| Description |
Crashworthiness is concerned with the safety of occupants and cargo during an impact. The most successful approach to crashworthiness is to incorporate a crush structure into the vehicle designed to progressively crush and absorb impact energy while protecting the safety cell and occupants from unacceptable forces and intrusion. Design for crashworthiness is a complex process in a field with a high level of ongoing research. An efficient method of design for crashworthiness can be visualized as a pyramid. The foundation level of the pyramid is concerned with materials and composite laminates, and involves testing of small test articles like tubes and flat coupons for material and laminate characterization. The intermediate levels of the pyramid are concerned with structural and geometric parameters, and involve testing of shaped components and subassemblies. Testing of the full-scale design occurs at the top level. This research focused on the testing of flat coupons, and therefore pertains to the foundation level of the pyramid. An improved test fixture was developed to more effectively measure the energy absorption of flat composite coupons. In connection with the improved test fixture, a draft ASTM standard was written for crush testing of flat composite coupons. The test fixture was used to investigate the effects of loading rate and laminate design. An pinned-base test configuration was investigated for replicating the effects of curvature on energy absorption and crush mode using flat test coupons. Finally, an analytical model was developed to predict delamination and the development of crushing in composite laminates, pursuant to a method of predicting energy absorption. These developments contribute to increased potential for use of composite materials in crash structures. |
