AbstractThe National Aeronautics and Space Administration (NASA) has sponsored research to evaluate an externally deployable composite honeycomb designed to attenuate loads in the event of a helicopter crash. The concept, designated the deployable energy absorber (DEA), is an expandable Kevlar honeycomb. The DEA incorporates a flexible hinge that allows the honeycomb to be stowed collapsed until needed during an emergency. Evaluation of the DEA began with material characterization of the Kevlar-129 fabric/epoxy and ended with a full-scale crash test of a retrofitted MD-500 helicopter. During each evaluation phase, finite-element (FE) models of the test articles were developed, and simulations were performed using the dynamic FE code LS-DYNA. This paper focuses on simulations of two full-scale impact tests involving the DEA: a mass simulator and a DEA-retrofitted MD-500 helicopter. Isotropic (Mat 24) and composite (Mat 58) material models that were assigned to DEA shell elements were compared. Based on sim...