沥青混凝土弯曲疲劳试验疲劳损伤分析  

Fatigue damage analysis of aspahlt mixture specimen during cyclic bending test

作　　者：周志刚[1] 张清平[1] 袁秀湘[1] 

机构地区：[1]长沙理工大学道路结构与材料交通行业重点实验室,湖南长沙410004

出　　处：《中南大学学报（自然科学版）》2011年第6期1743-1751,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(50778027);湖南省自然科学基金资助项目(04JJ3033)

摘　　要：针对现有沥青混合料疲劳损伤试验时直接依据刚度或模量计算损伤值而无法真实反映材料微观损伤特性的不足,提出应用反分析方法以得到沥青混凝土的疲劳损伤演化规律。其步骤是:根据沥青混凝土疲劳损伤模型,得到三点弯曲梁试件疲劳损伤力学理论经典解;根据疲劳试验数据确定沥青混凝土材料疲劳损伤模型中的特征参数。应用非线性有限元方法,模拟计算并分析试件疲劳损伤过程中的弯拉应力、挠度、损伤变量、裂纹扩展速率等的变化规律,并预测沥青混凝土试件疲劳寿命及失稳断裂时的裂纹长度。研究结果表明:疲劳寿命的数值模拟结果与试验结果较吻合,证明了所提出的沥青混凝土疲劳损伤模型的合理性和有效性。Based on the fact that damage index is calculated using stiffness or modulus directly in fatigue damage experiment for asphalt mixture and it is unable to reveal the reality of asphalt mixture＇s micro-damage characteristic,the back-analysis method was suggested to determine the fatigue damage characteristic of asphalt mixture.At first,the classic fatigue damage theorical solution of beam specimen during three points bending test was deduced using the fatigue damage model suggested for asphalt mixture,and the characteristic parametres in the model were determined based on the results of fatigue test.The variations of bending stress,deflection,damage index,crack expanding velocity,etc.in the specimen during fatigue damage were simulated by using nonlinear finite element method,and the fatigue life and the crack length while breaking were predicted.The results show that the numercal fatigue life is well identical with experimental results,which proves the reasonableness and effectiveness of the fatigue damage model suggested for asphalt mixture.

关 键 词：沥青混凝土 弯曲疲劳试验 非线性疲劳损伤 仿真 

分 类 号：U416.217[交通运输工程—道路与铁道工程]