轮胎磨耗及其温度场的理论与实验研究

发布时间：2018-05-24 22:33

  本文选题：橡胶磨耗 + 摩擦系数　； 参考：《青岛科技大学》2017年博士论文

【摘要】：磨耗是由于机械作用或化学反应在接触物体表面产生的一种材料逐渐损耗的现象,磨耗发生在有摩擦力存在条件下任意二个物体之间相互作用相对滑移的过程中,二个接触面都有材料损失和几何形状的改变,是具有时变特征的渐进的动态过程。轮胎与地面的摩擦作用和力的传递提供了汽车运动所需的各项力和力矩,汽车行驶过程中必然会造成轮胎的磨耗。轮胎是由橡胶及纤维或钢丝增强材料组成的壳结构体,具有黏弹性、大变形、非线性及温度、形变、速度敏感性特征,其磨耗是一个相当复杂的过程。目前,对轮胎磨耗的研究仍然缺乏系统的理论成果可资应用,仍然面临诸多挑战。本研究立足应用、力求实效,聚焦轮胎磨耗研究的关键难点,进行了理论和实验研究,从橡胶摩擦磨耗影响要素的解析、数学建模到轮胎的热力学分析与磨耗迭代计算,形成了一套比较系统的轮胎磨耗分析方法。1.橡胶磨耗影响因素的解析利用LAT100磨耗试验研究了胎面橡胶磨耗对滑移角度、速度、负荷的依赖关系。磨耗对负荷存在幂函数关系。磨耗对角度则存在二种不同的函数关系:在角度较小时,磨耗与角度表现为幂函数关系,但角度较大时,采用指数函数拟合磨耗量与角度的关系比幂函数具有更高的精度,反映出磨耗对角度具有强烈的依赖性。速度对磨耗的影响主要体现为橡胶温度的变化,速度对磨耗的影响可以用温度来表征。基于Akron磨耗试验机,开发了对橡胶轮加热的高温磨耗测试辅助装置,研究了温度对橡胶磨耗的影响规律,温度对磨耗的影响可以用二次多项式来表征。橡胶磨耗是角度、温度、负荷、速度多因素交互作用的复杂过程。建立磨耗对多因素的综合解析式是困难的,各因素对于磨耗的重要程度一直是令人着迷而又困惑的问题。为此采用xgboost数据挖掘技术,对LAT100测试的三种TBR胎面胶的1000多组数据进行了整合分析,给出了角度、温度、速度、负荷及胎面胶配方5种因素对磨耗的影响权重,定量描述了各因素对磨耗的重要性。2.橡胶的摩擦特性自制了摩擦系数测试装备和多种路面,测试分析了低速下不同路面、不同负荷的摩擦系数,负荷对橡胶在粗燥表面的摩擦系数影响很小。利用LAT100测试数据,研究了摩擦系数与负荷、角度、温度、速度的关系。负荷对摩擦系数影响很小,这与低速下的测试结果相一致。温度、速度对摩擦系数的影响可用综合变量logatv来表征,摩擦系数与logatv存在二次多项式关系,在一定的温度范围内(如轮胎的正常使用温度),摩擦系数对温度、速度并不是十分敏感,这与许多学者认为“摩擦系数对温度、速度极其敏感”的观点相左。摩擦系数对角度非常敏感,摩擦系数的变化缘于角度引起的接地区域黏附和滑移的交互转化。为此引入黏附系数新参数,实现了摩擦系数对角度的表征。3.橡胶的磨耗模型(1)热力耦合模型负荷、角度与磨耗的关系可以集中用摩擦能来表征,温度、速度对磨耗的影响可以集中用温度来表征。磨耗对摩擦能存在幂函数关系。对lat100磨耗试验机进行了多工况的磨耗试验,用有限元模拟计算了不同工况的摩擦能,拟合得到了磨耗对摩擦能的幂函数关系式及幂指数和关系常数。磨耗对温度存在二次多项式关系。高温下的磨耗可以用温度和摩擦能二个变量来集中表征,得到考虑温度影响的摩擦能模型即磨耗的热力耦合模型。橡胶滞后生热导致的磨耗可被定义为橡胶的滚动磨耗,因此,橡胶的磨耗可看作滑动磨耗和滚动磨耗共同作用的结果。(2)橡胶磨耗的微观机理及本构表征磨纹的成因源于撕裂能聚集及由此导致的裂纹产生和扩展。采用分形几何中的盒维数法对橡胶磨纹特征进行了定量描述,综合分析了已有的典型微观解析模型的特点,提出了一种新的橡胶磨耗模型,给出了模量、生热、断裂能、磨擦系数与磨耗强度关系的综合表达式,为材料配方优化磨耗性寻求综合理论依据。4.轮胎的热力学分析轮胎的力学分析可以得到轮胎接地表面各单元的剪切摩擦应力和滑动位移,进而求得摩擦能,而接地表面各单元温度则可通过轮胎的温度场分析获得,由橡胶磨耗的热力耦合模型可进一步求解轮胎的磨耗量和磨耗高度。热力学计算的可靠性和精度直接影响磨耗分析的结果,是轮胎磨耗分析的重要环节。针对轮胎热力学仿真目前存在的关键理论及应用问题,如材料及理论模型的精度、材料测试精度、产品优化技术等亟待解决的问题,进行了研究探索。(1)结构力学分析建立了一套橡胶力学性能试验系统,通过该系统可以得到轮胎橡胶的材料性能参数。主要包括:实验设计、ccd图像处理、橡胶材料试验硫化模具设计、橡胶材料及钢丝骨架材料的测试等。采用该测试平台及试验测试数据对不同材料模型的精度进行了评估和优选。基于企业与高校联合开发的tysys结构力学分析软件,有机的融合最小应变能力理论、最小应力应变幅值、最佳接地形状、最佳应变能周期、最佳滚动轮廓等设计理论,引入区域应变能的概念,结合退赔分析、国外优秀产品的剖析及大量的机床试验验证,建立了产品有限元分析评价判断准则。以产品改进的算例阐述了有限元分析技术产业化应用的流程和重要性。该技术获得多项科技成果并产生巨大经济效益。(2)热学分析对材料(单质橡胶及橡胶/钢丝单层材料)热学关键参数的模型进行了梳理和细化,结合大量试验测试数据,对损耗因子及导热系数的温度依赖性进行了表征。考虑损耗因子、导热系数的非线性,对稳态非线性温度场的求解进行了理论推导。5.轮胎磨耗分析基于轮胎的热力学分析和橡胶磨耗模型,采用磨耗迭代计算的方法,研究了速度、负荷对轮胎轮廓及磨耗量的影响规律。速度对磨耗的影响主要体现为因其的轮胎滞后生热,滞后温升对磨耗有重要影响。由此可以看出建立磨耗的能量和温度的综合模型,即热力耦合模型是十分重要的。负荷增加会导致接地压力、摩擦力的增大及应力分布的变化,磨耗轮廓随着负荷的增大呈现中部减小、肩部增加的态势,磨耗量对负荷存在幂函数关系。负荷及温度对磨耗均具有重要影响,其规律与LAT100磨耗试验的结果相吻合,说明模拟分析结果是合理的。轮胎压力印痕的研究很具现实意义,也是磨耗研究的基础。其直接影响轮胎的耐磨性,并与轮胎的异磨、偏磨等不均匀磨耗密切相关。采用“TV7101轮胎接地压力分布测试分析系统”建立了轮胎压力印痕的测试及评价方法。该方法给出了矩形系数、不均匀度、压力梯度、负荷承担率、面积占有率等参数的定义和计算公式,能够实现对压力印痕的更为细致的定量评价,目前已被企业采用并形成企业技术标准。试验验证。轮胎的压力印痕可以通过结构设计参数的优化得以改善,压力印痕评价及有限元分析技术为轮胎结构设计的优化、优选提供了手段。以12R22.5产品改进为例,阐述了优化压力印痕提高耐磨性的过程。试验结果表明:改进后轮胎的平均接地压力降低了7.802%而装车里程试验耐磨性提高了20%,达到了2.5倍,与理论分析得到的磨耗对负荷的关系具有很好的一致性。
[Abstract]:Wear is a phenomenon of gradual loss of a material caused by mechanical or chemical reactions on the surface of an object. The friction occurs when the interaction of two objects is relative sliding between any of the objects under the existence of friction. The loss of material and the geometric shape of the two contact surfaces are the gradual characteristics of the friction. The dynamic process. The friction and force transmission of the tire and the ground provide the various forces and moments required for the motor vehicle movement. The tire is bound to cause the wear of