【作者】 姚曙光；

【导师】 田红旗；

【作者基本信息】 中南大学 ， 载运工具运用工程， 2010， 博士

【摘要】 重载运输是铁路提高大宗重质货物运输能力的主要技术手段,提高车辆轴重、增大车辆载重是发展重载运输的重要举措。在保证结构强度、刚度和稳定性满足要求的前提下,实现车体结构的轻量化是车体结构设计的首要问题。本文围绕研制目前世界上轴重最大40吨、自重系数最小0.16、调车允许安全连挂速度不低于9.5km/h、能承受5560kN纵向冲击载荷的重载敞车车体结构开展研究,形成一套铁路车辆结构非线性分析方法。研发了多车耦合调车冲击数值仿真程序。冲击是导致车辆损坏的重要原因之一,针对重载货车的调车安全连挂速度开展研究,建立经调车冲击试验得到的车钩缓冲器阻抗特性曲线,运用多体系统动力学理论,在ADAMS平台上开发了多车耦合调车冲击数值仿真程序。进行了5km/h以上不同调车冲击速度下,1节车对1节车、1节对3节车以及2节对2节车3种调车冲击动力特性研究,得到车钩缓冲器容量大小对冲击动能耗散影响的定量结果,提出重载货车调车冲击安全连挂速度限值。提出了铁路重载货车材料与几何结构非线性分析方法。重载车辆既需提高车辆轴重,又要降低车辆自重增大载重,单靠传统的线性结构分析方法已无法满足,需要在其计算的基础上,进一步采用非线性结构分析方法。提出重载货车结构设计按结构不失稳并允许产生局部塑性变形的原则进行,利用金属材料的强化性能,允许结构局部塑性变形并控制其扩展,以提高结构的整体承载能力,采用材料非线性理论完成车体结构冲击强度分析；应用几何非线性理论,对板梁组合的薄壁整体承载车体结构进行了屈曲稳定性分析。根据分析结果,提出了车体结构强度、刚度调整优化措施,完成了轴重40吨、车体结构自重8.36吨、材质为Q450NQR1的重载敞车车体结构的优化设计,产品已批量生产并投入实际运用,表明非线性结构分析方法是重载车辆结构优化设计的有效手段。针对纵向冲击作用下散粒货物的流动大变形特性,提出用任意拉格朗日-欧拉方法描述散粒货物的运动,进行纵向冲击下车体结构动强度分析的方法。该方法包括了散粒货物用ALE方法描述,车体结构用拉格朗日方法描述,流固耦合力学模型的创建,以及采用中心差分显式时间积分法、拉格朗日和欧拉算法相结合的算子分离技术实现ALE控制方程的求解。对纵向冲击下的车体结构进行了动强度分析,得到散粒货物的运动特性和车体结构的动力响应,解决了冲击过程中散粒货物不断前涌,如何求解冲击端端墙压力的难题。提出了铁路重载货车结构材料轻量化、低阻力车体。敞车侧墙立柱设计成内置,保持侧墙外壁平整,降低列车运行阻力；把耐腐蚀新材料NIROSTA(?)T4003不锈钢材质用于与矿石接触的部件,进一步降低车体自重,并减少车体的维护；结合自行编制的车体结构轻量化程序,进行了敞车车体结构的轻量化研究,使40t轴重不锈钢敞车载重为138吨的车体结构自重仅为7.02t。更多还原

【Abstract】 Railway heavy haul transport is the main technological way to improve the transport capacity of large cargoes. And increasing the axle-weight of vehicle and improving the load of vehicle are important measures to develop the railway heavy haul transport. On the premise that the structure strength and stiffness of vehicle meet the requirements, it is a primary issue that the weight of vehicle structure has to be reduced.This paper focused on the research of the body structure of heavy load gondola car which holds the heaviest axle load that is 40 tons, the least self-weight coefficient that is 0.16, the speed coupling of shunting vehicles which is less than 9.5km/h and withstands the longitudinal impact load of 5560kN. A set of nonlinear analysis of railway vehicle was systematically proposed. Numerical simulation system about impact of multi-vehicle coupling shunting was developed. Impact is one of the important causes which lead to the damages of vehicles. Aims at the safety coupling speed of shunting vehicles of heavy haul freight cars, the impedance curve about coupler buffer which was gotten from the shunting impact tests was presented. Numerical simulation programs about impact of multi-vehicle coupling shunting were developed on the platform of ADAMS based on the multi-body system dynamics theory. Dynamic impact characteristics of three different kinds of shunting operations that was one segment vehicle to one segment, two segment vehicle to two and three segment vehicle to three were studied under different shunting impact speeds conditions that were all above 5km/h. The quantitative results were obtained, which can describe the influence coupler buffer capacity with the size of the impact kinetic energy dissipation. And the safety coupling speed of shunting vehicles of heavy haul freight car was proposed.In addition, a series of nonlinear analysis methods for heavy haul freight cars and geometric structures were presented. As for the heavy vehicles, not only the axle-weight should be improved, but also the deadweight should be lightened and the load should be increased to improve their performances. However, the traditional linear elastic structure design methods for Chinese railway vehicles can’t meet the demands. Based on the previous results, the further analysis of the nonlinear structure has to be done. The structure of the heavy haul freight car is designed on the principles that the structure is stable and local plastic deformation is allowed. With the utilization of the material hardening property, the local plastic deformation of the structure was allowable and its expansion was controlled to enhance the whole bearing capacity. The impact strength of body structure was analyzed based on the material nonlinear theory. The buckling analysis on the thin-walled whole bearing body structure, which was the combination of plate and beam, was carried out based on the geometric nonlinear theory. From the analysis results, the adjustment and optimization measures of body structure strength and stiffness were proposed. And the body structural optimal design of heavy load gondola car, of which axle load was 40 tons, body structure weight was 8.36 tons and material was Q450NQR1, was done. The products have been put into general production and practical application, which show that the nonlinear structural analysis method is an effective way of the structural optimal design of heavy vehicle.For the flow large-deformation characteristics of bulk goods under the longitudinal impact, using Lagrange_Euler method to describe the bulk goods’motion, the dynamic strength analysis method of body structure under the longitudinal impact was proposed firstly. It consists of the description of ALE Equations of bulk goods, the description of Lagrangian Equations of body structure, the establish of fluid and solid coupled mechanics model and the solving equations for ALE separation technology with the combination of central difference explicit time integration method, Lagrange and Euler algorithm. The dynamic strength analysis method of body structure under the longitudinal impact of different speeds was carried out to obtain the movement characteristics of bulk goods and the dynamic response of the body structure. The problem of the bulk goods flowing out in impact process and how to compute the wall pressure of impact side were solved. Railway heavy haul wagon body of low resistance, lightweight of structure and material was designed. The flat outside sidewall surface with the inner sidewall post can reduce the train running resistances. Besides, the new stainless steel comprised of NIROSTA(?)4003 materials with corrosion resistance was used to manufacture the parts that are with the ore directly. This optimization can further reduce the deadweight and maintenance cost. Based on the private software of car structure lightweight, the study on how to lighten the body structure of gondola car was finished which makes the deadweight of body structure of stainless Steel wagon of 40t axle and 138 tons load is only 7.02 tons.更多还原