考虑温度作用不确定性的结构损伤识别  

Structural Damage Identification Considering Uncertainty of Temperature Action

作　　者：黄民水[1,2] 程劭熙 卢海林[1] HUANG Min-shui;CHENG Shao-xi;LU Hai-lin(School of Resource and Civil Engineering, Wuhan Institute of Technology, Wuhan 430075, China;Department of Civil and Environmental Engineering, University of Alberta, Edmonton T6G 2R3, Canada)

机构地区：[1]武汉工程大学资源与土木工程学院,湖北武汉430073 [2]阿尔伯塔大学土木与环境工程系

出　　处：《土木工程与管理学报》2017年第6期36-40,共5页Journal of Civil Engineering and Management

基　　金：国家留学基金委项目(201508420074);国家自然科学基金(51378404);湖北省自然科学基金(2014CFB773)

摘　　要：环境温度变化时,材料弹性模量会发生相应变化,另外,由于材料收缩或膨胀,结构轴向将缩短或伸长,如果梁端变形受到约束,可将温度变化等效为轴向荷载。材料弹性模量的变化和轴向荷载的存在将改变结构的动力刚度,进而影响结构的自振特性,如损伤识别中不能有效地考虑温度变化导致的弹性模量变化和轴向荷载,将产生误判。文中介绍了一种考虑温度作用不确定性的结构损伤识别方法,首先介绍了温度弹性理论中温度变化对弹性模量的影响和产生轴向荷载的机理。随后基于MATLAB建立了简支梁结构的有限元程序,分析了弹性模量变化和轴向荷载对结构自振特性的影响,并和欧拉梁数值解进行了对比,验证模型的有效性。最后建立了3种损伤工况,基于改进遗传算法进行了结构损伤识别,发现该方法能够有效识别不同温度变化时结构的损伤。When ambient temperature changes, the material elastic modulus accordingly varies, and structure will contract or expand for material＇ s thermal properties. If the deformation of beam end is constrained, the temperature change can be considered as axial force. The change of material elastic modulus and existence of axial force will affect the dynamic stiffness and influence the structure natural frequency. If they cannot be considered in the damage identification, erroneous judgment will happen. This paper proposes a numerical study to identify the damage location and severity considering uncertainty of temperature action. Firstly, the influence of temperature on elastic modulus and the mechanism of equivalent axial load are introduced. Secondly, the finite element analysis program of a simply supported beam is setup based on MATLAB. The influence of elastic modulus and axial force to structural dynamic properties are studied and compared with the numerical solution of Euler beam. The model is validated. In the end, four damage cases are constructed and the identification is carried out based on improved genetic algorithm, it can be found that under different temperature variations, the damage are identified accurately.

关 键 词：损伤识别 温度作用不确定性 轴向荷载 改进遗传算法 

分 类 号：TU311[建筑科学—结构工程]