【作者】 程思远；

【导师】 王文林；

【作者基本信息】 南昌大学 ， 车辆工程， 2010， 硕士

【摘要】 以陆风X6型越野汽车为研究对象,针对其车架容易出现裂纹和裂纹疲劳扩展的问题,借助CAE方法展开了一系列分析工作,并在这些分析结果的指导下对该车架进行了结构优化设计。运用UG软件建立了该车架的三维实体模型,运用HyperMesh软件对此三维模型进行几何清理、中面抽取、网格划分和悬架焊接模拟等前处理,从而建立了完整的、质量较高的车架有限元分析模型,最后将此有限元模型导入到ANASYS中进行分析。通过实验模态分析验证了理论模态分析结果,从而也验证了所建立有限元分析模型的正确性和准确性。后续CAE分析结果表明：陆风X6越野汽车车架产生裂纹的主要原因是其悬架摆臂支座与纵梁的连接处和扭杆弹簧锚定支座与纵梁的连接处设计不合理,由此造成了局部应力集中以及车架整体扭转刚度不足,因此在越野情况下车架很容易产生裂纹和裂纹疲劳扩展。采用动态应力抵消的方法对该车架进行了结构关联优化设计。进一步分析表明：该方法不仅消除了车架的局部应力集中,同时还有效提高了车架的整体扭转刚度和疲劳强度,提高了车架的整体使用性能。陆风X6越野汽车车架按照本文的方法进行改进后,其大量的道路试验和市场反馈表明：该车架改进合理、实用,达到了预期的目的,并且该方法继续应用在新车型陆风X8的车架设计中。更多还原

【Abstract】 Taking Landwind X6 sport utility vehicle as the research object, this paper conducts a series of analysis with CAE method to the crack and crack fatigue expanding defects which appears in the chassis and then optimum structural design of the frame is carried out with the results of analysis.First, establish 3D solid model of the chassis with UG software; second, carry out a series of preprocess, such as cleanup geometry, extracting mid-surface, meshing, simulating weld of the suspension to establish a complete and high-quality finite element model of the frame; last, import the finite element model to analyze with ANSYS. The results of the theoretical modal analysis are verified by experiments; therefore the finite element model established is proved to be correct and exact. The results of the subsequent analysis shows that the main cause of the crack appearing in the frame of Landwind X6 off-road vehicle is the unreasonable design, which lies in not only the joint of the suspension arm support and the carling but also the joint of anchoring support of the torsion-bar spring and the carling, the local stress concentration and the insufficient torsional rigidity of the whole frame are caused by this, as a result, the crack and crack fatigue expanding defects appear easily under off-road conditions.The optimum design of structure relevance is carried out by the method of dynamic stress offset. Further analysis shows:this method not only eliminates the local stress concentration of the chassis but also increases the torsional rigidity of the whole chassis and the fatigue strength effectively. In this way, the unitary usability of the chassis is increased.After the frame of the Landwind X6 off-road vehicle is improved according to this method, a lot of road tests and market feedback indicate:the improvement of this frame is reasonable and practical, which reaches its anticipatory aim and this method is applied in the design of new model of Landwind X8.更多还原