Modeling and Simulation of Carbon Composite Blast Behavior

The design of new generation aircraft is driven by the vastly increased fuel cost and the resultant imperative for greater fuel efficiency. Carbon fiber composites have been used in aircraft structures to lower weight due to their superior stiffness and strength-to-weight properties. However, carbon composite material behavior under dynamic ballistic and blast loading conditions is relatively unknown. For aviation safety consideration, a computational constitutive model has been used to characterize the progressive failure behavior of carbon laminated composite plates subjected to ballistic and blast loading conditions. Using a meso-mechanics approach, a laminated composite is represented by a selected number of representative unidirectional layers with proper layup configurations. The damage progression in a unidirectional layer is assumed to be governed by a set of strain-rate dependent layer progressive failure criteria using the continuum damage mechanics approach. The composite failure model has been successfully implemented within LS-DYNA as a user-defined material subroutine. In this study, a series of experimental, close-in shock-hole blast tests on carbon composite panels, were simulated using the LS-DYNA-ALE method integrated with the ARL progressive failure composite model, which include strain rate effects on damage and fracture. The computational constitutive model has been validated to characterize the progressive failure behavior in carbon laminates subjected to close-in blast loading conditions with reasonable accuracy. The availability of this modeling tool will greatly facilitate the development of carbon composite structures with enhanced ballistic and blast survivability1.