Experimental and theoretical study on large ductile transverse deformations of rectangular plates subjected to shock load due to gas mixture detonation

摘要

The main purpose of this study is to show that metal plate forming by direct application of gas mixture detonation loads can be considered as an alternative high-velocity forming method for structures instead of a conventional one. Therefore, in this investigation, a series of experimental tests have been conducted on aluminium alloy and mild steel plates with different thicknesses to examine large ductile transverse deformations of rectangular plates with clamped edge conditions subjected to gas mixture detonation loading. The main aim of the experimental section is to investigate the effects of predetonation pressures of acetylene (C2H2) and oxygen (O-2) gasses and different mixture ratios on the dynamic response of specimens. The permanent deflections of plates have widely varied from 21.66 up to 56.31mm. In theoretical analysis, according to an upper bound solution and energy method, theoretical models have been presented by assuming a zero-order Bessel function of the first kind in the x and y directions for a transverse displacement profile to predict permanent deflections. To account for material strain rate sensitivity, a Cowper-Symonds model has been used, whereas the material coefficients of this equation are constant values or functions of plate thickness. A comparison of the present models with Jones' theoretical model shows that a good agreement with experimental results can be obtained when constant values are used for material coefficients in the Cowper-Symonds equation.