高层建筑风致疲劳分析中的钢材强度退化模型  

Steel Strength Degradation Model for Wind-induced Fatigue Analysis of High-rise Buildings

作　　者：郑晓伟 吕恒林 李宏男 张营营 ZHENG Xiaowei;LYU Henglin;LI Hongnan;ZHANG Yingying(School of Mechanics and Civil Engineering,China University of Mining and Technology,Xuzhou 221116,China;Jiangsu Collaborative Innovation Center for Building Energy Saving and Construction Technology,Xuzhou,221116,China;Faculty of Infrastructure Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]中国矿业大学力学与土木工程学院,江苏徐州221116 [2]江苏建筑节能与建造技术工程技术中心,江苏徐州221116 [3]大连理工大学建设工程学部,辽宁大连116024

出　　处：《防灾减灾工程学报》2022年第2期276-282,共7页Journal of Disaster Prevention and Mitigation Engineering

基　　金：中央高校基本科研业务费专项资金(2021-11044);徐州市住房和城乡建设局攻关项目(2019-10612)资助。

摘　　要：全寿命周期内风荷载长期作用下,钢结构中的钢材和节点将出现不同程度的累积损伤。风致疲劳损伤后结构的抗震能力必然发生相应变化,而疲劳累积损伤条件下的材料和节点剩余力学性能模型,是准确开展损伤后结构抗震性能评估的关键。鉴于此,通过贝叶斯理论,建立基于物理机制的钢材强度退化模型分析方法。首先,收集高周疲劳预损伤钢材强度退化的试验数据,并选取常用的强度退化模型,通过贝叶斯更新准则确定了退化模型参数的后验估计值。其次,基于钢材强度退化模型,给出了确定风致疲劳劣化焊接梁柱节点弯矩和转角骨架曲线的分析方法。结果表明:(1)疲劳累积损伤条件下的传统钢材强度退化模型离散性大,且缺少必要的数学和物理依据,而基于贝叶斯理论的强度退化模型可有效弥补这一缺陷;(2)相同试验数据,不同强度退化模型得到的结果差异性较大,且不存在普遍适用的最优模型。通过贝叶斯理论建立的钢材强度退化模型,可有效考虑材料型号、试件尺寸、疲劳荷载模式和加载机制等多种因素对试验结果的影响,且可借此反映风致累积损伤对结构性能退化的影响,有助于提高风致疲劳损伤后高层钢结构建筑地震风险评估结果的可靠性。In the whole lifetime of steel structures subject to long-term wind loads,there will be fatigue damage accumulation in the steel material and beam-to-column connections. Seismic performance of the structures will certainly change because of the wind-induced fatigue. It is essential to determine the residual mechanical properties of the steel materials and connections under the action of fatigue cumulative damage when assessing the seismic performance of the deteriorated structures. In this regard,a Bayesian-based method is proposed to establish the physics-based strength degradation model of steel. Firstly,collect the static mechanical experimental data of pre-fatigued steel and choose the widely used strength degradation models,then the Bayes theory is used to develop posterior probability distribution of the unknown model parameters. Secondly,according to the strength degradation model of steel,an analytical method is presented to develop the moment-rotation model for the fatigued welded connections. It can be concluded that:(1)Traditional strength degradation model considering the fatigue cumulative damage will produce large scatter,and lacks necessary mathematical and physical background,which limits their applications,on the contrary,the degradation model obtained by the Bayesian-based method can effectively reduce the model error.(2)For the same test data,there is significant difference in different degradation models and there is no universally applicable optimal strength degradation model. The effects of steel type,experimental specimen size,fatigue load mode and loading mechanism can be well considered in the proposed physics-based strength degradation model. Furthermore,this presented degradation model can be used to reflect the impacts of the wind-induced fatigue cumulative damage on the structural behaviors’ deterioration,which is beneficial to improve the reliability of seismic risk assessment on the deteriorated high-rise steel structure buildings suffered the wind-induced fatigue cumulative damag

关 键 词：强度退化模型 风致疲劳 贝叶斯理论 焊接节点 高层钢结构 

分 类 号：TU312[建筑科学—结构工程]