the tire. The tire is a shell structure consisting of rubber and fiber or steel reinforced material, with a viscoelastic, large deformation, nonlinear and temperature, deformation, and speed sensitivity. The wear of the tire is a very complicated process. At present, the research on tire wear is still lack of systematic theoretical results and still faces many challenges. This study is based on the application of the research and focuses on the key and difficult points of the tire wear research. The theoretical and experimental research is carried out, and the factors affecting the friction wear of rubber are analyzed. Mathematical modeling to the thermodynamic analysis of tire and the iterative calculation of wear and wear, an analytical method of tire wear analysis in a relatively systematic way is formed in the analysis of the influence factors of.1. rubber wear. The dependence of the tire rubber wear on the slip angle, velocity and load is studied by the LAT100 wear test. There are two different functional relationships: the wear and the angle are power function relations at the lower angle, but when the angle is larger, the relationship between the wear and the angle is more accurate than the power function, which reflects the strong dependence on the wear angle. The influence of speed on the wear is mainly reflected by the rubber temperature. The influence of speed on wear can be characterized by temperature. Based on the Akron wear testing machine, a high temperature wear test auxiliary device for rubber wheel heating is developed. The influence of temperature on rubber wear is studied. The effect of temperature on wear can be characterized by two times polynomial. The rubber wear is the angle, temperature, load and speed. The complex process of factors interaction. It is difficult to establish the comprehensive analytical formula of wear to multiple factors. The importance of each factor to the wear is always a fascinating and puzzling problem. Therefore, the xgboost data mining technology is used to integrate the more than 1000 sets of data of three kinds of TBR tread of the LAT100 test and give the angle, The influence weight of 5 factors, temperature, speed, load and tread formula on wear, the importance of each factor to wear,.2. rubber's friction characteristics, the friction coefficient test equipment and many kinds of pavement are made. The friction coefficient of different pavement, different load at low speed and the friction system of the rubber on the rough surface are tested and analyzed. The influence of the number of numbers is very small. The relationship between the friction coefficient and the load, the angle, the temperature and the velocity is studied by using the LAT100 test data. The effect of the load on the friction coefficient is very small, which is in accordance with the test results at low speed. The influence of temperature and velocity on the friction coefficient can be characterized by a comprehensive variable logatv, and the friction coefficient has two polynomial relations with the logatv, and In a certain temperature range (such as the normal use temperature of a tire), the friction coefficient is not very sensitive to the temperature and speed, which is different from the viewpoint that many scholars believe that the friction coefficient is extremely sensitive to temperature and velocity. The friction coefficient is very sensitive to the angle, and