混凝土材料的动态空腔膨胀理论

A dynamic spherical cavity-expansion theory for concrete materials

采用三段式线性状态方程和考虑拉伸破坏的带剪切饱和的Mohr-Coulomb屈服准则描述混凝土材料的本构关系,运用相似变换方法推导出了空腔膨胀动态响应的理论表达式,并运用Runge-Kutta-Felh-berg数值方法给出了球形空腔动态响应的数值解。结果表明:空腔膨胀压力随空腔膨胀速度和剪切饱和强度的增加而增加,在空腔膨胀速度较高时,考虑剪切饱和时的空腔膨胀压力明显小于不考虑剪切饱和时的空腔膨胀压力。

The constitutive descriptions of concrete materials idealize the pressure-volumetric strain relationship as the tri-linear equation of state and idealize the shear strength-pressure relationship as the Mohr-Coulomb yield criterion considering the tension cutoff and the shear saturation. The dynamic response expression of the spherical cavity expansion is derived by the self-similar methods, and the dynamic response numerical solution is given by the Runge-Kutta-Felberg method. The result shows that the cavity expansion pressures increase with the cavity expansion velocity and the shear saturation strength, and the cavity expansion pressures considering the shear saturation are less than those without considering the shear saturation in case of the high cavity expansion velocity.