As inelastic design for wind is embraced by the engineering community, there is an increasing demand for computational tools that enable the investigation of the nonlinear behavior of wind-excited structures and subsequent development of performance criteria. To address this need, a probabilistic collapse assessment framework for steel structures is proposed in this paper. The framework is based on the integration of a high-fidelity fiber-based nonlinear structural modeling environment with a wind-tunnel-informed stochastic wind load model to perform nonlinear time history analysis. General uncertainty is propagated using a stratified sampling scheme enabling the efficient estimation of reliabilities associated with rare events. The adopted models for simulating high-fidelity nonlinear structural behavior were found, in general, to be adequate for capturing phenomena, including progressive yielding, buckling, and low-cycle fatigue, that are essential for wind induced collapse analysis. In particular, the adopted fatigue model was found to be capable of predicting damage and potential fiber/section fracture associated with non-fully reversing stress-strain cycles that are characteristic of wind loading. Through illustration on a 45-story archetype steel building, critical discussions on the types of observed collapse mechanisms, the difference between alongwind and acrosswind nonlinear behavior, reliabilities associated with first yield, and collapse are presented. A probabilistic description of the residual and peak story drifts is also provided through development of fragility functions.
翻译:由于工程界接受风的弹性设计,对计算工具的需求日益增加,这些工具有助于调查风刺激结构的非线性行为,并随后制定性能标准。为解决这一需要,本文件提出了钢结构的概率崩溃评估框架。框架的基础是将高纤维纤维纤维型非线性结构模型环境与风洞知情的随机风负载模型相结合,以进行非线性时间历史分析。一般不确定性的传播采用分层抽样计划,以便能够有效估计与稀有事件有关的再生性。为模拟高纤维性非线性非线性结构行为而采用的模式,一般而言足以应对钢结构的概率崩溃评估框架。这一框架的基础是将高纤维性纤维性纤维型非线性结构模型与风引发性崩溃分析所必不可少的一个高纤维性纤维型结构模型结合起来。所采用的疲劳模型被认为能够预测与非线性逆转性压力紧张性循环相关的损害和潜在纤维/部门性骨折,而这种循环是风力装载特征的特征。所特有的模拟高纤维性非线性结构结构结构结构的模拟模型和低周期性结构结构结构图解是第45型结构型结构型结构结构结构结构结构结构结构的缩。通过观察式结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构的缩缩图解,通过观察,在所观察到的图式结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构结构上进行初步分析中进行初步分析中进行中进行演示。