冲击载荷下混凝土本构模型构建研究

 在对混凝土动态力学性能和现有本构模型综合分析的基础上，构建了一个新的适用于冲击响应问题数值分析的混凝土本构模型。该本构模型全面考虑了压力、应力第三不变量、变形的硬化和软化、应变率强化以及拉伸损伤等各个影响因素。将其加入LTZ-2D程序，确定了本构模型参数，对混凝土靶板的穿透问题进行了数值验证分析。计算得到的弹体剩余速度同实验结果基本一致，同时得到了混凝土靶板破裂的计算图像。计算结果及其分析表明，所构建的本构模型能够较好地反映冲击载荷作用下混凝土动态响应的主要特性。

Building of a Constitutive Model for Concrete under Dynamic Impact

By analyzing both of dynamic behavior and existing constitutive models of concrete,a new constitutive model has been built to simulate dynamic response of concrete.The main factors such as pressure,the third invariant of stress tensor,strain hardening and softening,stain rate and tensile damage have been taken into account in the constitutive model.After calibrating all parameters of the model,simulation of a perforation problem on(concrete) target has been carried out with the Lagrangian finite element code LTZ-2D.The computed results of(residual) velocity are well consistent with the test data,and a reasonable figure of fractured concrete target is(obtained).Results demonstrated that the built constitutive model could well describe the main characters of(concrete) under impact loading.