Centrifuge experiment and numerical study on the dynamic response of air-backed plate to underwater explosion

This work compares experimental and numerical results concerning the elastic dynamic response of air-backed plate to underwater explosion. Experiments were performed in a centrifuge, both the shock loadings and structure responses were tested, and the bubble oscillation considering centrifugal force was predicted with Geer and Hunter model. The experimental and numerical results illustrates that the centrifugal force have no effect on shockwave for the short duration of action, and with the increase of centrifugal force, the bubble pulse motion cycle, maximum bubble radius, and peak pressure of bubble pulse decreased; both the peak of high-frequency and low-frequency response of the plate decline slightly when alpha damping rising ,the high-frequency response mode almost have no change with different alpha damping ,while, the low-frequency response tends to be an obvious oscillation waveform when the alpha damping is too low; although the difference of the peak acceleration owing to shock wave and bubble reaches to tens of times, the strain responses caused by the two factors are very close, which enucleates that the train response is related to shock energy and has a higher sensitivity to time accumulation; both the peak acceleration and peak strain due to the shock wave remain steady and the two kinds of response by bubble pulse decrease with the centrifugal force increasing; when the target position is more close to the area that the shock wave vertically impact ,the linear correlation between peak velocity and shock factor is much better. Key words: underwater explosion; centrifugal effect; FEM.