Abstract
The energy absorbing performance of glass fiber reinforced thermoplastics was evaluated by progressive crushing tests with the Split Hopkinson Pressure Bar (SHPB) apparatus. Two types of specimens, one was injection molded glass long fiber reinforced polyamide 66 (GF/PA66), the other was twill weave glass fiber reinforced polyamide 6 (GF/PA6), were prepared as specimens. As for injection molded plates of the GF/PA66, it was investigated the influence of the fiber orientation on the impact mechanical behavior of the test specimen cut out from the different position of the plate. Also, the impact behavior of injection molded the GF/PA66 plates and that of twill weave GF/PA6 laminates were compared in order to investigate the influence of the variation of reinforcing types. As a result of the progressive crushing tests at -30, 23, 90°C, it is revealed that the energy absorbing performance has no temperature dependency regardless of the fiber orientation and the reinforcing types. The reason that the SEA of the GF/PA66 increases with the mechanical properties was discussed from the comparison of the specific energy absorption (SEA) and the compressive strength. In the comparison of injection molded the GF/PA66 and the GF/PA6 laminates, the specimens were reinforced by the different mechanisms; therefore, it seems that influence of mechanical properties on the SEA is not critical because those fracture modes are different.
