Role of failure modes on energy absorption in unidirectional PMC tubes

The primary focus of this investigation was to study the effect of failure modes on key energy absorption parameters including the initial peak load ( P-peak), the drop in the peak load and the sustained crushing load (P-avg.) in the crushing process of unidirectional polymer matrix composite (PMC) t ubes under quasi-static conditions. The failure modes of interest are the a xial cracks, the transverse cracks and delamination. The roles of initiator s with different radii and external constraints were carefully analyzed in the context of primary failure modes using a real time image acquisition sy stem. The results for fiberglass/polyester tubes showed that the failure mo des play a critical role on the load-deflection (P-3) response of the tubes and their corresponding specific energy absorption (SEA). In addition, it was possible to control the failure modes for better crushing performance b y using external constraints combined with initiators.