应力、应变控制模式下沥青疲劳损伤差异机理分析

发布时间：2018-01-27 16:31

本文关键词： 沥青本构模型疲劳控制模式差异机理　出处：《哈尔滨工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：多年来，沥青及沥青混合料的疲劳损伤特性一直倍受关注和重视。沥青的疲劳试验有应力控制和应变控制两种模式。然而，几乎所有的研究均显示应力、应变两种控制模式下，沥青的疲劳性能具有显著差别，，这种差异性使得沥青疲劳评价指标的确定面临困难，进而导致难以比较不同沥青间抗疲劳性能的优劣、选择优质的沥青用于沥青路面建设。另一方面，尽管近年来部分研究者注意到沥青疲劳损伤差异所带来的问题和混乱，进而越来越重视这方面的研究，但是大部分研究着眼于沥青混合料且现有研究多着眼于现象上的统一，而没有从根本上分析应力、应变控制模式下沥青疲劳损伤的差异机理。因此，挖掘应力、应变两种控制模式下沥青损伤差异机理，从本质上建立应力、应变控制控制模式下统一的沥青疲劳评价指标是十分必要的。针对上述问题，本文首先分别研究了静态荷载和动态荷载作用下沥青的变形特性，在此基础上，参考现有的沥青本构方程，通过比较分析选择了能较准确反映沥青变形特性的本构方程，从而为后面建立沥青的疲劳损伤演化模型提供基础。其次，本文基于不同控制模式下、不同温度下、不同荷载大小下的疲劳试验，通过分析不同控制模式下复数模量、相位角、耗散能、累积耗散能等粘弹参数在疲劳过程中的变化规律，研究了不同控制模式下沥青疲劳特性的差异，从而确定了控制模式的影响阶段和影响阈值。最后，基于不同控制模式下的沥青疲劳变形特性的差异，进一步分析了疲劳过程中不同粘弹参数的变化，从而阐述了沥青的疲劳特性和应力、应变控制模式下沥青疲劳损伤差异机理。在此基础上，结合沥青的本构模型，建立了两种控制模式下累积耗散能的增长模型及其转换关系，进一步提出了两种控制模式下的疲劳损伤演化模型及其转换关系。本研究揭示了沥青疲劳的实质，对于沥青疲劳性能评价和预测具有重要意义。此外对于其他粘弹性材料损伤机理的分析具有一定的参考价值，研究成果对于路面力学和材料学科的发展具有一定的推动作用。
[Abstract]:For many years, the fatigue damage characteristics of asphalt and asphalt mixture have been paid more and more attention. The fatigue test of asphalt has two modes: stress control and strain control. However, almost all researches show stress. Under the strain control mode, the fatigue performance of asphalt is significantly different. This difference makes it difficult to determine the fatigue evaluation index of asphalt, and it is difficult to compare the fatigue performance of different asphalt. On the other hand, although some researchers have noticed the problems and confusion caused by asphalt fatigue damage difference in recent years, more and more attention has been paid to the research in this field. However, most of the researches focus on asphalt mixture and most of the existing researches focus on the unity of phenomenon, but do not fundamentally analyze the differential mechanism of asphalt fatigue damage under strain control mode. Therefore, excavation stress. It is necessary to establish the stress in essence and the unified evaluation index of asphalt fatigue under strain control mode. In order to solve the above problems, the deformation characteristics of asphalt under static and dynamic loads are studied respectively in this paper. On this basis, the existing constitutive equations of asphalt are referred to. Through comparative analysis, the constitutive equation which can accurately reflect the deformation characteristics of asphalt is selected, which provides the basis for establishing the fatigue damage evolution model of asphalt. Secondly, based on the fatigue tests under different control modes, different temperatures and different loads, the complex modulus, phase angle and dissipation energy under different control modes are analyzed. The variation of viscoelastic parameters such as cumulative dissipation energy in fatigue process is studied. The difference of asphalt fatigue characteristics under different control modes is studied and the influence stage and threshold of control mode are determined. Finally, based on the difference of fatigue deformation characteristics of asphalt under different control modes, the variation of different viscoelastic parameters during fatigue process is further analyzed, and the fatigue characteristics and stresses of asphalt are expounded. On the basis of the fatigue damage difference mechanism of asphalt under strain-controlled mode, combined with the constitutive model of asphalt, the growth model of cumulative dissipation energy and its conversion relationship were established under two control modes. Furthermore, the fatigue damage evolution model and its transformation relationship under two control modes are proposed. This study reveals the essence of asphalt fatigue, which is of great significance for the evaluation and prediction of asphalt fatigue performance. In addition, it has a certain reference value for the analysis of damage mechanism of other viscoelastic materials. The research results can promote the development of pavement mechanics and materials.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.217

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