Energy absorption of bio-inspired multi-cell CFRP and aluminum square tubes

Abstract

Abstract This paper aims to investigate the energy absorption of the bio-inspired multi-cell carbon fiber reinforced plastic (CFRP) and aluminum (Al) square tubes under the quasi-static axial crushing. Single-cell, double-cell and triple-cell CFRP and Al square tubes were bio-inspired designed and fabricated. The quasi-static compression tests were conducted to explore the force-displacement response, failure process, crashworthiness characteristics and the corresponding energy absorption mechanisms. The stable progressive folding with inextensional mode were found in Al tubes and progressive end crushing for CFRP tubes. The test results showed that the peak force, the mean crush force and the specific energy absorption (SEA) of CFRP tubes were higher than those of the Al tubes with the same cells. The cell number was sensitive to the crashworthiness characteristics for both CFRP and Al tubes. The specific energy absorption of the double-cell and the triple-cell CFRP tubes increased by approximately 17.0% and 2.4%, respectively, compared with that of the single-cell one, whilst 3.1% and 27.7%, respectively, for Al specimens. It was notable that the double-cell CFRP tubes exhibited the maximum SEA value of 66.31 J/g in the CFRP specimens, whereas the triple-cell Al tubes exhibited the maximum SEA value of 14.80 J/g in the Al specimens, which were attributable to the different interaction effect occurred in the connecting region.