以路面疲劳断裂力学基本理论为基础,采用二维断裂分析软件FRANC2D对设置应力吸收层的复合式路面在车辆荷载和温度荷载共同作用下反射裂缝的扩展路径进行模拟,并对复合式路面的疲劳寿命进行预测与分析,进而研究应力吸收层的抗裂机理。研究结果表明:反射裂缝在应力吸收层内扩展速度明显小于在沥青加铺层;设置应力吸收层后,路面疲劳寿命是相同厚度沥青加铺层结构疲劳寿命的3.36倍,主要是因为应力吸收层的模量较低,其变形能力较强,所以设置应力吸收层可以对裂尖应力进行有效扩散,从而延缓反射裂缝的扩展速度和延长路面使用寿命。
According to the theory of pavement fatigue fracture mechanics and the two-dimensional finite element software, reflection crack propagation path of composite pavement was simulated and the fatigue life was forecas-ted and analyzed. The crack mechanism of stress absorbing layer was studied. The result shows that: The exten-sion speed of the reflection crack in stress absorbing layer is significantly less than that in the asphalt layer. The fatigue life increased to 3.36 times after setting the stress absorbing layer. This is because the modulus of stress absorbing layer is lower and its deformation ability is stronger. So it can delay the reflective crack extension rate and prolong the service life of pavement when setting the stress absorbing layer.