基于不同结构损伤模型的RC框架地震易损性研究

Seismic Vulnerability Analysis of RC Frame Structures through Different Structural Damage Models

针对目前RC框架结构地震易损性分析中整体损伤模型研究的薄弱性以及广泛采用的层间位移角方法不能准确反应结构在地震作用下损伤机理的现状,本文基于现有损伤模型的对比分析,提出了一种较准确反映地震破坏机理同时便于应用的最大变形和滞回耗能非线性组合的双参数损伤模型。以8层RC框架结构为例,进行50条地震波作用下的结构增量动力分析,分别绘制了变形和能量2种单参数模型以及牛荻涛模型和本文模型两种双参数模型的结构损伤曲线与易损性曲线,并进行了模型的对比分析和检验评估。分析结果表明:仅以层间位移角作为结构整体损伤指标会高估结构的抗倒塌性能,仅以能量作为结构整体损伤指标会低估结构损伤的超越概率。本文模型能较好地平衡最大变形和累积损伤对结构损伤的影响程度。

The work proposes a nonlinear combination,two-parameter damage model of maximum deformation and hysteretic energy dissipation.Comparing the performance of the proposed model with that of existing damage models reveals that the proposed model can accurately reflect the earthquake damage mechanism.For comparison,the structural damage curves and seismic fragility curves of two single-parameter models(deformation and energy)and two two-parameter models(Niuditao model and the proposed model)are drawn in accordance with the incremental dynamic analysis results of an eight-story RC frame structure under the input of 50 seismic waves.Results show that structural collapse performance will be overestimated when the interstory drift angle is used as the sole structural damage index,whereas the exceedance probability of structural damage will be underrated if energy dissipation is used as the sole structural damage index.The proposed model can well balance the influence of maximum deformation and cumulative damage on structural damage.