Energy absorbing characteristics of GF/Nylon tubes - effect of trigger geometry and testing speed on energy absorption

In this paper, compression tests in GF/Nylon6 tubes were performed to clarify the mechanism of the initial failure process and the characteristic of the energy absorption. It was found that all the specimens were crushed in a progressive crushing mode regardless of the trigger geometry, but that the specimens with an asymmetric trigger demonstrated to have a better energy absorbing characteristic than that with a symmetric one. The formation mechanism of the debris-wedge was examined through the step-wise morphology analysis. It was also found that changes in the trigger geometries affected the performance of the initial failure process which was characterized by the debris-wedge formation process. As for an effect of testing speed on the specific energy absorbing capability, the GF/Nylon6 tubes had small dependency of the testing speed in the range of our study comparing CF/PPEK tubes. From those results, it could be concluded that the GF/Nylon6 tubes are available to practical use.