颗粒离散元方法中接触模型的开发

摘要

Generalized Kelvin model for calculation of contact force between particles is deduced based on the research of theoretical background of particle discrete element method. With the object-oriented programming technique and the redeveloped interface of PFC,the generalized Kelvin contact model is developed and used in a verification example. In the example,two particles are bonded together and the relaxation is calculated by PFC and theoretical method. The result shows that the contact force exponentially decreases as time increases,which coincides with the analytical solution. Based on the researches,taking a deep-buried tunnel for example,the cracking and failure of rock are analyzed under conditions of different contact constitutive models. Results show that the generalized Kelvin contact model is better than linear elastic contact model,and the former is more consistent with the calculation chart from Hoek-Brown strength criterion.%在对颗粒离散元方法的理论基础进行深入研究的基础上,推导了广义Kelvin模型颗粒间接触力的理论解和数值解;采用面向对象的程序技术,通过颗粒离散元程序的接口,研制了广义Kelvin接触模型颗粒离散元计算程序;通过算例,验证了程序编制的正确性.在此基础上,以某深埋隧洞为例,计算不同接触本构模型条件下岩体的开裂破坏情况.结果表明,相对于弹性接触关系,采用广义Kelvin接触模型得出的结果与由Hoek-Brown强度准则得出的计算图更为接近.