动能弹侵彻素混凝土板的数值模拟

用二维梁-颗粒模型BPM2D(Beam-Particle Model in Two Dimensions)模拟了刚性弹体侵彻和贯穿素混凝土板的过程．梁-颗粒模型BPM2D是在离散元法基础上,结合有限元法开发的二维数值计算模型．在模型中用三种类型梁单元形成混凝土数值试样．每种类型梁单元的力学性质均按韦布尔(Weibull)分布随机赋值以模拟混凝土细观结构的非均匀性,同时梁单元的强度随应变率不同而变化．利用此模型分析了弹体侵彻下混凝土板的破坏过程,并给出不同弹体初始速度条件下各时刻混凝土和弹体内部速度场．通过将计算结果与实验数据及LS—DYNA程序模拟结果相比较,表明梁-颗粒模型可有效应用于计算和模拟脆性材料动态破坏问题．

NUMERICAL SIMULATION ON THE KINETIC ENERGY PENETRATION AGAINST PLAIN CONCRETE PANEL

The BPM2D (Beam-Particle Model in Two Dimensions) is used to simulate the penetration and perforation of a plain concrete panel. The BPM2D is based on the DEM and the FEM. Three types of beam in the BPM2D are used in the numerical model of concrete, with their mechanical properties varying with their strain-rate and are randomly assigned according to Weibull distribution to reflect the initial heterogeneity of concrete at the mesoscale level. The failure process of a steel bullet perforating into a concrete panel is analyzed by this model. The velocity field in concrete and bullet at different impact velocities are obtained. The comparison of the simulated results with the experimental data and the simulated results of the code LS-DYNA3D shows that the BPM2D can be used to simulate the dynamic failure problems of brittle material.