A new discussion on damage softening statistical constitutive model for rocks and method for determining its parameters
A new discussion on damage softening statistical constitutive model for rocks and method for determining its parameters
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作者：
L. Xiang
在现有岩石损伤软化统计本构模型研究的基础上，首先通过讨论模型参数与特征参数（应力-应变全曲线峰值点的应力和应变）之间的关系，建立了特定围压下模型参数与围压的解析表达式。利用莫尔-库仑强度准则，建立了不同围压下岩石峰值应力与围压的关系。再次，通过对不同岩石峰值应变与围压的相关性研究，推导出了具有普遍意义的不同围压下峰值应变的计算公式。提出了一种新的确定模型参数的方法，并由此建立了适用于不同围压的统一的岩石损伤软化统计本构模型。该本构模型参数少，确定方法简单。最后，通过理论计算与实验结果的对比分析，验证了新方法和模型的合理性。
Based on the existing research on damage softening statistical constitutive model for rocks, firstly, the analytical expressions for the model parameters and confining pressure are established for specific confining pressures by discussing the relationship between the model parameters and characteristic parameters (the stress and corresponding strain at the peak point in the complete stress-strain curve). Then, by using the Mohr-Coulomb strength criterion, the relation between the peak stress and confining pressure is developed under different confining pressures. Thirdly, the formula with general significance for the peak strain in different confining pressures is deduced through investigating the correlation between the strain at the peak point and confining pressure for different rocks. Thus, a new method to determine the model parameters is presented, and a unified damage softening statistical constitutive model for rocks which is applicable to different confining pressures is then proposed. This constitutive model has fewer parameters and the method of determining its parameters is also easy. Finally, the rationality of the new method and the proposed model is verified through comparative analysis between the theoretical and experimental results.