Shape Optimization of Sheet Metal Structures against Crash

Abstract : A theoretical and experimental study was undertaken into the crushing behavior of axially compressed short thin-walled open-section columns. The effect of initial geometry of panels as well as distribution and magnitude of shape imperfections on the efficiency of energy absorption was examined. Results of model test on 0.1mm thick aluminum foil specimens have shown that the panels collapsing in the symmetric and asymmetric deformation mode provide respectively, upper and lower bound for the energy absorbed in any other buckling mode. In both of the extreme cases, the crush response of the panel was predicted theoretically with a reasonable accuracy. It is shown that an optimum design of columns against crush can be achieved by introducing a beneficial geometric imperfections of a specified magnitude shape so that the structure will be forced to collapse in the most energy efficient deformation mode.