the change of the friction coefficient is due to the adhesion and slip of the ground area caused by the angle. A new parameter of adhesion coefficient is introduced to realize the friction coefficient to the angle of the.3. rubber wear model (1) the thermal coupling model load. The relation between the angle and the wear can be characterized by the friction energy. The influence of temperature and velocity on the wear can be characterized by the temperature. The friction energy has a power function relationship. The wear test of lat100 wear tester is carried out in multiple working conditions. The friction energy of different working conditions is calculated by finite element method. The relation of power function and power exponent and relation constant of friction energy to friction energy are obtained. There are two polynomial relations between wear and temperature. The wear consumption at high temperature can be set by two variables, temperature and friction energy. The friction energy model, which considered the effect of temperature, is characterized by the thermal coupling model of wear, which is defined as the rolling wear of rubber. Therefore, the wear of rubber can be regarded as the result of the joint action of sliding wear and rolling wear. (2) the mechanism of rubber wear and the cause of the cause of the texture of the texture are derived from the cause of the cause of the wear pattern. The characteristics of the rubber wear are quantificationally described by the box dimension method in fractal geometry, and the characteristics of the typical typical micro analytical models are analyzed. A new rubber wear model is put forward, and the relation between modulus, heat, fracture energy, friction coefficient and wear strength is given. In order to find the comprehensive theoretical basis for the optimization of material formulation, a comprehensive theory based on the thermodynamic analysis of.4. tires can be used to obtain the shear friction stress and sliding displacement of each unit on the ground surface of the tire, and then the friction energy is obtained, and the temperature of the ground surface can be obtained by the analysis of the temperature field of the tire, and the rubber is obtained by the rubber. The thermal coupling model of rubber wear can further solve the tire wear and wear height. The reliability and accuracy of thermodynamic calculation directly affect the results of wear analysis. It is an important part of tire wear analysis. The key theory and application problems of tire thermodynamic simulation, such as material and theoretical model, are the precision of material and theoretical model. Test precision, product optimization technology and other problems to be solved. (1) structural mechanical analysis set up a set of rubber mechanical performance test system, through the system can get the tire rubber material performance parameters, including: experimental design, CCD image processing, rubber material test vulcanization mold design, rubber material The test platform and test data are used to evaluate and optimize the accuracy of different material models. Based on the tysys structural mechanics analysis software developed jointly by enterprises and universities, the organic fusion minimum strain ability theory, the minimum stress strain amplitude, the optimum grounding shape, and the optimum strain energy cycle are made. The concept of regional strain