【作者】 李韶华；

【导师】 杨绍普；

【作者基本信息】 北京交通大学 ， 车辆工程， 2009， 博士

【摘要】 随着公路交通的迅猛发展和运输向重型化发展,由于汽车动载引起的路面早期破坏已成为突出问题。路面的早期破坏,反过来又会引起汽车的振动加剧,严重影响行车的安全性、舒适性,并进一步加大汽车对路面的动载。因此,汽车与路面是一个相互作用相互耦合的系统。但是,目前汽车动力学和路面动力学将汽车和路面作为两个独立的系统进行研究。汽车动力学将路面作为汽车系统的激励,研究汽车的动力响应和参数优化。路面动力学将汽车作为对路面的移动载荷,研究路面的动力响应和使用寿命。本文力图通过轮胎动载把汽车模型和路面路基模型相联接,建立汽车-路面—路基耦合系统,并基于此耦合系统同时研究汽车和路面的动力学行为。轮胎与路面作用力分别采用点接触模型和本文提出的改进弹性滚子接触模型,汽车路面特性分别考虑线性和非线性,路面材料分别考虑弹性和粘弹性两种情况。通过积分变换法、模态叠加法和直接数值积分研究线性车路系统的动力响应,通过伽辽金方法、平均法、多尺度法、Melnikov方法和数值仿真研究非线性车路系统的动力响应。将轮胎点接触模型和改进弹性滚子模型、车路耦合模型与传统模型进行了对比。全面分析了车路系统参数对汽车乘坐舒适性及道路疲劳破坏的影响,提出了车路系统参数的低动力设计措施。研究发现,本文提出的路面二次位移激励可反映轮胎动载的空间重复性分布规律;改进弹性滚子轮胎模型计算的脉冲响应比点接触模型更接近实测数据;车路耦合作用与汽车载重、路基刚度及路面不平顺幅值密切相关,汽车载重越大、路基刚度和路面不平顺越小,车路耦合作用越明显;车速、面层、基层密度对车路响应的影响呈波动规律;减小汽车载重、轮胎质量、轮胎刚度、悬架刚度,增大路基阻尼,既可提高乘坐舒适性又可减小路面破坏;车路非线性对车体垂向加速度的影响较大,对路面垂向位移的影响较小;路面材料的粘弹性对车体垂向加速度的影响非常小,对路面垂向位移的影响较大,粘弹性材料的路面响应大于弹性材料的路面响应。更多还原

【Abstract】 With rapid development of highway transportation and increase of vehicle loads,the early damage of pavement on expressway caused by vehicle dynamical tire forces is more and more serious.The road damage leads to vehicle vibration increase,which may reduce the vehicle’s driving safety and riding comfort.As a result,dynamical tire forces increase greatly.Thus the vehicle and pavement are interacted and coupled.Howerver,the vehicle and pavement are investgated seperately in vehicle dynamics and pavement dynamics.In vehicle dynamics,the road surface roughness is regarded as excitation to vehicle,and the dynamical behavior and the parameter optimization of the vehicle are investigated.In pavement dynamics,the vehicle is regarded as moving loads acting on pavement,and dynamical responses and life span of pavement are investigated.In this dissertation,the vehicle model,pavement model and foundation model are linked to a great vehicle-pavement-foundation coupled system by dynamical tire forces. Based this coupled system,dynamics of vehicle and pavment are researched simulately. The dynamical tire forces are computed by traditional point contact model and the revised flexible roller contact model proposed by this dissertation.The linear vehicle and pavement,and the nonlinear vehicle and pavement are studied.The elstic and viscoelastic pavement material are considered.By methods of integral transformation, mode superposition and direct integral,responses of linear vehicle-pavement system are researched.By methods of Galerkin,averaging,multi-scale,Melnikov function and numerical simultaion,responses of nonlinear vehicle-pavement system are researched also.Dynamical responses of traditional point contact tire model and the revised flexible roller contact tire model,traditional system and coupled system are compared respectively.The effect of parameters of vehicle and pavement on vehicle riding comfort and road damage are analyzed detailedly and measures of parameters’ low -dynamic design are concluded.It is found that the second road displacement excitation proposed in this work is able to reflect spacial repeatability of dynamic tire forces;the impulsive reponse obtained by the revised elastic roller contact tire model is more close to test data than the point contact tire model;the coupling action between vehicle and pavement depends on vehicle load,foundation stiffness,and amplitude of road surface roughness;with increase of vehicle load,foundation stiffness,or amplitude of road surface roughness, the coupling action become more obvious;the effect of vehicle running velocity and pavement density on vehicle riding comfort and road damage is fluctuate;Decrease of vehicle load,tire mass,tire stiffness or suspension stiffness,or increase of foundation damping is benefit to both vehicle riding comfort and control of road damage;the effect of nonlinearity of vehicle and pavement on vehicle body vertical acceleration is bigger than that on pavement vertical displacement;the effect of viscoelasticity of pavement material on vehicle body vertical acceleration is smaller than that on pavement vertical displacement and responses of pavement with viscoelastic material are bigger than that of pavement with elastic material.更多还原