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为研究沥青混凝土路面内部反射裂缝在动态荷载作用下的力学响应,采用ABAQUS有限元软件建立分析模型.通过对沥青混凝土蠕变试验曲线进行非线性拟合,得到Prony级数以赋予模型中面层粘弹性材料属性.基于粘弹性理论、时温等效原理、断裂力学及动力学有限元方法,利用半正弦荷载模拟动荷载作用,以断裂参数J积分以及复合应力强度因子作为裂缝扩展评价指标,对路面反射裂缝在不同车速、不同环境温度以及不同材料阻尼系数等条件下的力学响应进行分析.计算结果表明:反射裂缝断裂参数值随车辆行驶速度的增加而减小;不同结构温度下的断裂参数差异不明显;断裂参数曲线随阻尼比的增大而逐渐后移,且最大值逐渐减小.因此,通过改善车辆行驶条件以提高车辆行驶速度,以及通过改进材料组成来增大沥青混凝土阻尼系数,都能够有效延缓反射裂缝扩展速度,延长路面的正常使用寿命.
In order to study the mechanical response of reflective cracks in asphalt concrete pavement under dynamic load, the ABAQUS finite element software was used to establish the analytical model.The Prony series was obtained by non-linear fitting of the creep test curves of asphalt concrete to give the surface layer Viscoelastic material properties. Based on the viscoelastic theory, time-temperature equivalent principle, fracture mechanics and dynamic finite element method, the semi-sinusoidal load is used to simulate the dynamic load, and the fracture parameter J integral and composite stress intensity factor are taken as the evaluation indexes of crack propagation. The mechanical responses of pavement reflection cracks under different vehicle speeds, different ambient temperatures and damping coefficients of different materials are analyzed. The calculated results show that the fracture parameter values of reflective cracks decrease with the increase of vehicle traveling velocity. The fracture under different structure temperatures The parameter difference is not obvious; the fracture parameter curve gradually moves backward with the increase of damping ratio, and the maximum value decreases gradually.Therefore, by improving the driving conditions of vehicles to improve the vehicle running speed and increasing the asphalt concrete damping by improving the material composition Coefficient, can effectively delay the rate of reflection crack propagation, delay The normal life of the road.