the material properties are modified according to the selected failure mode using a non-zero stiffness degradation factor. Thereafter, the modified Newton-Raphson iteration is carried out until convergence is reached. This analysis is repeated for each load increment until the final failure occurs and the ultimate strength is determined. A numerical example of the failure progress of a simply supported plate is investigated. The present method yields a reasonable agreement with three dimensional finite element solutions.