Influences of Micro Parameters of Discrete Element on Macro Parameters of Clay

Abstract

Based on the discrete element software PFC2D, the biaxial test of clay is simulated. Contact bond model simulates the physical and mechanical behaviors of the clay, and is used to research the influences between the seven microscopic parameters, such as particle radius, particle radius ratio, stiffness ratio, friction coefficient, contact modulus, contact normal bond strength, contact shear bond strength and the macroscopic parameters of the clay, such as Young’s modulus, Poisson’s ratio, cohesion and internal friction angle, respectively. In order to make calibration process of clay efficiently, screen out the two most significant microscopic parameters for each response by design of experiment—the Plackett-Burman design method, and obtain the linear regression equation of macroscopic parameters. After that, estimate the nonlinear relationship between the two microscopic parameters and macroscopic parameters by the Response Surface Methods—Central Composite Design method, and obtain an optimum set of microscopic parameters.