蜂窝钢管约束混凝土靶的准静态球形空腔膨胀模型及其应用

Quasi-static Spherical Cavity Expansion Model of Cellular Steel-tube-confined-concrete Targets and Its Application

蜂窝钢管混凝土通过对混凝土施加约束提高混凝土的抗侵彻性能,建立刚性弹侵彻钢管约束混凝土靶的侵彻深度模型具有重要的理论意义和应用价值;而基于空腔膨胀理论建立工程模型是研究侵彻问题的常用方法之一.论文针对射弹侵彻蜂窝钢管钢管约束混凝土靶问题,考虑被打击单元钢管及其外围混凝土的综合约束作用,粉碎区混凝土采用Hoek-Brown(H-B)准则,建立了蜂窝钢管约束混凝土靶的准静态球形空腔膨胀模型和刚性弹侵彻深度预测公式,并基于相关侵彻试验分析了综合约束刚度对侵彻过程的影响.研究结果表明:蜂窝钢管约束混凝土靶不同于半无限混凝土靶,侵彻过程中的扩孔压力不为常数;综合约束刚度越大,扩孔压力越大;侵彻深度预测公式计算结果与文献侵彻试验吻合较好.论文成果为蜂窝钢管混凝土在防护结构中的应用奠定了基础.

Cellular steel-tube-confined-concrete improves the anti-penetration performance of concrete by restraining the concrete.It is of great theoretical significance and application value to establish the penetration depth model for steel-tube-confined-concrete(STCC)targets penetrated by rigid projectiles.The cavity expansion theory is one of the common methods to establish the engineering models for penetration problems.For the penetration problem of cellular STCC targets,aquasi-static spherical cavity expansion model is firstly developed on the basis of inclusion of the comprehensive confinement of steel tube and the peripheral concrete on the impacted cell as well as the assumption that failure behavior of concrete obeys the Hoek-Brown(H-B)criterion in the comminuted region;and then influences of the comprehensive confinement stiffness on the penetration process are analyzed on the basis of relevant penetration tests.The numerical results show that the radial stress of STCC targets on the cavity wall does not remain constant during the expansion process,which is different from those of infinite concrete targets;the pressure on cavity wall increases with the increase of the comprehensive confinement stiffness;and the predicted results of depth of penetration are in good agreement with the experimental ones in the literature.The results in this paper may lay a foundation for the application of cellular steel-tube-confined-concrete in the protective structures.