基于摩尔库伦准则岩石材料UMAT子程序二次开发

发布时间：2018-05-29 13:47

本文选题：岩石材料 + 摩尔库伦准则　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：近年来，国内外众多重大岩体工程相继发生失稳破坏，造成了巨大的经济损失和大量的人员伤亡。然而，现有的数值方法却不能够很好地模拟岩体工程的稳定性。因此，开发一种能够考虑岩石裂纹的萌生、扩展和贯通并且可以模拟岩体工程稳定性的程序，是一个迫切需要解决的问题。ABAQUS是现在通用的有限元专业软件之一，具有强大的非线性分析功能，同时ABAQUS提供的二次开发子程序接口可以方便用户根据自身需要建立用户子程序，扩充ABAQUS的用途。其中UMAT子程序接口具有稳定性好、开放性强等特点，被众多学者用来研究和开发本构模型。因此，本文在研究岩石损伤统计本构模型的基础上，给出了基于摩尔库伦准则的岩石弹塑性UMAT子程序，，并对其参数进行了分析。在对岩石的损伤统计本构模型进行研究时，采用了新的岩石微元强度量方法及考虑了岩石损伤阀值的影响。同时推导了岩石本构中损伤变量的表达式，并分析了岩石本构模型参数的确定，最终给出了岩石本构程序设计流程。岩石在产生损伤前就己经进入弹塑性阶段，然而最常采用的判断岩石材料是否屈服的摩尔库伦准则存在数值计算繁琐和收敛缓慢等缺点，因此本文对传统摩尔库伦准则采用屈服函数拐角处理和双曲线逼近屈服函数两种方法进行改进。求解出了改进的屈服函数一阶偏导数及势函数的一阶偏导数、二阶偏导数的表达式，此表达式可用于弹塑性本构模型的塑性修正及一致性切线模量的计算。本文基于改进的摩尔库伦准则，编写了岩石损伤统计本构模型中未发生损伤部分的弹塑性本构模型UMAT子程序。分别采用单轴压缩试验、纯剪切试验、单轴拉伸试验对比基于改进后的摩尔库伦准则UMAT子程序的计算结果与ABAQUS自带摩尔库伦准则程序的计算结果，验证了本文基于摩尔库伦准则所开发的未考虑损伤的岩石弹塑性本构模型UMAT子程序的准确性。运用所开发的子程序分析了单轴压缩试验、纯剪切试验、单轴拉伸试验三种不同情况下过渡角的变化对应力应变计算结果的影响。最后，给出岩石损伤统计本构模型中产生损伤阶段的算法设计思路。
[Abstract]:In recent years, a large number of major rock mass engineering at home and abroad have occurred instability damage, resulting in huge economic losses and a large number of casualties. However, the existing numerical methods can not well simulate the stability of rock mass engineering. Therefore, it is an urgent problem to develop a program that can consider the initiation, expansion and penetration of rock cracks and simulate the stability of rock mass engineering. Abaqus is one of the general finite element software. It has powerful nonlinear analysis function and the secondary development subroutine interface provided by ABAQUS can facilitate users to establish user subroutines according to their own needs and expand the use of ABAQUS. The UMAT subroutine interface is characterized by good stability and openness, which is used by many scholars to study and develop constitutive models. Therefore, on the basis of studying the statistical constitutive model of rock damage, a rock elastoplastic UMAT subroutine based on the Moore Coulomb criterion is presented and its parameters are analyzed. In the study of the statistical constitutive model of rock damage, a new method of rock microelement strength is adopted and the influence of rock damage threshold is considered. At the same time, the expression of damage variable in rock constitutive model is derived, and the determination of rock constitutive model parameters is analyzed. Finally, the flow chart of rock constitutive program design is given. Rock has already entered the elastic-plastic stage before the damage. However, the most commonly used Moore Coulomb criterion to judge the yield of rock materials has the disadvantages of cumbersome numerical calculation and slow convergence. Therefore, the traditional Moore Coulomb criterion is improved by two methods: the corner treatment of yield function and the approximation of yield function by hyperbolic approximation. The expressions of the first order partial derivative and the second order partial derivative of the improved yield function and the potential function are obtained. This expression can be used for the plastic modification of the elastoplastic constitutive model and the calculation of the consistent tangent modulus. Based on the improved Moore Coulomb criterion, the UMAT subroutine of the elastoplastic constitutive model without damage in the statistical constitutive model of rock damage is compiled. The results of uniaxial compression test, pure shear test and uniaxial tensile test were compared between the results of UMAT subroutine based on the improved Mohr Coulomb criterion and the results of ABAQUS's own Moll Coulomb Coulomb Criterion program. The accuracy of the UMAT subprogram of the elastoplastic constitutive model without damage developed in this paper based on the Moore Coulomb criterion is verified. The influence of the transition angle on the stress and strain calculation results under three different conditions: uniaxial compression test, pure shear test and uniaxial tensile test is analyzed by using the developed subroutine. Finally, the algorithm design of the damage phase in the statistical constitutive model of rock damage is given.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU45

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