汽车行驶时悬架系统承受着来自路面的载荷冲击，保证其耐久性是汽车设计中非常重要且急需解决的关键问题之一，多轴向加载的室内道路模拟疲劳试验被广泛采用。为了进一步缩短汽车研发周期，降低研发成本以提高市场竞争力，该文建立了后驱动桥的动态有限元模型，依照实验室道路模拟疲劳试验的基本原理，通过编制MATLAB程序实现了系统频响函数识别、根据目标信号和频响函数反求动态载荷、计算动态响应与目标信号的误差等功能。仿真结果表明：后驱动桥目标信号测点的应力应变时间历程复现综合误差均在5%以内，并预测出该悬架系统的疲劳强度危险点位于截面尺寸突变的区域。
When a vehicle is running, its suspension is heavily loaded due to the motion. The durability is then one of the key problems in vehicle design. Multi-axial loading laboratory fatigue tests are widely used to shorten the development process, reduce costs and enhance market competitiveness. This paper presents a practical method for simulating multi-axial fatigue tests of a rear axle using a dynamic finite element model of the rear axle and data processing in MATLAB. The simulation of the laboratory fatigue tests includes system identification, calculation of the input dynamic loads for the finite-element model and calculation of the stress-strain response reproduced and compared with the measured stress-strain response. With the errors of less than 5% with the critical fatigue areas in the rear axle located where the section sizes change.
[1] JACOBY G. Betriebslastensimulation an fahrzeugbauteilen mittels servohydraulischer prüfeinrichtungen[J]. VDI-Berichte, 1987:1-54.[2] WHITE K J. The road simulator-a practical laboratory approach. Prediction and simulation of in-servcice conditions[C]//Proceedings of the Conference Held at the Institution of Mechanical Engineers. Washington, DC, USA:Mechanical Engineering Publications Limited, 1985:69-80.[3] FEITZELMAYER K, BREITLING U. Development of commercial vehicle rear driven axles on multi-axis test set-ups:Prediction and simulation of in-service conditions[C]//Proceedings of the Conference Held at the Institution of Mechanical Engineers. Washington, DC:Mechanical Engineering Publications Limited, 1985:131-138.[4] DODDS C J. A computer system for multi-channel remote parameter control of a test specimen[Z]. Forney:MTS Publication, 1977.[5] 王霄锋. 汽车可靠性工程基础[M]. 北京:清华大学出版社, 2007. WANG X F. Fundamentals of automotive reliability engineering[M]. Beijing:Tsinghua University Press, 2007. (in Chinese)[6] Anon. Simulation testing and SPiDAR-IDC[Z]. Forney:Fairhurst Structural Monitoring Publication, 1987.[7] DE CUYPER J, COPPENS D, LIEFOOGHE C, et al. Advanced system identification methods for improved service load simulation on multi-axial test rigs[J]. European Journal of Mechanical & Environmental Engineering, 1999, 44:27-39.[8] DE CUYPER J, COPPENS D. Service simulation on multi axis test rigs[J]. Sound and Vibration, 1999, 30(1):30-35.[9] KANG D, HEO S, KIM H. Virtual road profile modeling using equivalent damage method for VPG simulation[J]. SAE Technical Paper, 2009, 2009-01-0814.[10] 曹正林, 李骏, 郭孔辉. 基于虚拟试车场的轿车悬架耐久性强化试验仿真研究[J]. 机械工程学报, 2012, 48(10):122-127. CAO Z L, LI J, GUO K H. Research on passenger car suspension durability using virtual proving ground[J]. Journal of Mechanical Engineering, 2012, 48(10):122-127. (in Chinese)[11] FRICKE D, FROST M. Development of a full-vehicle hybrid-simulation test using hybrid system response convergence (HSRC)[J]. SAE International Journal of Passenger Cars-Mechanical Systems, 2012, 5(2):921-936.[12] YOU S, JOO S G. Virtual testing and correlation with spindle coupled full vehicle testing system[J]. SAE Technical Paper, 2006, 2006-01-0993.[13] YOO S S, Fricke D. Advances of virtual testing and hybrid simulation in automotive performance and durability evaluation[J]. SAE International Journal of Materials and Manufacturing, 2011, 4(1):98-110.[14] DOWLING N. A discussion of methods for estimating fatigue life[J]. SAE Technical Paper, 1982, 820691.[15] REEMSNYDER H. Constant amplitude fatigue life assessment models[J]. SAE Technical Paper, 1982, 820688.[16] SOCIE D. Variable amplitude fatigue life estimation models[J]. SAE Technical Paper, 1982, 820689.
