根据黏弹性理论构建沥青罩面层三维黏弹性有限元模型,运用大型有限元软件ABAQUS进行动态荷载试验,研究了沥青罩面层的力学响应。结果表明,沥青罩面层由于其本身的黏弹性,在动态载荷作用下会产生与弹性材料不同且更为复杂的应力响应,应力状态随加载和卸载而不断变化,加载时其表面为压应力,底层为拉应力,卸载时则相反,其表面为拉应力,底层为压应力;循环载荷下沥青罩面层受压应力和拉应力的交替重复作用,其表面和层底会产生残余应力,随温度的升高,其松弛模量增强,黏弹性减弱,残余应力逐渐减小。相对于把沥青罩面层作为弹性材料的方法,基于黏弹性的分析方法能够更准确地描述沥青罩面层的力学行为特征。

A three-dimensional viscoelastic finite element model of asphalt overlay was constructed based on the viscoelastic characteristics of asphalt mixture, and dynamic loading tests were performed by using the finite element software ABAQUS. The results show that, a different and more complex mechanical response than that of elastic material is generated because of the viscoelastic characteristic of asphalt mixture overlay itself. The stress state changes with the loading and unloading process-a compressive stress is generated on the surface, and a tensile stress is on the bottom surface when loading. The unloading process is on the contrary. A residual stress will be generated on the surface and the bottom surface under the alternately repeated compressive stress and tensile stress. Furthermore, the residual stress decreases with increasing the temperature, while the relaxation capacity increases and the viscoelasticity decreases. This method gives a more accurate and scientific description on the mechanical behavior feature of asphalt overlay than treating the asphalt mixture overlay as an elastic material.