Experimental investigation of the crash energy absorption of 2.5D-braided thermoplastic composite tubes

Braided composites tubes have been reported to have a great potential in crash energy absorption applications. However, previous works were limited to thermoset braided composite tubes. In this study, we are interest in the crash energy absorption performance of 2.5D braided thermoplastic composite tubes. The sensitivity to materials, fiber orientation and geometry was investigated. Three crushing modes have observed. The splaying and progressive folding were reported for glass/polypropylene tubes and fragmentation mode was observed carbon/polyamide tubes. The last mode has the highest specific energy absorption of 61 kJ/kg. The progressive folding mode has higher specific energy absorption (36 kJ/kg) than the splaying mode. Moreover, the specific energy absorption increases with increasing braiding angle and decreasing length-to-diameter ratio, for glass/polypropylene tubes. On the opposite, the specific energy absorption deceases with braiding angle for carbon/polyamide tubes.