五模点阵环状结构对碰撞冲击弹性波的调控试验研究

Experimental Study on the Regulation of Pentamode Lattice Ring Structure on Impact Elastic Wave

为研究五模点阵环状结构对碰撞冲击弹性波的调控效果,采用增材制造技术设计制作了3个五模点阵环状结构试验模型,通过冲击试验发现,试验模型内环迎冲面应变峰值均小于背冲面,这与传统环状结构有明显不同。此外,对比3个试验模型的调控效果发现,较小的胞元壁厚和胞元无配重有利于提升五模点阵环状结构对冲击弹性波的调控效果。进一步通过仿真发现,相较于等质量均质圆环,五模点阵环状结构可使迎冲面应力峰值最高降低76.3%,并将冲击波向两侧“疏导”,从而表现出显著的绕射效果。通过计算五模点阵胞元的频散曲线,获得了胞元主方向的群速度大小,在此基础上发现,胞元群速度各向异性对冲击弹性波的调控效果有明显影响,群速度各向异性越大,对冲击弹性波的调控效果越好。相关结论可以为潜艇结构抗冲击防护提供一定参考。

The mainly research is the regulation effect of pentamode lattice ring structure on impact elastic wave,three differ-ent pentamode lattice ring structure are designed and made as test models.Through impact test,it is found that the peak strain on the frontal surface of the inner ring is smaller than that on the backflush surface,which is obviously different from the traditional ring structure.In addition,by comparing the regulation effects of the three test models,it is found that smaller cell wall thickness and no cell additional weight are conducive to improve the regulation effect of the pentamode lattice ring structure on impact elastic wave.Further through simulation,it is found that compared with the homogeneous ring with equal mass,the pentamode lattice ring structure can reduce the peak stress of the frontal surface by 76.3%at most,and"dredge"the impact wave to both sides,thus show-ing a significant diffraction effect.By calculating the dispersion curve of the pentamode lattice cell,the group velocity in the main di-rection of the cell is obtained.The group velocity anisotropy of cells has a significant effect on the regulation effect of impact elastic wave.The greater the group velocity anisotropy,the better the regulation effect of shock elastic wave.The relevant conclusions can provide some reference for the anti impact protection of submarine structures.