围压对双轴试验力学参数影响的数值模拟研究

Numerical Simulation Study on Influence of Confining Pressure on Mechanical Parameters of Biaxial Test

为了研究围压对双轴试验力学参数的影响,利用离散元方法(二维)数值模拟了不同围压下试件的响应结果,研究了围压对弹性模量、泊松比和强度的影响,给出了0 MPa和25 MPa围压下试件的破坏模式和颗粒间的接触力、位移矢量、裂缝分布。结果表明:围压与弹性模量、强度呈直线增长关系,泊松比随着围压的增大而减小,两者呈二次多项式关系,25 MPa比0 MPa时试件的最大接触力增大28.15%、最大位移增加0.03 mm、裂缝数增加92条。

To study the influence of confining pressure on the mechanical parameters of biaxial test,the response results of specimens are simulated under different confining pressures by discrete element method（two dimention） in this paper.Influence of confining pressure on elastic modulus,Poisson＇s ratio and strength are studied,and failure mode of specimens and contact forces between particles,displacement vector,crack distribution with confining pressures of 0 MPa and 25 MPa are given.The results indicate that the relationships between confining pressure and elastic modulus,strength are linear growth,Poisson＇s ratio decreases as confining pressure increases and their relationship is quadratic polynomial.In addition,the maximum contact force increases 28.15%,the maximum displacement increases 0.03 mm and the number of cracks increases 92 with confining pressure of 25 MPa compared with those of 0 MPa.