Experimental studies on thin-walled grooved tubes under axial compression

We study experimentally the axial crushing behavior and crashworthiness characteristics of thin-walled steel tubes containing annular grooves. The grooves determine the positions of the folds and control the buckling mode of deformation. In the present work we aim to improve the uniformity of the load-displacement behavior and to predict the energy absorption capacity of the tubes. Grooves are cut circumferentially and alternately inside and outside the tubes at predetermined intervals. Quasi-static axial crushing tests are performed with different groove distances. Photographs are taken during axial buckling and the specimens after crushing are sectioned axially to carry out the measurements. The deformation modes and load-displacement curves are described and energy absorption and mean post-buckling load are determined. The convolutions are achieved by folding in an axisymmetric concertina mode about the circumferential grooves. The results show that the load-displacement curve and energy absorbed by the axial crushing of tubes can be controlled by the introduction of grooves with different distances.