Crashworthiness of Composite Fuselage Structures - Material Dynamic Properties, Phase 1

摘要

The use of composite materials for airframe structural applications is widespread in the commercial, business, and general aviation industries. Crashworthiness of metallic airframe structures investigations, using experiments at the coupon, subcomponent, and large-scale structural levels, and preliminary evaluations of analytical modeling of the dynamic impact event exist in open literature. The results of a limited number of dynamic and drop tests performed on fully composite fuselage structures indicated differences in the crush patterns, failure modes, stiffness, and other structural properties compared to traditional metallic fuselage structures. The differences observed between the composite and metallic structures under dynamic loads have often been attributed to the strain rate sensitivity of composites. An understanding of the strain rate effects at the materials level is necessary to facilitate a building-block approach for designing crashworthy airframe structures. In this study, the continuous fiber-reinforced composite material systems sensitivity to strain rates was investigated experimentally. The in-plane tension, compression, and shear properties of seven composite material systems were characterized at different strain rates. The details of the test methods, test data, and observations related to the strain rate sensitivity of the materials are presented in this report.