整车多轮动载作用下沥青路面动力响应

车辆荷载作用下沥青路面各结构层受力复杂，现行公路沥青路面设计规范未能考虑车辆振动特性和橡胶轮胎非线性。为研究整车多轮动载作用下沥青路面动力响应，基于车辆动力学、橡胶材料超弹性及沥青路面黏弹性理论，构建整车-橡胶轮胎-沥青路面三维有限元模型，与实际车-路现场测量比较验证本模型的可靠性，对比分析无路面不平度与B级路面不平度激励下，路面各结构层动力响应。结果表明：通过与实际车-路测量结果比较，沥青层底部纵向最大剪应变与实测值误差为5.889%，表明该车-路动力学模型可靠、合理；B级路面不平度激励下，后轴左单轮接地法向力为0~86.526 kN，车体法向振动加速度为-0.451~0.372 m·s^-2，后轴左悬架弹力为60.376~68.42 kN；与无路面不平度相比，后轴左单轮最大接地法向力、车体最大法向加速度、后轴左悬架最大弹力分别增加113%、402.7%、7.4%；与无路面不平度相比，沥青路面上、中、下面层纵向最大压应力分别增加18.91%、12.4%、21.1%，纵向最大拉应力分别增加3.94%、6.25%、33.3%；横向最大压应力分别增加10.43%、8.47%、9.19%，横向最大拉应力分别增加12.19%、13.08%、33.33%，且压应力数值远大于拉应力；竖向最大压应力分别增加19.1%、19.35%、20.07%，竖向最大拉应力分别增加26.93%、7.38%、6.2%，且前轮压应力大于中、后轮压应力。以上数据说明路面不平度对结构层响应影响较大，车辆振动特性及橡胶轮胎与路面非线性接触不容忽略。

Dynamic Response of Asphalt Pavement Under Multi-wheel Dynamic Load

Though the stress of each structural layer of asphalt pavement under vehicle loads is complex, the current design specification of highway asphalt pavement has failed to cover vehicles' vibratory characteristics and rubber tires' nonlinearity. Therefore, to study the dynamic response of asphalt pavement under multi-wheel dynamic loads, based on the theories of vehicle dynamics, hyperelasticity of rubber material, and viscoelasticity of asphalt pavement, a three-dimensional finite element model of the vehicle-rubber tires-asphalt pavement was built. Its reliability was verified by comparisons with actual vehicle-road field measurements to contrast and analyze the dynamic response of pavement's structural layers under no road roughness and class B road roughness. Results show that by being compared with the measurement results of actual vehicle-roads, the error between the maximum longitudinal shear strain at the bottom of the asphalt layer and the measured value is 5.889%, which shows that the vehicle-road dynamic model is reliable and reasonable. Under the excitation of road roughness class B, the grounding normal force of the left single wheel of the rear axle is between 0-86.526 kN, the normal acceleration of the vehicle is between -0.451-0.372 m·s^-2, and the elastic force of the rear axle left suspension is between 60.376-68.42 kN. Compared with no road roughness, the maximum grounding normal force of the left single wheel on the rear axle, maximum normal acceleration of the vehicle, and maximum elastic force of the rear axle left suspension increase by 113%, 402.7%, and 7.4%, respectively. Compared with no road roughness, the longitudinal maximum compressive stresses of the upper, middle, and lower layers increase by 18.91%, 12.4%, and 21.1%, respectively, and the longitudinal maximum tensile stresses increase by 3.94%, 6.25%, and 33.3%, respectively. The transverse maximum compressive stresses increase by 10.43%, 8.47%, and 9.19%, respectively, and the transverse maximum tensile stresses increase by 12.19%, 13.08%, and 33.33%, respectively. The value of compressive stress is much greater than that of tensile stress. The vertical maximum compressive stresses increase respectively by 19.1%, 19.35%, and 20.07%; the vertical maximum tensile stresses increase respectively by 26.93%, 7.38%, and 6.2%; and the compressive stress of the front wheels is greater than that of the middle and rear wheels. The above data show that road roughness has a great influence on the response of the structural layer and that the vibratory characteristic of vehicles and the nonlinear contact between rubber tires and road surfaces should not be ignored.