An Experimental Method for Compressive Properties of Laminated Composites at High Rates of Loading

Abstract

Dynamic responses of composite materials are characterized for ballistic engineering applications. An experimental method has been developed to investigate the dynamic effects on material behavior at a strain rate typically found during the launching of a projectile. An air-gun system and a test fixture with a designed crashing mechanism are used to simulate a loading condition resulting from gun firing. Methods of data acquisition and reduction have also been developed using a streak camera and a film digitization technique. The system is calibrated and verified by testing aluminum samples, and fairly good results are obtained. Finally, polymer composite laminates with lay-up constructions of interest are tested. Strain rate effects on the compressive strength are determined at strain rates of 10-100 in/sec. The failure mechanism of composite laminates is also investigated, which provides an understanding of the strengthening mechanism of composites subjected to impact.

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