汽车前保险杠随机振动疲劳分析与优化设计  

Random Vibration Fatigue Analysis and Optimization Design of Automobile Front Bumper

作　　者：贾慧芳[1] 黄晖[1] 邱祖峰 Jia Huifang;Huang Hui;Qiu Zufeng(Jiangling Motors Corporation Limited Company,Nanchang 330200,China)

机构地区：[1]江铃汽车股份有限公司,江西南昌330200

出　　处：《工程塑料应用》2023年第9期63-68,共6页Engineering Plastics Application

摘　　要：为了识别某汽车前保险杠随机振动性能的风险,首先搭建前保险杠离散化模型,基于约束模态仿真得到其前三阶固有频率分别为32.6,41.1,53.3 Hz,均高于外界激振频率,满足动态特性要求,并且对其进行模态试验,测试结果表明其前三阶模态仿真误差分别为1.2%,2.2%,3.2%,均在实际工程允许范围之内,有效验证了有限元建模及分析具有较高的准确度。然后基于单位激励的频率响应获取其在X,Y,Z向应力传递函数,得到其最大振动应力值分别为10.6,8.293,15.73 MPa。再根据功率谱密度函数求解其随机振动疲劳,得到其最大疲劳损伤为0.5757,其薄弱点位于前保险杠下端的安装孔处,符合设计标准。最后基于集成平台并采用多岛遗传算法对其厚度进行优化迭代,得到了最佳的参数,其质量成功减轻了9.38%,优化之后前保险杠的第一阶频率为30.3 Hz,其疲劳损伤为0.8952,达到了疲劳性能与质量的最优匹配,并通过了整车路试验证。该研究技术为同类结构的性能开发与优化设计提供了有益参考,能够有效降低生产成本和指导实际制造过程。Aiming at identifyng the random vibration performance risks of automobile front bumper,the discretization model of front bumper was establish firstly,its first three natural frequency were 32.6,41.1,53.3 Hz based on constraint modal analysis,they were higher than the external excitation frequency,so it could meet vibration performance requirements,and it was modal tested.The test results show that first three orders of modal simulation error are 1.2%,2.2%,3.2%,they are within the limits allowed for the actual work,the high accuracy of finite element modeling and analysis is verified.Secondly,the stress transfer function of X,Y and Z direction were obtained based on the frequency response of the unit excitation,the maximum vibration stress values were obtained as 10.6,8.293,15.73 MPa.Thirdly,its random vibration fatigue was solved according to the power spectral density function,its maximum damage value was 0.5757,its weak point was located at the lower front bumper mounting holes,so it could meet the design standard.Lastly,its thickness were optimized iterated based on an integrated platform by adopting of multi-island genetic algorithms,the optimal parameters were obtained,its weight was reduced by 9.38%,its first order frequency was 30.3 Hz after optimization,its damage value was 0.8952,the optimal matching of fatigue performance and weight was achieved,and it had passed the real vehicle road test verification.This research technique provided the useful reference for the performance development and optimal design of similar structures,it could effectively reduced production costs and guided the actual manufacturing process.

关 键 词：前保险杠 模态 激励 频率响应 随机振动疲劳 优化 

分 类 号：TQ320.6[化学工程—合成树脂塑料工业] TP391.7[自动化与计算机技术—计算机应用技术]