软弱夹层几何参数对试样力学行为影响颗粒元模拟研究

基于离散元理论的颗粒元程序,采用颗粒接触连接模型和滑动模型,建立了含软弱夹层试样的颗粒元模型。通过数值模型实验,对不同软弱夹层几何参数试样进行加载模拟,探讨了不同夹层厚度及不同倾角条件下试样的破坏过程和破坏形式,并分析其对试样强度的影响。模拟结果表明,裂隙首先产生于软弱夹层处,随着荷载的增加,再逐渐扩展,呈现渐进性破坏特征;夹层越厚,倾角越大,试样沿软弱夹层呈现较强的滑动特征,如果夹层薄且缓,软弱夹层成为试样破坏的非控制因素;软弱夹层厚度和夹角对试样的峰值强度都有影响,随软弱夹层厚度和夹角的增大,试样的峰值强度降低。

PARTICLE FLOW CODE SIMULATION OF SPECIMEN MECHANICAL BEHAVIOR WITH DIFFERENT GEOMETRIC PARAMETERS OF WEAK SEAMS

Based on the distinct element method of particle flow,a specimen with weak seam of Particle Flow Code(PFC) model is made by using the contact-bond model and the slip model.The numerical model test is carried on with different weak seam parameters.Then the paper discusses contrasting failure process and form under different weak seam thickness as well as different inclination angle conditions,and analyzes the influence to specimen strength.Simulation result indicates that fissures are produced first in weak seam and then are expanded with loading,which presents the typical progressive failure process.When the weak seam is thicker and its obliquity is steeper,the specimen presenting the feature to slide along with the weak seam becomes more obvious.But if it is thin and small,the weak seam doesn't dominate the destroying of the specimen.The thickness and obliquity of the weak seam have influence on the specimen peak strength.The peak strength is decreased when the thickness and obliquity are increased.The relation between the kind of failure characteristic and the geometric parameters is obtained from the numerical simulation.This relation offers a further understanding about mechanical property of weak seam and progressive failure.