摘要
提出了根据动力特性试验识别结构的模态参数,运用优化算法修改动力有限元模型,进而评价复杂承载钢结构综合性能的方法。针对复杂承载钢结构的结构特点和激振形式,推导了模态参数识别公式;介绍了有限元模型动力修正的一阶搜索优化算法。利用近似平稳随机激励,对井架钢结构进行了现场模态试验,识别出前三阶固有频率和前二阶振型,分析了该结构的实际运行状况。仅依据前二阶固有频率,应用一阶搜索的优化算法,对动力有限元模型进行了修正,重分析表明:该修正模型实现了前三阶固有频率和应力特征的精确反演,能够用于进一步的静、动力分析和综合性能评价。
To evaluate the over-all properties of complex load carrying steel structures, a novel method is proposed based on modal parameters identified from dynamic test and finite element updating model with optimization. According to the design feature and the shock excitation mode of complex load carrying steel structures, the formulas are deduced for identifying modal parameters, and the first order optimization method is described. The modal test of derrick steel structures is carried out using approximate stationary random motivation. The first three natural frequencies and first two mode shapes are identified, and the operating characteristic of the structure is obtained.Only the first two natural frequencies are used for updating the finite element model with the first order optimization. The updating results show that the first three natural frequencies and stresses are acquired exactly. Therefore, the updating finite element model can be employed for the analysis of static/dynamic characteristics and total properties of loaded steel structures.
出处
《应用力学学报》
CAS
CSCD
北大核心
2008年第4期678-682,739-740,共5页
Chinese Journal of Applied Mechanics
基金
中国石油天然气集团公司科学研究与技术开发项目(03B209000)
关键词
承载钢结构
模态参数
综合性能
有限元模型
优化
评价
load carrying steel structures,modal parameters ,Over-all properties, finite element model optimization, evaluation.
