A probability-based methodology for the analysis of fluctuating wind loads on cable-supported bridges

摘要：CMS 0600575考虑到风场、湍流波动和压力分布的固有复杂性，与风荷载相关的自然灾害情景的预测和模拟尤其困难。因此，无论是全尺寸试验还是风洞试验，对于动载的推导都是至关重要的。尽管研究界努力开发改进的技术，但预测有时可能与等效力或响应特性的记录值不同。这些差异与这门学科的实验性质有关。这一观察结果要求在所有风能工程应用中通过基于概率的方法更全面地处理不确定性。大跨度缆索支撑桥梁是美国基础设施系统的骨干，位于主要公路网系统沿线，连接全国各地的重要节点。该研究项目将提出和开发一种创新的方法来推导大跨度桥梁抖振问题的解决方案，这将涉及通过集中在气动输入和选定的结构参数中的统计描述符来直接表示不确定性来源。将从首席调查员可获得的数据和信息中进行比较。风洞实验将被用来确认气动和气动弹性力项的不确定定义的相关性。值得强调的是，虽然颤振引起的坍塌可以从概率的角度重新解释为可靠性问题(即，需要在统计上避免的情况)，但抖振不能完全与唯一的安全指标相关联，而是与故障和可服务性条件两者相关

Abstract: CMS 0600575 The prediction and simulation of natural hazard scenarios associated with wind loading are particularly difficult in consideration of the inherent complexity of the wind field, turbulence fluctuations and pressure distributions. Therefore, experimentation, either full-scale or in wind tunnel, is vital for the derivation of the dynamic loading. Despite the efforts of the research community towards the development of refined techniques, predictions can, on occasion, differ from the recorded values of equivalent force or response characteristics. These discrepancies are associated with the experimental nature of this discipline. This observation calls for a more comprehensive treatment of uncertainty through probability-based methods in all wind engineering applications. Long-span cable-supported bridges are the backbone of the infrastructural system in the United States, located along the primary highway network system and connecting vital joints across the Nation. The research project will propose and develop an innovative approach for deriving the solution to the buffeting problem on long-span bridges, which will involve the direct representation of the sources of uncertainty through statistical descriptors, concentrated in both the aerodynamic input and selected structural parameters. Comparisons will be pursued from data and information available to the Principal Investigator. Wind-tunnel experiments will be used to confirm the relevance of the uncertain definition of aerodynamic and aeroelastic force terms. It is worth emphasizing that, whereas the collapse due to flutter can be re-interpreted from a probabilistic point of view as a reliability problem (i.e., a condition that needs to be avoided statistically), buffeting cannot be exclusively associated with a unique safety index but is related to both failure and serviceability conditions