轻型钢结构厂房动力特性分析及损伤识别研究

针对钢结构厂房的结构设计和损伤检测问题,本文以某汽配企业三跨钢结构双坡单层厂房为研究对象,基于模态分析理论,通过有限元软件ABAQUS建立钢结构厂房的整体模型和单榀模型,并将整体模型与单榀模型动力特性的前10阶模态进行比较。将单榀模型作为损伤识别研究对象,提取了该单榀厂房结构在6种工况下各单元的模态参数,利用Matlab计算每个单元的模态应变能变化率。结果表明,厂房整体空间框架前5阶模态振型为第二跨和第三跨发生水平摆动和扭摆,从第六阶开始模态振型变为整体扭摆。整体模型结构频率分布集中在1Hz和2Hz之间,且基本频率比平面框架高,说明其整体性比较强。以单元模态应变能变化率作为钢结构厂房的损伤识别量,可对钢结构厂房的单处不同损伤位置和程度进行损伤识别,可以作为钢结构厂房进一步研究和定期检测的方法。

Aiming at the structural design and damage detection of the steel structure workshop,this paper takes the double-slope single-storey workshop with three-span steel structure of an auto components enterprise as the research object.Based on the modal analysis theory,the overall model and single beam model of the steel structure workshop are established through the finite element software ABAQUS,and the first 10 modes of the dynamic characteristics of the overall model and single frame model are compared.Taking the single beam model as the research object of damage identification,the modal parameters of each element of the single beam workshop structure under 6 working conditions are extracted,and the modal strain energy change rate of each element is calculated by Matlab.The results show that the first five modal modes of the overall space frame of the workshop are horizontal swing and torsional pendulum in the second and third spans,and the modal mode changes to the overall torsional pendulum from the sixth order.The frequency distribution of the overall model structure is concentrated between 1Hz and 2Hz,and the fundamental frequency is higher than that of the plane frame,indicating that its integrity is relatively strong.Taking the unit modal strain energy change rate as the damage identification quantity of the steel structure workshop,the damage identification can be carried out for different damage locations and degrees of the steel structure workshop,which can be used as a method for further research and regular inspection of the steel structure workshop.