基于改进Harris函数的岩石蠕变损伤模型及二次开发

针对水电工程中岩石蠕变变形现象,以泥岩为例,开展三轴压缩蠕变试验。基于蠕变试验结果,引入Harris函数,建立一种新的蠕变损伤演化方程。引入一个非线性粘塑性体,与Burgers模型串联并进行损伤演化,从而建立一个新的非线性粘弹塑性蠕变损伤模型。对该模型的三维差分形式进行推导,在FLAC3D平台上利用C++和FISH编程进行二次开发,实现该蠕变损伤本构模型的自定义。利用数学优化软件1stOpt求取模型参数,将该自定义模型及参数应用于三轴压缩蠕变试验的模拟,还原实际试验条件,对比试验数据和模拟值,验证该损伤本构模型的合理性及模型参数的正确性。研究结果可为岩石蠕变损伤本构模型的构建及类似蠕变本构模型的二次开发提供参考。

Creep Damage Model of Rock Based on Improved Harris Function and Its Secondary Development

The creep deformation of rock is remarkable in hydropower engineering. Taking mudstone as the research object, the triaxial compression creep test was carried out. Based on the creep test results, a new creep damage evolution equation was established by introducing Harris function. A new nonlinear viscoelastic-plastic creep damage model was proposed by introducing a nonlinear Burgers body in series with the model. The three-dimensional difference form of the model was deduced, and the C++ and FISH programming were used for the secondary development on the FLAC3D platform to realize the customization of the creep damage constitutive model. By using the mathematical optimization software 1stOpt, the model parameters were obtained. The custom model and parameters were applied to the simulation of triaxial compression creep test. The actual test conditions were reduced, the test data and simulation values were compared, and the rationality of the damage constitutive model and the correctness of the model parameters were proved. The research results can provide some references for construction of creep damage constitutive model and the secondary development of the similar creep constitutive model.