机场复合道面反射裂缝的力学分析

Mechanical Analysis of Reflective Crack for Airport Composite Pavement

基于弹性断裂力学理论和平面应变假设,应用ABAQUS有限元软件建立了不同深度反射裂缝在不同位置荷载作用下的复合道面有限元模型,分析了不同沥青面层裂缝深度以及不同荷载作用位置对复合道面应力和裂缝尖端应力强度因子的影响,并对A型荷载、B型荷载和C型荷载3种荷载位置在不同裂缝深度的计算结果进行了对比分析。研究结果表明:最大应力随裂缝深度的增加而增加,说明裂缝深度对沥青面层的最大应力有较大的影响;荷载作用位置不同时,沥青面层裂缝中最大应力值相差较大,说明荷载作用位置对沥青面层的最大应力有较大的影响;随着裂缝深度的增大,应力强度因子KI不断增大,说明裂缝的扩展主要受KI的控制;荷载位置不同时,应力强度因子KI值变化较大,说明荷载位置对KI影响显著,且A型荷载影响最大,B型荷载影响次之,C型荷载影响最小。

Based on the theory of elastic fracture mechanics and the assumption of plane strain, a finite element model of the composite pavement under different depth reflection cracks and different load positions is established by using ABAQUS finite element software. The influences on the stress and the stress intensity factor at the crack tip of the composite pavement under different crack depths and different load positions are analyzed. The computational results of three kinds of load position for A type load, B type load and C type load are compared. Research results show that the maximum stress increases with the increase of crack depth, which indicates that the crack depth has a great influence on the maximum stress of asphalt surface layer. With the different load positions, the maximum stress of asphalt surface layer is quite different, which indicates that the position of the load has a great influence on the maximum stress of the asphalt surface layer. With the increase of the crack depth, the stress intensity factor KI increases, which indicates that the crack propagation is mainly controlled by the stress intensity factor KI. The stress intensity factor KI varies significantly with different load positions, which shows that the stress intensity factor KI has significant influence on the load position. The influence of A type load is greater than B type load and C type load, and B type load is greater than C type load.