IMPACT ENERGY AND DAMAGE BEHAVIOR OF HYBRID COMPOSITE STRUCTURES UNDER HIGH VELOCITY IMPACT

Abstract

Impact absorption energy together with the material damage of hybrid composite structure under high velocity impact was investigated. The hybrid composite structure studied in this work consists of six-layer, namely S2-glass-1, CMC, EPDM rubber, Al7039, Al-foam and S2-glass-2. A three-dimensional finite element simulation was conducted based on a progressive damage model using the commercial code program, LS-DYNA. In order to simulate the sufficient deformations and fractures, an extremely high velocity (5,000 m/s) was applied as impact loading to the hybrid composite structure. The damage parameter in continuum damage mechanics determined by the reduction of stiffness, and also the absorbed energy were calculated to analysis the local fracture of the hybrid composite structure. Results of finite element analyses revealed that S2-glass showed a wide range of damage and local delamination; CMC and aluminum foam revealed a narrow band of damage. It is therefore suggested that the progressive damage model was appropriate to simulate quantitatively the level of damage of hybrid composite structure under such high velocity impact.