The Study Of Dynamic Response Of Double-layer Shell Under The High-speed Pulse Impact

Impact is always need to be considered while designing and analyzing shell in engineering, so it has significant practicing meaning to study the plastic dynamic issue of the double-layers shell model under the high-speed pulse impact.In this paper, an experiment of pulse impacting on LY12 aluminum alloy under the high-speed has been designed and implemented. The experimental data has been collected and analyzed. The material characteristic of the LY12 aluminum alloy under the high-speed pulse impact by 52m/s or 32m/s have been obtained.By introducing two target's rigidity and two bullet's initial velocity 52m/s and 32m/s, the imitating calculation has been made for the plastic dynamic issue of the double-layers shell model under the high-speed pulse impacting. The Lagrange analyzer of explicit integral method of dynamic Limited Elements is applied to the calculation. The result presents the relations among the structural displacement, speed, acceleration, stress, strain and time of the exterior shell, the middle shell and the inside solid of double-layers shell under the impact in the axis-direction, and shows the evolvement process of structure of double-layers shell under the high-speed impact in the axis-direction.After analyzing the prototype's structural, and considering the theory of energy's dissipation of material under the high-speed pulse impact, the optimized design of prototype's structural has been designed to satisfy the defending inside solid and economize material. Three structure models have been made and the imitating calculation of impacting on two kinds of rigidity's target has been implemented for each of them under two high-speed pulse impacts in the axis-direction. The stress and strain value and their distribution of the exterior shell, the middle shell and the inside solid under every time, achieve the relations among the structural displacement, speed, acceleration and time of the inside solid of three double-layers shell under the impact in the axis-direction have been obtained. And the dynamic developmental process of double-layers shell model under four exterior loads has been gained.By analyzing and contrasting the outcome of four species numerical value imitation, the structure 3 which has interlaced setting's bracket has been considered to be the best configuration of double-layers shell model for inside solid's safety under lower impact load.Differentiating other structures, Structure 4 is devised that middle shell head is hung in the air, bracket support among exterior shell and middle shell, exterior shell's thickness is decreased, the displacement's space of middle shell and inside solid is augmented, bracket is interlaced set, the length of middle shell's bracket is shortened. Under higher impact load, Structure 4 is the better than others for inside solid's safety under higher impact load.In the paper, theoretical basic work has been provided for the future improvement of the optimization for double-layers shell model.