双参数抛物型Mohr强度准则及其材料破坏规律研究

RESEARCH ON TWO-PARAMETER PARABOLIC MOHR STRENGTH CRITERION AND ITS DAMAGE REGULARITY

详细推导了双参数抛物型Mohr强度准则的一系列公式。首先,根据简单拉伸和压缩试验推导了该模型参数的公式,讨论了第一主应力和第三主应力之间的关系及破坏模式;然后,定义了摩擦角和破坏角,导出了相应的公式,并且给出了两者之间关系表达式。双参数抛物型Mohr强度准则既可描述剪切破坏模式,又可描述受拉破坏模式,且其对单轴抗压和抗拉强度比没有限制,所推导的破裂角公式可以为今后宏观裂纹开裂方向的计算和破坏模式的确定提供理论基础;而Griffith准则只是双参数抛物型Mohr准则的一种特殊情况。

A series of formulas about two-parameter parabolic Mohr strength criterion are derived. Based on the results of uniaxial tension test and uniaxial compression test, the parameters involved in the criterion can be determined, and the damage pattern is also discussed. After that, the formulas about the rupture angle and the friction angle are presented, and the formula of their relationship is also presented. Two-parameter parabolic Mohr strength criterion can describe both shear failure mode and tensile failure mode. In this criterion, the ratio of the uniaxial compression strength and the uniaxial tension strength can be set any value. The formulas of the rupture angle provide concrete theoretical foundation for the direction of crack face and damage pattern in the computation of macro crack propagation. At last, it is also pointed out that Griffith criterion is only an exceptional case of two-parameter parabolic Mohr strength criterion.