沥青路面裂缝的疲劳损伤力学数值分析

发布时间：2018-04-22 04:19

本文选题：沥青路面 + 裂缝　；参考：《东北大学》2014年硕士论文

【摘要】：车辆荷载反复作用引起路面的疲劳裂缝是沥青路面主要损坏形式之一。究其本质,实际是路沥青面层材料发生了疲劳损伤和破坏。只有弄清楚车辆荷载作用下沥青面层疲劳裂缝形成及开展过程才能更有效的指导沥青路面的抗疲劳设计。沥青混合料常温下即可表现出一定的粘塑性,也就是说沥青路面在绝大多数工作环境中均会表现出一定粘塑性。国内外学者将沥青混合料视为粘弹性材料来进行疲劳研究,无疑有失偏颇。由于传统的疲劳力学仅能考虑疲劳裂缝的形成阶段,不能用于研究疲劳裂缝从形成到扩展的整个过程。而疲劳损伤力学作为破坏力学新兴的学科分支,恰恰弥补了传统疲劳力学的缺陷。而为了实现运用疲劳损伤力学理论对沥青路面裂缝形成及开展过程的分析,可借助有限元软件来进行数值模拟。鉴于以上几个方面,本文进行了如下工作：1)本文以修正Burgers粘弹塑性模型为基础,推导了半正弦荷载作用下沥青混合料的粘弹塑性损伤本构方程,得到了累积应变的表达式。2)分析总结了文献中各种疲劳损伤损伤模型,并以大量文献中疲劳试验数据为基础,提出了能够考虑加载频率、温度和应力比的损伤演化模型。3)进行了沥青混合料的劈裂疲劳试验,并利用Origin软件对疲劳试验数据进行了疲劳寿命方程和损伤本构方程的参数拟合。4)以拟合的损伤演化方程和损伤本构方程为基础,利用ansys软件对沥青路面结构整体建模,成功模拟了车轮荷载反复作用下沥青面层裂缝形成及开展过程,分析了各单元的损伤分布和发展规律以及应力应变规律。分析了不同基层厚度和不同基层模量对面层疲劳裂缝的影响。分析了面层与基层接触状态对于面层疲劳裂缝的影响。
[Abstract]:Fatigue crack caused by repeated vehicle loads is one of the main damage forms of asphalt pavement. In fact, fatigue damage and failure occurred in asphalt pavement. Only by making clear the forming and developing process of fatigue crack of asphalt pavement under vehicle load can the anti-fatigue design of asphalt pavement be more effective. Asphalt mixture can show a certain viscoplasticity at room temperature, that is, asphalt pavement will show a certain viscoplasticity in most working environment. Scholars at home and abroad regard asphalt mixture as viscoelastic material for fatigue research, which is undoubtedly biased. Because the traditional fatigue mechanics can only consider the forming stage of fatigue crack, it can not be used to study the whole process of fatigue crack from formation to propagation. As a new branch of destructive force, fatigue damage mechanics makes up for the defects of traditional fatigue mechanics. In order to analyze the crack formation and development process of asphalt pavement using fatigue damage mechanics theory, the finite element software can be used to carry out numerical simulation. Based on the modified Burgers viscoelastic-plastic model, the constitutive equation of viscoelastic-plastic damage of asphalt mixture under semi-sinusoidal loading is derived. The expression of cumulative strain (.2) is obtained. Various fatigue damage damage models in the literature are summarized. Based on a large number of fatigue test data in literature, it is proposed that the loading frequency can be taken into account. The damage evolution model of temperature and stress ratio. 3) the splitting fatigue test of asphalt mixture was carried out. The parameters of fatigue life equation and damage constitutive equation are fitted with Origin software. 4) based on the fitted damage evolution equation and damage constitutive equation, the whole structure of asphalt pavement is modeled by ansys software. The formation and development of asphalt surface cracks under repeated wheel loads are successfully simulated, and the damage distribution, development law and stress-strain law of each unit are analyzed. The influence of different thickness and modulus on fatigue crack in opposite layer is analyzed. The influence of the contact state between the surface layer and the base course on the fatigue crack of the surface layer is analyzed.
【学位授予单位】：东北大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.217

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