考虑接触特性的路面结构动态响应分析

发布时间：2018-06-06 15:54

本文选题：分形 + 裂缝修补　；参考：《合肥工业大学》2017年硕士论文

【摘要】：路面开裂和路面拼接是道路工程中十分常见的含缝工作结构,本文的主要目的是在充分考虑含缝结构材料之间的几何接触特性和界面粘结特性的情况下,分析其在车辆荷载下的动态力学响应。路面开裂是水泥混凝土路面的一种常见病害,研究断裂面的表面形状和重构有利于量化评价修补效果。通过自制断面测量仪测得真实断裂面的分形维数D和轮廓算数平均差G后,基于两向异性的W-M法进行裂缝区域的空间几何重构。通过含缝柱状试件的冲击试验,验证了裂缝区域重构方法的有效性。耦合重构裂缝区域和车辆轮胎动载的水泥混凝土路面足尺仿真表明,采用非规则断裂面时裂缝区域的受力状态比采用规则断裂面时的结果更不利。以水泥材料为例研究裂缝修补料的强度形成过程,本文提出一种参数识别迭代算法,可合理确定水化动力学参数,其生成的水化速率曲线与试验数据具有较好的吻合度。水泥水化数值仿真试验可以预测绝热情况下水泥混凝土的温度变化,能替代绝热温升试验获取水化热数据。依据BSE图像中水化产物面积比获得的水化程度指数函数可以较好地吻合试验数据,能替代传统水化热法进行水化动力学分析。结果表明本文的研究可提高水化动力学参数的识别精度,并为水化动力学分析提供新的研究手段。最后以水泥稳定碎石为例,研究了其动态弹性模量随水化程度及龄期的变化关系,为路面拼接中合理选择基层养护龄期作准备。对于路面拼接,依据双圆荷载下二维拼接模型计算得到的应变能密度指标,分别得到了面层和基层的最佳拼接尺寸,并以此建立三维路面拼接模型。耦合车辆的轮胎模型后,分析车辆荷载下不同拼接缝上方沥青混凝土层底和水泥稳定碎石层底的应变能密度,并分别研究了不同界面参数、水泥稳定碎石参数和不同加铺厚度的CA砂浆层对计算结果的影响。建立沥青混凝土和水泥稳定碎石的小梁弯曲试验数值模型,分别得到了单次荷载作用下的总应变密度和疲劳极限次数关系的数学模型。基于三维拼接模型的应变能密度计算结果,预估得到了车辆荷载下沥青混凝土层和水泥稳定碎石层的疲劳极限次数。
[Abstract]:Pavement cracking and pavement splicing are very common jointed working structures in road engineering. The main purpose of this paper is to fully consider the geometric contact characteristics and interface bonding characteristics of jointed structure materials. The dynamic mechanical response under vehicle load is analyzed. Pavement cracking is a common disease of cement concrete pavement. After the fractal dimension D and the average difference of the contour number G of the real fracture surface were measured by the self-made cross-section measuring instrument, the spatial geometric reconstruction of the fracture area was carried out based on the W-M method of two diameters. The effectiveness of the method is verified by impact tests of cylindrical specimens with cracks. The full-scale simulation of cement concrete pavement with coupled reconstruction of crack area and vehicle tire dynamic load shows that the stress state of crack area with irregular fracture surface is more disadvantageous than that with regular fracture surface. Taking cement material as an example to study the strength forming process of crack repairing material, an iterative algorithm for parameter identification is proposed in this paper, which can reasonably determine the hydration kinetic parameters. The hydration rate curve generated by the method is in good agreement with the experimental data. The numerical simulation test of cement hydration can predict the temperature change of cement concrete under adiabatic condition and can replace the adiabatic temperature rise test to obtain the hydration heat data. According to the area ratio of hydration product in BSE image, the hydration degree index function can fit the test data well, and can replace the traditional hydration heat method to analyze the hydration kinetics. The results show that the research in this paper can improve the identification accuracy of hydration kinetic parameters and provide a new research method for hydration kinetics analysis. Finally, taking cement stabilized macadam as an example, the relationship between dynamic modulus of elasticity and hydration degree and age is studied, so as to prepare for the reasonable selection of curing age of base course in pavement splicing. For pavement splicing, according to the strain energy density index calculated by two-dimensional splicing model under double circular load, the optimum stitching dimensions of surface layer and base course are obtained, respectively, and the 3D pavement splicing model is established. After coupling the tire model of the vehicle, the strain energy density of asphalt concrete bottom and cement stabilized gravel layer bottom above different jointed joints under vehicle load is analyzed, and the different interface parameters are studied respectively. The effect of cement stabilized macadam parameters and CA mortar with different overlay thickness on the calculation results. The numerical model of trabecular bending test of asphalt concrete and cement stabilized macadam is established, and the mathematical models of the relationship between the total strain density and the fatigue limit times under single load are obtained respectively. Based on the calculation results of strain energy density of 3D splicing model, the fatigue limit times of asphalt concrete layer and cement stabilized macadam layer under vehicle load are estimated.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U418.6

【相似文献】