【作者】 邓锐；

【导师】 翟婉明；

【作者基本信息】 西南交通大学 ， 车辆工程， 2008， 硕士

【摘要】 长期以来,构架作为铁道机车车辆系统的关键部件,其结构强度和疲劳寿命得到了广泛的关注。构架结构静强度在设计阶段可以通过计算,并结合相关理论进行评估从而得到保证。构架在动应力作用下的疲劳强度评估一般只有在其制造完成后,通过相应的疲劳测试试验来进行。如果测试结果表明构架的疲劳强度不满足设计和服务年限的要求,那么该构架就只得进行改进或重新设计。这显然与尽可能地缩短产品开发周期、最大限度地降低产品研制成本的现代化工业设计理念不符合。本文结合国内外疲劳研究最新成果,通过机车多体系统动力学仿真、有限元法和疲劳寿命预测等多领域综合分析,以期实现设计阶段机车转向架构架的疲劳寿命评估。首先根据机车实际的结构参数,利用动力学仿真软件SIMPACK建立整车动力学模型,通过对机车典型运行工况下的动力学性能仿真,计算得出用于构架疲劳寿命分析的载荷时间历程;然后根据机车转向架构架的实际结构尺寸,利用三维制图软件SolidWorks建立详细的构架实体模型,并利用该软件与ANSYS之间的接口实现构架的有限元分析,包括静态应力分析、准静态应力分析和模态分析;最后确定母材和焊缝的S-N曲线,结合作用于构架上的载荷时间历程和有限元准静态应力分析结果,选择合适的疲劳寿命预测方法,采用相关疲劳寿命分析软件nSoft对构架进行疲劳寿命分析,得出构架结构最薄弱的结构部位,并对其进行详细的寿命分析。这种基于虚拟样机技术的疲劳寿命分析方法,在构架结构设计阶段就能预测动应力分布状态,从而为构架结构的优化设计提供理论依据。更多还原

【Abstract】 For a long time, bogie frame as a key structural component of railway vehicle system, the structural strength and fatigue life are widely concerned. The intensity of a frame can be ensured by the calculation combining with the corresponding theory at the design stage. The frame fatigue life assessment under dynamic loads is done by adopting fatigue test only after the completion of the manufacture. If the testing results show that the fatigue strength of this type frame doesn’t satisfy design requirement or service life, the frame should be improved or redesigned. It’s obviously incompatibe with modern design concepts which must shorten product development cycles and minimize the manufacturing cost.Based on the latest fatigue research results at home and abroad, the paper is to achieve the locomotive bogie frame fatigue life assessment via the Multi-Body system dynamic simulation, the finite element method and fatigue life prediction at the design stage. Firstly, the whole locomotive dynamic model was established using the SIMPACK software according to the actual structural parameters. All the load histories, which were used to evaluate the bogie frame fatigue life, would be obtained by the dynamic performance simulation under the typical locomotive operation condtions. Secondly, the solid model of the frame was established using the 3D software SolidWorks. The finite element analysis of the frame was achieved through the connection between the 3D software and ANSYS software, including the static stress analysis, quasi-static stress analysis and modal analysis. Finally, combining the S - N curves of the material and weld, the load histories acting on the frame and the results of the quasi-static stress analysis, choosing the appropriate fatigue life prediction method, the frame fatigue life evaluation was done using the nSoft software. The most weakness position was confirmed and then the particular fatigue life analysis was done.The above fatigue life prediction method based on the virtual techinique can predict the stress distribution at the design stage and provide the theory instruction for the structural optimization of the frame.更多还原