基于有限元分析的越野汽车车架结构优化
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。
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.
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。
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.
引文
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[2]梅飞.计算机辅助工程技术发展及应用综述.滁州学院学报.2007,9(3)：45-47
[3]张铁山.胡建立.唐云CAD/CAE技术在汽车车架设计中的应用.上海工程技术大学学报,2001,15(3)：216-220
[4]黄金陵.有限元法应用于汽车车架结构分析中的几个问题.吉林工业大学学报,1980(1)：76-88
[5]谷安涛,常国振.汽车车架设计计算的有限元法.汽车技术,1977,(06)：54-65
[6]李美芳.CAE技术及其发展趋势.世界制造技术与装备市场,2005,(04)：82-83
[7]杨朝丽.计算机辅助工程(CAE)发展现状及其应用综述.昆明大学学报,2003,(2)：50-54
[8]杨鼎宁,邹经湘,盖登宇.计算机辅助工程(CAE)及其发展.力学与实践,2005,27(3)：7-15
[9]朱龙.计算机辅助工程(CAE)技术的应用及其新发展.机械制造与自动化.2004,33(6)：7-8
[10]孙海霞,刘大维,严天一,陈焕明,程晓东.公矿自卸车车架结构强度有限元分析.现代设计与先进制造技术,2007,36(3)：33-36
[11]翁江翔,张显悦.NQ6021型车身车架静态强度模拟计算分析.交通科技与经济,2007,9(6)：49-50
[12]柴苍修,马力,王元良,李春光.农用运输车车架有限元强度的分析.拖拉机与农用运输车,2002,(1)：14-18
[13]苏庆,孙凌玉,刘福保.运用CAE技术进行某微型客车车架结构的分析与优化设计.农业装备与车辆工程,2005,(4)：26-32
[14]武和全,辛勇,董学勤.某越野车车架有限元建模与刚度分析.机械设计与制造,2008,(6)：15-17
[15]马迅,盛勇生.车架刚度及模态的有限元分析与优化.客车技术与研究,2004,26(4)：8-11
[16]叶青,李宇彤,赵黎,李锋NHQ6470EG2Y型汽车车架扭转刚度的测试研究.汽车技术，2006,(7)：24-27
[17]谢世坤,程从山.基于ANSYS的边梁式车架有限元模态分析.机电产品开发与创新,2005,18(1)：76-78
[18]牛跃文.识别车架动态性能的有效手段—矿用汽车车架有限元模态分析.MC现代零部件,2007,(6)：86-87
[19]张胜兰,严飞.基于Hyper Works的车架模态分析.机械设计与制造,2005,(4)：10-1 1
[20]刘大维,严天一,董振国,刘青云,陈秉聪.自卸汽车车架模态试验与分析.河南科技大学学报(自然科学版),2006,27(4)：30-32
[21]曾桂香,李中华,胡少伟.模态试验分析在汽车车架故障诊断中的应用.拖拉机与农用运输车,2007,34(3)：87-89
[22]刘开宇.自卸车裂纹产生的原因及结构改进.应用技术,2006,(4)：61-62
[23]李德信,吕江涛,应锦春.SX360自卸车车架异常断裂原因分析.汽车工程,2002,24(4)： 348-352
[24]严辉俊,黄贵东,黄昶春,韦志林,沈光烈.重型自卸车车架早期断裂原因的研究.汽车工程,2006,28(12)：1133-1135
[25]周志革,王金刚,崔根群,武一民,杜喜然.轻型货车车架纵梁异常开裂原因的分析.汽车工程,2004,26(2)：229-232
[26]Silva, M.M.D., Oliveira, L.P.R., Neto, A.C., Varoto, P.S. An Experimental Investigation on the Modal Characteristics of an Off-Road Competition Vehicle Chassis. Sao Paulo, Brazil, SAE Technical Paper Series No.2003-01-3689
[27]Filho,R.R.P.,Rezende,J.C.C., Leal, M.D.F., Borges, J.A.F. Automotive Frame Optimization. Sao Paulo, Brazil, SAE Technical Paper Series No.2003-01-3702
[28]Zzman, I.B., Rahman, R.A. APPLICATION OF DYNAMIC CORRELATION TECHNIQUE AND MODEL UPDATING ON TRUCK CHASSIS, Proceeding of 1st Regional Conference on Vehicle Engineering and Technology,2006, Putra World Trade Centre (PWTC)
[29]Fui, T.H., Rahman, R.A. STATICS AND DYNAMICS STRUCTURAL ANALYSIS OF A 4.5 TON TRUCK CHASSIS. Journal Mekanikal,2007,24:56-67
[30]Choi, Y., Yeo, H.T., Park, J.H., Oh, G.H. A study on press forming of automotive sub-frame parts using extruded aluminum profile, Journal of Materials Processing Technology, 2007, vol.187-188,pp.85-88
[31]Lee, H.Y., Seo, H., Park, G.J. Design enhancements for stress relaxation in automotive multi-shell-structures. International Journal of Solids and Structures,2003,40:5319-5334
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