Axial crushing behavior of two-dimensional braided composite tubes-An experimental study

Braided composite tubular structures are being considered as a new type of energy absorbing components to improve vehicle crashworthiness. In this study, the crushing behavior of composite tubes manufactured by two-dimensional braiding method is investigated experimentally. Composite tubes are made of polyester fiber/epoxy. First, three types of composite tubes with the same diameter are weaved by a 16-carrier braiding machine, namely one-layer open-mesh (1L-OM) specimen, one-layer close-mesh (1L-CM) specimen, and two-layer (2L) specimen. The braiding angle at 1L-OM and 1L-CM are 65° and 75°, respectively. Then, all specimens are impregnated with EPL-1012 epoxy resin by hand and cured for seven days and post-cured for 2h at 90°C. Composite tubes are tested under the quasi-static axial crushing using universal testing machine. The load-displacement curves of above specimens are compared. Results show that the maximum load of 1L-OM specimen is more than the 1L-CM. By increasing the number of braiding layers from one to two, the maximum load increases up to two times. Also, braiding angle has significant effect on the axial stiffness of specimens.

Keywords:

Braiding , Axial crushing , Composite tube.