Comparison of Folding and Inversion Processes on Foam-filed and Empty Frusta

This approach studies energy absorption behavior of folding and inversion processes as two different mechanisms of energy absorber on of the capped-end frusta under the axial loading. For this purpose, some different specimens were prepared and tested to investigate the different deformation modes, values of the maximum force, average force and energy absorption by the structure. Based on the experimental results, it is concluded that the folding process is a mechanism of energy absorption with the highercapacity, comparing with the inversion process of metal capped-end frusta. Also, experiments affirm that in the all cases, the polyurethane foam-filler increases the specific absorbed energy by the structure during the both of inversion and folding processes on the cappedend frusta.