An experimental study of the saturated impulse for metal plates under slamming

Abstract

Engineering structures can suffer severe local structural damage when subjected to extreme dynamic pulse loadings such as slamming impact. However, there is paucity of information on how the loading pulses affect the large plastic deformations. This paper presents information on an experimental investigation into the dynamic pressure pulse generated by slamming and the plastic response of metal plate. In our experiments, plates made of aluminum and steel alloy, were dropped from various heights ranging from 0.1 m to 1.3 m, onto the calm water in a tank. Based on the experimental results, the effects of structural material and water impact velocity on the slamming pressures pulse are investigated in detail. The results indicate that not only the peak pressure but also the pressure pulse duration play important roles in governing the dynamic response of the impacted structures. It is shown that the maximum strain and deflection at the plate center increase almost linearly with the drop height of the drop model. In view of the lack of previous experimental evidence for the saturation phenomenon of structures under slamming, we compared the dynamic response at the center of the plate with the experimentally measured slamming pressure under various drop heights, so that we have evidently verified the saturation phenomenon of flat plates for the first time under slamming in drop tests. It is also revealed that the dynamic response of the flat plates under slamming becomes more prone to the saturation phenomenon with the increase of drop height.