随机荷载作用下参数不确定结构的疲劳损伤估计  

Fatigue damage evaluation of structure with uncertain parameters under random load

作　　者：朱颖 双妙 ZHU Ying;SHUANG Miao(Railway Engineering Research Institute,China Academy of Railway Sciences,Beijing 100081,China;State Key Laboratory for Track Technology of High-speed Railway,Beijing 100081,China;State Nuclear Electric Power Planning,Design&Research Institute Co.Ltd.,Beijing 100095,China)

机构地区：[1]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [2]高速铁路轨道技术国家重点实验室,北京100081 [3]国核电力规划设计研究院有限公司,北京100095

出　　处：《振动工程学报》2020年第1期88-98,共11页Journal of Vibration Engineering

基　　金：中国铁路总公司科技研究开发计划重大课题(2017G006-A);国家自然科学基金资助项目(51378061)

摘　　要：基于改进区间分析和频域疲劳计算方法,对参数不确定结构在平稳高斯荷载作用下的疲劳损伤进行研究,提出完全混合和简化计算两种方法。采用区间变量模型定义结构的不确定参数,功率谱密度描述外荷载的随机性;利用有理级数显式表示结构区间频响函数及在平稳高斯荷载作用下不确定结构的应力响应区间。通过数值方法验证疲劳损伤期望率关于不确定参数的单调性后,将应力响应中不确定参数的界限完全组合提出完全混合方法,准确估计参数不确定结构的疲劳损伤期望率区间;简化计算方法则将不确定参数的界限适当组合,由显式表达式近似计算结构的疲劳损伤期望率区间。算例表明,两种方法均具有较高计算精度,且大幅减少计算量。Based on improved interval analysis and spectral fatigue estimate methods,two new approaches,full combination method and simplified method,are presented to evaluate fatigue damage of structure with uncertain parameters under stationary Gaussian load,in which interval variables are introduced to describe uncertain parameters of structural systems.In proposed methods,uncertain parameters of structure are defined by interval parameter models,and randomness of external loads is described by power spectral density.Interval frequency response functions of structure and dynamic response intervals of uncertain structure under stationary Gaussian load are explicitly expressed by the Rational Series Expansions.The proposed full combination method wholly combines the bounds of uncertain parameters in the fatigue estimation stage,which can accurately estimate intervals of expected fatigue damage rate of structure with uncertain parameters.The simplified method properly combines the bounds of uncertain parameters,which approximately calculates intervals of expected fatigue damage rate through explicit expression.Finally,numerical examples are used to illustrate the accuracy and applicability of the proposed methods.It is shown that both methods have high calculation accuracy and greatly reduce the amount of calculation.

关 键 词：随机振动 疲劳损伤期望率 改进区间分析 结构不确定 单调性 

分 类 号：O324[理学—一般力学与力学基础] O346.2[理学—力学]