摘要
很多机械结构在工作环境下经受的随机载荷有着较强的非高斯性,按照传统的高斯假设对这些结构进行疲劳计算会带来很大误差。针对非高斯载荷下结构疲劳寿命难以预测的问题,提出了一种非高斯随机载荷下对结构进行疲劳计算的频域方法。首先引入高斯混合模型(Gaussian mixture model,GMM)对载荷进行描述,并使用期望最大(expectation maximization,EM)算法对模型参数进行求解,建立的模型可以准确描述单峰及多峰非高斯载荷。在此基础上结合Tovo-Benasciutti方法推导出一种多峰非高斯载荷下的频域疲劳计算方法。为了对该方法进行验证,对一个双峰分布的非高斯载荷信号进行了疲劳分析,以雨流计数法作为参考,结果表明在双峰非高斯载荷下,对多种材料,该方法与直接使用传统频域疲劳计算方法相比计算精度提升明显,验证了该方法的精确性及较广的适用性。
The random load of many mechanical structures in the working environment has obvious non Gaussian characteristics.According to the Gaussian hypothesis,the fatigue calculation of these structures will bring great error.Aiming at this problem,a frequency domain method for fatigue life estimation under non-Gaussian random loading was established in this paper.A Gaussian mixture model(GMM)was introduced for describing the non-Gaussian load,and the expectation maximization(EM)algorithm was used to estimate the parameters of the model.Based on the obtained model,the uni-modal and muti-modal non-Gaussian load can be described accurately.Then combined with the Tovo-Benasciutti method,a vibration fatigue life estimation method was raised.A bi-modal load example was analyzed to test the accuracy of the method.Taking the rainflow counting method as a reference,results show that under bimodal non-Gaussian loads,for a variety of materials,compared with the traditional frequency domain fatigue calculation method,the calculation accuracy is significantly improved,which verifies the accuracy and wide applicability of the method.
作者
朱帅康
董龙雷
官威
王珺
李斌潮
ZHU Shuaikang;DONG Longlei;GUAN Wei;WANG Jun;LI Binchao(School of Aeronautics and Astronautics,Xi’an Jiaotong University,Xi'an 710000,China;Xi’an Aerospace Propulsion Institute,Xi'an 710100,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2022年第16期93-99,共7页
Journal of Vibration and Shock
