摘要
利用有限元模型修正技术综合利用理论建模和实验建模的优点,可以得到更加符合结构实际的基准模型,为结构动力分析、损伤诊断及健康监测提供更可靠的依据。基于一12层钢筋混凝土框架模型振动台试验测点加速度记录,采用特征系统实现算法对该模型结构进行模态参数识别,识别结果与有限元分析结果之间存在明显的差异。采用基于灵敏度分析的参数型有限元模型修正技术,选择识别精度较高的实测模态频率为修正基准,以构件的弹性模量和密度为修正参数,对该框架的初始有限元模型进行了修正,得到基准有限元模型。进一步以基准有限元模型为标准,以构件弹性模量的降低模拟结构的损伤,对两种假设工况下的损伤结构进行修正,得到构件弹性模量的变化值并与假设的降低值对比,验证了有限元模型修正技术在结构损伤识别中应用的可行性。
Finite element model updating technique takes advantage of both analytical modelling and experimental modelling.Thus more reliable baseline model can be obtained for further dynamic analysis,damage diagnosis and health monitoring.Modal parameters of a 12-storey reinforced concrete frame are identified by eigensystem realization algorithm through processing the acceleration records of shaking table test at gauging points.Comparison with the results from initial finite element analysis shows that there is distinct discrepancy between identified and analyzed modal parameters.Then,the identified frequencies which are more accurate than mode shapes are taken as updating benchmark and elastic moduli and densities of components are selected as updating parameters.The initial finite element model is updated based on sensitivity analysis and the baseline model is founded.Furthermore,the elastic moduli reduction of some components is taken to simulate the damage state and two cases with different damaged components are investigated on the basis of the baseline model.Component elastic moduli are obtained from model updating and their reduction values are compared with the supposed ones.The updated results of these simulated cases verify the feasibility of finite element model updating technique for damage identification.
出处
《地震工程与工程振动》
CSCD
北大核心
2010年第5期87-92,共6页
Earthquake Engineering and Engineering Dynamics
基金
甘肃省科技攻关项目(2GS057-A52-008)
关键词
有限元法
特征系统实现算法
模型修正
灵敏度分析
损伤识别
振动台试验
finite element method
eigensystem realization algorithm
model updating
sensitivity analysis
damage identification
shaking table test
