沥青路面多尺度力学分析方法及模型研究

发布时间：2018-05-18 05:55

本文选题：沥青路面 + 多尺度模型　；参考：《哈尔滨工业大学》2014年博士论文

【摘要】：沥青路面结构的破损行为是道路工程领域最为重要和热点的问题，为能够合理、准确地分析沥青混凝土路面结构的破坏行为，需要借助力学理论方法对路面结构进行动力学行为分析，并利用完善的多尺度破坏理论来判断沥青材料破坏行为的始末。本论文围绕上述问题开展了路面结构动力学系统力学参数理论分析和确定、沥青混凝土路面结构动力响应的研究和沥青混凝土材料多尺度破坏行为的研究。研究的主要内容如下：利用复合材料细观力学理论推导了沥青混凝土动态模量的解析方法，比较了自洽方法与广义自洽方法在求解沥青混凝土材料动态模量时的优缺点，发现广义自洽方法更适于计算沥青混凝土动态模量。提出并推导得到了一种考虑沥青混合料级配特性的动态模量求解方法，并与试验对比验证了此模型的精度，发现其在趋势上与试验结果很接近，但是在数值结果上存在较大误差。进而提出一种修正的能够考虑级配特性的Hashion模型来计算沥青混凝土的动态模量，发现这一方法具有较好的预测精度。基于上述方法将沥青混凝土中的空隙采用裂纹广义自洽方法进行模拟，计算结果整体上略大于试验值。但是上述两种方法为解析求解沥青混凝土动态模量提供了近似的上下限。基于MATLAB软件平台，结合ABAQUS、ANSYS、PYTHON和FORTRAN建立了沥青混凝土几何建模-有限元网格划分-动态模量求解-后处理分析统计等一体化程序。利用这一程序研究不同骨料空间组成的沥青混凝土材料动态模量数值，发现计算的结果涵盖的区间与试验结果接近，从而证明了沥青混凝土动态模量为一个统计参量，其具有均值和方差特征。建立了不同尺寸下沥青混凝土动态模量求解的有限元模型，并通过近50000次的计算得到了沥青混凝土动态模量均值与方差变化特征与沥青混凝土动态模量试件尺寸之间的关系，并基于上述分析建立了沥青混凝土动态模量统计学模型。利用有限元方法建立不同种类（全钢性和半钢性）与不同花纹类型的轮胎三维有限元模型，并分析了轮胎接地压力的分布情况，为了解与轮胎直接作用部分的路面结构力学行为提供了借鉴。此外在分析中发现全钢性子午线轮胎模型的接地压力在载荷等级达到一定程度后会随着载荷等级的增加而只增加纵向接触长度。给出了一种路面平整度随机生成和建模的程序，利用其实现路面在含平整度激励的刚性路面上轮胎滚动过程模拟，计算得到了轮胎中心位置的竖向位移时程变化曲线。基于显式与隐式交互插值技术完成了轮胎-路面耦合动力学模型，并用此模型分析和计算了路面结构的动力学响应。此外为节省计算成本，本文还开发了一种路面结构过渡网格基元来完成路面的三维有限元建模。基于Hertz接触理论建立了车辆-轮胎-路面耦合分析动力学模型并用试验进行验证，取得了非常理想的结果。利用子模型计算完成了路面多尺度动力响应分析，并对沥青混凝土材料为沥青胶浆和石料两相材料时的情况进行了多极化分析。基于面积加权非局部化理论和塑性损伤耦合理论建立了能够描述非局部化变形带的本构模型。该模型避免网格敏感。基于高阶梯度理论模拟了沥青混凝土材料可能存在的尺寸效应，并初步解释了沥青内部夹杂石料情况下可能出现的尺寸硬化现象。基于扩展有限元方法分析了沥青混凝土材料的宏观断裂行为，，其中断裂模式包括极限断裂模式和疲劳断裂模式。本文为系统地使用力学分析和研究沥青混凝土路面结构在动力学体系下的破坏行为提供了一定的理论指导，并为沥青混凝土的多尺度破坏行为的研究提供一定的基础.
[Abstract]:The damage behavior of asphalt pavement structure is one of the most important and hot issues in the field of road engineering . In order to rationally and accurately analyze the damage behavior of asphalt concrete pavement structure , it is necessary to analyze the dynamic behavior of asphalt concrete pavement structure with the aid of the theory of mechanics .

The analytical method of dynamic modulus of asphalt concrete is derived by using the theory of mesoscopic mechanics of composite material . The advantages and disadvantages of self - consistent method and generalized self - consistent method in solving the dynamic modulus of asphalt concrete are compared . It is found that the generalized self - consistent method is more suitable for calculating the dynamic modulus of asphalt concrete .

Based on the software platform of MATLAB , the integration procedure of asphalt concrete geometric modeling - finite element mesh division - dynamic modulus solution - post - treatment analysis and statistics is established by combining the finite element mesh division - dynamic modulus solution and post - treatment analysis statistics . The dynamic modulus of asphalt concrete is found to be close to the test result . The relationship between the dynamic modulus mean value of asphalt concrete and the dimension of the dynamic modulus test piece of asphalt concrete is obtained through the calculation of nearly 50000 times , and the dynamic modulus statistical model of asphalt concrete is established based on the analysis .

Based on the finite element method , three - dimensional finite element model of tire with different pattern types ( all - steel and semi - steel ) and different pattern types is established , and the distribution of the tire grounding pressure is analyzed . In addition , it is found that the ground pressure of all - steel radial tire model can only increase the longitudinal contact length with the increase of the load level after the load level reaches a certain degree .

This paper presents a process for the random generation and modeling of pavement evenness . It is used to simulate the tire rolling process on the rigid pavement with flatness excitation . The dynamic response of the road surface is obtained by using the explicit and implicit interactive interpolation technique .

Based on the theory of area weighted nonlocality and the theory of plastic damage coupling , this paper establishes a constitutive model which can describe the non - localized deformation zone . The model avoids grid sensitivity . Based on the high - order gradient theory , the possible size effect of asphalt concrete is simulated . The macro - fracture behavior of asphalt concrete material is analyzed based on the extended finite element method . The fracture mode includes ultimate fracture mode and fatigue fracture mode .

This paper provides some theoretical guidance for the systematic use of mechanical analysis and the study of the damage behavior of asphalt concrete pavement structure under dynamic system , and provides some basis for the study of multi - scale damage behavior of asphalt concrete .
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2014
【分类号】：U416.217

【参考文献】