energy is introduced, the concept of regional strain energy is introduced, combined with the analysis of refund compensation, the analysis of foreign excellent products and a large number of machine tool test verification, the evaluation criteria of product finite element analysis and evaluation are established. The process and importance of the application of the finite element analysis technology industrialization are expounded with the example of product improvement. The technology is obtained. A number of scientific and technological achievements have been obtained and great economic benefits have been obtained. (2) thermal analysis of the thermal analysis of material (single rubber and rubber / steel wire single layer material) model of thermal key parameters was combed and refined, combined with a large number of test data, the loss factor and thermal conductivity of the temperature dependence were characterized. Linear, the theoretical derivation of the steady-state nonlinear temperature field is derived. The.5. tire wear analysis is based on the tire thermodynamic analysis and the rubber wear model. The influence of the speed and load on the tire profile and wear is studied by the method of wear iterative calculation. The influence of speed on the wear is mainly reflected by the lag generation of tire. Heat, the lag temperature rise has an important effect on wear and wear. Thus it is shown that a comprehensive model of the energy and temperature of wear, that is, the thermal coupling model is very important. The increase of load will lead to the ground pressure, the increase of friction force and the change of the stress distribution, the wear outline decreases with the increase of the load, the increase of the shoulder and the grinding of the shoulder. The load and temperature have an important influence on the load. The load and temperature have an important influence on wear and wear. The rule is in agreement with the results of the LAT100 wear test. It shows that the simulation analysis results are reasonable. The research on tire pressure mark is very practical and the foundation of Wear Research. The measurement and evaluation method of tire pressure marks is established by using the "TV7101 tire ground pressure distribution test and analysis system". The method gives the definition and calculation formula of the parameters such as the rectangular coefficient, the inhomogeneity, the pressure gradient, the load bearing rate, the area occupancy and so on. It can realize the pressure mark. The more detailed quantitative evaluation has been adopted by the enterprise and formed the technical standard of enterprise. Test verification. The tire pressure marks can be improved through the optimization of structural design parameters. Pressure mark evaluation and finite element analysis technology are used to optimize the design of tire structure and provide a means to optimize the design of the tire. The 12R22.5 product improvement is illustrated as an example. The test results show that the average ground pressure of the improved tire is reduced by 7.802% and the wear resistance of the loaded mileage test is increased by 20%, reaching 2.5 times, and the relationship between the wear and the theoretical analysis is in good agreement with the load.
【学位授予单位】：青岛科技大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TQ336.1
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本文编号：1930885