爆炸荷载作用下土埋圆柱壳动力屈曲分析

On dynamic buckling of cylindrical shell in soil subjected to blast loads

为研究爆炸动载作用下土中圆柱壳结构的动力稳定特性,依据爆炸动载作用下土埋圆柱壳的受力特征,建立了考虑土与圆柱壳相互作用的土弹簧-柱壳计算模型,应用非线性有限元方法进行了数值计算。在圆柱壳结构动力屈曲过程数值分析的基础上,运用B-R屈曲准则判定土埋圆柱壳在爆炸动载作用下的屈曲临界荷载,并重点讨论了土层变形性质对圆柱壳屈曲荷载的影响,得到了土中圆柱壳屈曲荷载和土体弹性常数K的定量关系。结果表明,屈曲荷载随土体弹性常数的增大而非线性增大。

To investigate the dynamic stability of cylindrical shell in shallow soil, the calculation model of soil spring-shell interaction was established based on the stress characteristic of the shell subjected to blast loads. The nonlinear FEM method was utilized to solve the structural dynamic responses. The B-R buck- ling rule was applied to determining the critical buckling load following the numerical simulation of the shell buckling progress. The influence of the soil layer deformation on the structural buckling load was an- alyzed in detail. The quantitative relationship between the buckling load of the structure and the elastic modulus of the soil was obtained. The results indicate that the structural buckling load increases nonlinear- ly with the soil elastic modulus.