基础激励下裂纹梁结构疲劳寿命预测模型  

Fatigue Life Predication Model for a Cracked Beam Structure Under Base Excitations

作　　者：龙慧[1] 黄长征[1] 刘义伦[2] 李松柏[2] LONG Hui;HUANG Chang-zheng;LIU Yi-lun;LI Song-bai(School of Intelligent Engineering,Shaoguan University,Guangdong Shaoguan 512005,China;School of Mechanical Engineering,Central South University,Hu’nan Changsha 410083,China)

机构地区：[1]韶关学院智能工程学院,广东韶关512005 [2]中南大学机电工程学院,湖南长沙410083

出　　处：《机械设计与制造》2024年第9期77-84,共8页Machinery Design & Manufacture

基　　金：国家自然科学基金面上项目(51575358);广东省教育厅重点学科建设项目(2022ZDJS050)。

摘　　要：为了发展基于模型的裂纹梁结构疲劳寿命预测方法,提出了一种新的三维裂纹梁单元刚度矩阵。基于该刚度矩阵,建立基础激励下裂纹梁结构的三维有限元模型。推导三维裂纹梁单元的应力强度因子,建立三维裂纹梁单元的疲劳裂纹扩展模型。采用振动响应与裂纹扩展增量交互计算方法,计算循环载荷作用下裂纹梁结构的疲劳寿命。研究结果表明:裂纹梁结构寿命预测模型较好地体现了疲劳裂纹扩展寿命与基础激励参数、结构参数和裂纹参数之间的内在关系,反映了基础激励对裂纹梁结构疲劳寿命的影响。最后通过实验对模型进行了验证。For the purpose of developing a reliable model-based approach,a new stiffness matrix of a three-dimensional(3D)fi⁃nite element is proposed for modelling a cracked beam structure.Using the obtained stiffness matrix,the 3D finite element model of the cracked beam structure was established.The equation of stress intensity factor for the 3D beam element with a crack was formed,and the fatigue crack growth model for the 3D beam element with a crack was established.The dynamic response and crack growth increment was calculated interactively,and lasts from the initial crack length to final crack length cycle by cycle.The study shows that fatigue life prediction model discovers the internal relation between the fatigue crack growth and base excita⁃tion parameters,structural parameters and crack parameters,and that the effect of base excitation on fatigue crack growth of the cracked beam structure was determined and discussed.Finally,an experiment was conducted to validate the analytical results.

关 键 词：基础激励 裂纹梁结构 有限单元法 疲劳寿命 动力学模型 裂纹扩展 

分 类 号：TH16[机械工程—机械制造及自动化] TH113.1