基于扩展有限元的沥青路面半刚性基层反射裂缝扩展模拟分析

发布时间：2019-02-24 16:31

【摘要】：目前我国沥青路面半刚性基层材料主要是水硬性结合料处治的稳定碎砾石基层材料,由于外界因素的影响以及筑路材料本身的特性,半刚性基层极易产生初始裂缝。基层一旦开裂,在交通荷载、温湿度变化以及其他因素作用下,裂缝尖端产生应力集中,导致裂缝向面层方向扩展,进而加速路面结构的破坏进程,严重影响沥青路面结构的长期使用性能及使用寿命。因此,对半刚性基层反射裂缝的扩展研究具有重要的理论意义和工程价值。对于半刚性基层反射裂缝扩展的问题,既有研究大多只考虑了交通荷载的影响,也有少部分研究了温度的影响,但对于交通荷载和温度共同作用下的研究极少;另一方面,既有研究大多采用传统有限元的数值模拟方法,此方法在计算精度等方面存在严重的缺陷;并且,既有研究均以摩擦系数表征层间接触状态,此方法仅能模拟静态的接触状态;此外,既有研究中对于沥青混合料本构,大多采用线弹性,少部分采用静粘弹性,极少部分采用动态模量但没有同时考虑加载频率和温度的影响。鉴于以上分析,本文着眼于扩展有限元法在模拟裂缝扩展类问题的优势,利用ABAQUS软件及其XFEM模块,沥青混合料采用考虑受加载频率和温度影响的动态模量,并基于渐进损伤的脱层失效理论模拟基面层之间动态的层间接触状态,分析了沥青路面半刚性基层反射裂缝的扩展,主要内容如下:(1)利用ABAQUS软件及其XFEM模块,采用沥青混合料受加载频率和温度影响的动态模量本构,考虑反射裂缝扩展至面层和未扩展至面层两种状态,建立了沥青路面半刚性基层反射裂缝扩展的三维扩展有限元模型。(2)分析交通荷载单独作用下半刚性基层反射裂缝的扩展,研究了动载作用下各种影响因素对基层反射裂缝扩展的影响,并基于渐进损伤的脱层理论研究了基面层间的结合状态对反射裂缝扩展的影响。(3)分析温度非周期性变化和周期性变化作用下半刚性基层反射裂缝的扩展,研究了温度作用下各种影响因素对基层反射裂缝扩展的影响,并基于渐进损伤的脱层理论研究了基面层间的结合状态对反射裂缝扩展的影响。(4)分析交通荷载和温度周期变化与非周期性变化共同作用下半刚性基层反射裂缝的扩展,在交通荷载单独作用、温度单独作用、交通荷载与温度共同作用下,对比分析半刚性基层反射裂缝的扩展情况以及基于Paris公式的疲劳扩展寿命。
[Abstract]:At present, the semi-rigid base material of asphalt pavement in China is mainly treated by hydraulic binder. Due to the influence of external factors and the characteristics of road construction materials, the semi-rigid base is prone to produce initial cracks. Once the base is cracked, under the action of traffic load, temperature and humidity change and other factors, the crack tip produces stress concentration, which leads to the crack spreading to the surface, and then accelerates the damage process of the pavement structure. The long-term service performance and service life of asphalt pavement structure are seriously affected. Therefore, it has important theoretical significance and engineering value to study the propagation of reflection cracks in semi-rigid base. For the problem of reflection crack propagation of semi-rigid base, most of the studies only consider the influence of traffic load, but also a small part of the study of temperature, but the study of traffic load and temperature together is very rare. On the other hand, the traditional finite element numerical simulation method is mostly used in the existing research, which has serious defects in the calculation accuracy and so on. Moreover, the friction coefficient is used to characterize the contact state between the layers, and this method can only simulate the static contact state. In addition, linear elasticity, static viscoelasticity and dynamic modulus are used in most of the existing studies, but the effects of loading frequency and temperature are not considered. In view of the above analysis, this paper focuses on the advantages of the extended finite element method in simulating crack propagation problems. Using ABAQUS software and its XFEM module, the dynamic modulus of asphalt mixture considering the influence of loading frequency and temperature is adopted. Based on the delamination failure theory of progressive damage, the dynamic interlayer contact state between the base layers is simulated, and the propagation of reflection cracks in semi-rigid base course of asphalt pavement is analyzed. The main contents are as follows: (1) using ABAQUS software and its XFEM module, The dynamic modulus constitutive model of asphalt mixture affected by loading frequency and temperature is adopted, and the reflection crack is considered to extend to the surface layer and not to the surface layer. The finite element model for the reflection crack propagation of semi-rigid base course of asphalt pavement is established. (2) the propagation of reflection crack of semi-rigid base course under the action of traffic load alone is analyzed. The influence of various factors on the propagation of reflection crack in the base course under dynamic load is studied. Based on the delamination theory of progressive damage, the influence of the bonding state between the base layers on the propagation of reflective cracks is studied. (3) the propagation of reflection cracks in semi-rigid base is analyzed under the action of non-periodic and periodic temperature variations. The influence of various factors on the propagation of reflection cracks in the base course under the action of temperature is studied. Based on the delamination theory of progressive damage, the influence of the bonding state between the base layers on the propagation of reflective cracks is studied. (4) the propagation of reflective cracks in semi-rigid base is analyzed under the combined action of traffic load and temperature periodic variation and non-periodic variation. Under the combined action of traffic load, temperature, traffic load and temperature, the propagation of reflection crack in semi-rigid base and fatigue life based on Paris formula are compared and analyzed.
【学位授予单位】：北京交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U416.217

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