强冲击载荷下混凝土动态本构关系

利用一级轻气炮对混凝土靶板进行冲击压缩试验,测量出不同冲击速度下的压力-时间信号曲线。采用拉氏分析方法对实验数据进行分析,得到了流场中各力学量沿时-空的分布规律,从而得到混凝土材料应力-应变试验曲线。在试验研究及拉氏分析的基础上,分析混凝土材料在强冲击载荷下的动态本构特性。最后,结合损伤率型演化和粘弹性理论,建立了混凝土材料的损伤型粘弹性本构方程。数值拟合表明理论预示与试验吻合良好。

DYNAMIC CONSTITUTIVE RELATIONSHIP OF CONCRETE SUBJECTED TO SHOCK LOADING

To study the dynamic properties of concrete subjected to shock loading, stress-time curves of concrete in different velocity were measured using the planar impact technique. The Lagrange analysis method is used to process the data, and the distributions of the mechanical parameters against time and space in the flow field are obtained. The mechanical properties and deformation characteristic of concrete at high strain rate are analyzed and the stress-strain curves of concrete are obtained. It is shown that the properties of concrete are nonlinear and sensitive to strain-rates. A visco-elasticity constitutive relationship of concrete is established according to damage evolution. Numerical results are verified by experimental data.