Analysis of discrete-source damage progression in a tensile stiffened composite panel

Abstract

This paper demonstrates the progressive failure analysis capability in NASA Langley's COMET-AR finite element analysis code on a large-scale built-up composite structure. A large-scale five stringer composite panel with a 7-in. long discrete source damage was analyzed from initial loading to final failure including the geometric and material nonlinearities. Predictions using different mesh sizes, different saw cut modeling approaches, and different failure criteria were performed and assessed. All failure predictions have a reasonably good correlation with the test result. Introduction For composite material to be successfully used in primary aircraft structures such as wings and fuselages, one of the design requirements is a two-bay crack damage tolerance capability. The two-bay crack, representing a discrete source damage caused by fragments from a failed engine, spans from one bay to the other bay and severs one stiffener. To meet the damage tolerance requirement, this two-bay dam...