摘要
为进一步探讨弹体对岩石靶体的侵彻作用机理,基于对岩石材料的八面体剪应力随平均主应力非线性增加特性的考虑,通过增加平均主应力的非线性项对双剪统一强度准则进行改进。分别采用双剪统一强度理论和改进的双剪强度理论作为岩石材料的强度准则,建立了弹体垂直侵彻岩石靶体的动力球形空腔膨胀可压缩弹塑性侵彻模型,提出了考虑侵彻过程中弹头法向和切向摩擦阻力影响的弹体垂直侵彻岩石靶体的阻力计算公式,进而求得了弹体垂直侵彻岩石靶体的深度。理论分析模型的计算结果与常用侵彻经验公式的计算结果以及野外花岗岩侵彻试验数据的对比分析表明:基于改进双剪强度理论所建立的理论分析模型的计算结果与试验数据最为接近,其主要原因是在靶体强度准则中考虑了八面体剪应力的影响。
In order further to investigate the penetration mechanism of projectiles into a rock target, the property of nonlinear dependence of the octahedral shear stress on an average principal stress state was considered, and the traditional Twin Shear United Strength criterion was improved by adding the nonlinear item of the average principal stress state. The dynamic Spherical Cavity Expansion compressive elasto-plastic penetration model of the rock target is established by the basis of Twin Shear United Strength Theory and Improved Twin Shear Strength Theory respectively, and the resistance calculation expression of the projectile during normal penetration is proposed with the consideration of both vertical and shear friction of projectiles, the normal penetration depth of the projectile into the rock target is obtained. By comparison of the calculated results of theoretical model and classical empirical penetration formula with the data of field penetration tests on granite targets, it indicates that the calculated results based on the Improved Twin Shear Strength Theory are most close to the test data, the main reason of which lies in the consideration of the octahedral shear stress in the strength criterion of the target material.
出处
《工程力学》
EI
CSCD
北大核心
2009年第8期216-222,共7页
Engineering Mechanics
基金
国家自然科学基金项目(50525825,50638030)
国防基础科研项目(A1420060186)
江苏省自然科学基金创新学者攀登项目(BK2008002)
关键词
侵彻深度
岩石靶体
球形空腔膨胀理论
双剪统一强度理论
八面体剪应力
penetration depth
rock target
spherical cavity expansion theory
twin shear united strength theory
octahedral shear stress
