摘要
以地铁底架设备安装座铝合金焊缝为研究对象,采集线路实际运行过程中的加速度激励,基于疲劳损伤谱(fatigue damage spectrum, FDS)理论,提出一种非高斯激励的加速方法。首先计算实测输入信号的峭度、偏斜度,以此检验输入信号的非高斯分布特性,结果表明所有任务段激励均服从非高斯分布。为每个任务段激励选择合适的FDS计算方法,设置加速参数,基于损伤等效原则构建加速功率谱密度(power spectral density, PSD),以此作为后续台架试验的激励输入。建立有限元模型,计算支架焊缝加速疲劳寿命。开展台架振动试验,进行验证。试验与仿真疲劳寿命进行对比,结果表明其加速疲劳寿命相对误差为0.57%,加速比达到21 722.26,加速有效,该方法编制的加速PSD激励可以在5 h内反映支架安装座30年的服役情况。为车辆其他设备加速谱的编制提供参考。
Taking the aluminum alloy weld of the installation seat of a subway underframe as a research object and collecting the acceleration excitation during the actual operation of the line, an accelerating method for non-Gaussian excitation was proposed based on the theory of fatigue damage spectrum(FDS). The kurtosis and skewness of measured input signals were calculated to verify the non-Gaussian distribution characteristics of the input signals. The results show that all the excitation in the task segment obey the non-Gaussian distribution. Appropriate FDS calculation methods were selected for each task segment excitation, and the acceleration parameters were set. The accelerated power spectral density(PSD) was constructed based on the damage equivalence principle, which was then used as the excitation input in subsequent bench tests. A finite element model was established to calculate the accelerated fatigue life of bracket weld. Bench vibration tests were carried out to verify the numerical results. Comparing the fatigue life by the test and the simulation results, it is shown that the relative error between the accelerated life and the design service life is 0.57%, and the acceleration ratio reaches 21 722.26. The accelerated PSD incentive compiled by this method can reflect 30 years of service within 5 hours. At the same time, it provides a reference for the compilation of the acceleration spectrum of other equipments of vehicles.
作者
陈宽裕
阳光武
肖守讷
杨冰
朱涛
王举金
CHEN Kuanyu;YANG Guangwu;XIAO Shoune;YANG Bing;ZHU Tao;WANG Jujin(State Key Laboratory of Traction Power,Southwest Jiaotong University,Chengdu 610031,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2022年第22期253-259,共7页
Journal of Vibration and Shock
基金
中国航空科学基金(20180241001)。
