黏结材料双轴试验中裂缝扩展的细观分析  

Mesoscopic Analysis of Crack Extention in Biaxial Test for Bonded Material

作　　者：范圣伟[1] 董旭[1] 

机构地区：[1]山东交通学院土木工程学院,济南市250300

出　　处：《公路》2012年第12期139-143,共5页Highway

基　　金：济南市青年科技明星计划;项目编号20080119

摘　　要：为了分析黏结材料在荷载作用下内部产生裂缝的扩展过程,利用离散元方法生成数字试件,模拟了双轴试验,研究了颗粒间的黏结特性和摩擦特性对杨氏模量、泊松比和裂缝扩展的影响。模拟结果表明:黏结特性的增大,降低了材料的弹性性质,平行黏结强度由1MPa增大至16MPa,杨氏模量由2.92GPa减小至2.58GPa,减小了11.64%,泊松比由0.013增加至0.049,产生的裂缝数减少,法向裂缝数大于切向裂缝。摩擦系数由0.3增大至0.7,杨氏模量增加了3.79%,泊松比减小,产生的裂缝数以摩擦系数0.5为界限,先增加后减小。黏结特性对裂缝扩展和力学指标的影响大于摩擦特性。Digital specimens are generated using the discrete element method to simulate the biaxial test in order to analyze the crack extention process of bonded material under load. The influence of bond characteristics and friction characteristics among particles on the Young＇s modulus, Poisson＇s ratio and crack extension is studied. The simulated results indicate that the elastic properties of bonded material is reduced with the increasing of bond characteristics, and the Young＇s modulus decreases by 11.64% from 2.92 GPa to 2.58 GPa when the parallel bond strength increases from 1 MPa to 16 MPa. In addition, the Poisson＇s ratio increases from 0. 013 to 0. 049, the number of cracks reduces and the number of normal cracks is greater than that of tangential cracks. The Young＇s modulus increases by 3.79%, the Poisson＇s ratio decreases when the friction coefficient increases from 0.3 to 0.7, and the number of cracks increases with the friction coefficients of 0.3, 0.4, 0.5 and then the number of cracks decreases with the friction coefficients of 0.5, 0.6, 0.7. Finally, the influence of bond characteristics on crack extention and mechanical index is greater than those of friction characteristics.

关 键 词：黏结材料 双轴试验 裂缝扩展 杨氏模量 泊松比 

分 类 号：U414.103[交通运输工程—道路与铁道工程]