混凝土基于孔隙演化的本构模型及高速侵彻破坏机理研究

According to the problems of present research on concrete that the relationship between macro-scale constitutive model and meso-scale features is not clear under strong impact, and the failure mechanism of concrete target is not completely clear under projectile high velocity penetration, systemic studies will be made in the program. Based on the porous material deformation model and crack propagation criteria, the pore evolution equations of multi-stage for concrete will be established. Assembling the pore evolution equation and the equation of state for matrix, the equation of state considering porous compaction for multi-stage will be established; Based on the representative volume element of hollow sphere and the upper bound approach, the strength evolution equations of concrete will be established; Based on the half-projectile technology and high velocity normal penetration expriment with small size projectile, the inner damage shape of concrete target will be obtained; Based on the computing platform of dynamic finite element software, the program containing fluid-elastic-plastic model(FEPM) considering pore evolution will be designed. Based on the FEPM considering pore evolution and the evolution laws of plastic/brittle cracks, the failure mechanism of concrete for penetration, scabbing and perforation will be revealed. The study will gave theoretical support for engineering defense technology and earth penetration weapon design.

本项目针对强冲击下混凝土宏观本构模型与细观特性关联机制不清，弹体高速侵彻时混凝土靶体破坏机理尚不十分明确等问题拟开展系统研究：运用孔隙介质变形模型和裂纹扩展准则，建立混凝土多阶段的孔隙演化方程；通过不同压力下混凝土基体状态方程和孔隙演化方程的组装，建立混凝土的多阶段孔隙压密状态方程；采用空心球代表性体积元和上限分析方法，建立材料强度的演化方程；基于正侵彻时弹靶半剖面实验技术，通过小口径模型弹高速侵彻实验获取内部破坏图景；基于动力有限元软件计算平台，编制基于孔隙演化的流体弹塑性模型的计算程序；在考虑孔隙演化的流体弹塑性模型基础上，根据塑性/脆性裂纹演化规律，揭示混凝土侵彻、震塌与贯穿破坏机理；上述研究可为工程防护技术和钻地武器设计提供理论支持。

本项目针对强冲击下混凝土宏观本构模型与细观特性关联机制不清，弹体高速侵彻时混凝土靶体破坏机理尚不十分明确等问题开展了系统研究：运用孔隙介质变形模型建立了混凝土的孔隙演化方程；通过不同压力下混凝土基体状态方程和孔隙演化方程的组装，建立了混凝土的多阶段孔隙压密状态方程；采用空心球代表性体积元和上限分析方法，建立了材料强度的演化方程；基于动力有限元软件LS-DYNA，编制了材料模型的计算程序；利用轻气炮和SHPB,开展了侵彻实验和材料性能的冲击实验，并对计算结果进行了验证；从混凝土的应变状态、破坏区力学特性等方面揭示了靶体的破坏机理。上述研究可为工程防护技术和钻地武器设计提供理论支持。