Improved consideration of dynamic loads and effects in design of exposed structures

在裸露结构的设计中改进了对动态载荷和效应的考虑

• 批准号: 121270-2013
• 负责人: McClure, Ghyslaine
• 金额: $ 1.89万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=636479
• 关键词: Improved; consideration; dynamic; loads; effects

Current structural engineering practice continues to rely extensively on static analysis methods for design. After over 30 years of extensive use of the limit states or reliability-based design method in most structural design codes worldwide, this approach has exposed its weaknesses for assessing the mechanical security and integrity of critical structures exposed to extreme environmental loads. The performance-based design approach introduced in recent years relies heavily on past methods, essentially accepting limit-states design solutions as acceptable solutions, leaving the issues of security and integrity to the interpretation of designers. Most extreme environmental loads have potentially dynamic effects on exposed structures, and consideration of failure or progressive collapse scenarios cannot generally ignore those dynamic effects when predicting structural response. As such, true performance-based design precludes reliable and relatively accurate response prediction that is rarely feasible with simplified static methods. The goal of this research program is to assess the accuracy of some simplified static load methods described in the National Building Code of Canada and other relevant Canadian structural design standards to predict the response of exposed structures to environmental load effects such as turbulent wind, atmospheric icing, and combined wind and ice effects. The types of structures to be studied are restricted to overhead transmission line supports, telecommunication towers and masts, and various exposed non-building lattice structures and cable structures (excluding bridges). The scientific approach will combine a critical review of the available experimental results (from wind-tunnel tests or monitoring) that support current simplified load calculation methods and advanced computational mechanics techniques. In particular, fluid-structure interactions will be examined, both for bare and iced flexible structures in simulated realistic turbulent wind conditions.

当前的结构工程实践继续广泛依赖于设计的静态分析方法。在全球大多数结构设计代码中，在大多数结构设计代码中广泛使用了30多年的广泛使用，这种方法暴露了其弱点，以评估暴露于极端环境负载的关键结构的机械安全性和完整性。近年来引入的基于绩效的设计方法在很大程度上取决于过去的方法，本质上接受极限态设计解决方案是可接受的解决方案，将安全性和完整性问题留在了设计师的解释中。大多数极端的环境负荷对裸露的结构具有潜在的动态影响，并且考虑到预测结构反应时，对失败或进行性崩溃的情况通常不能忽略这些动态影响。因此，真正的基于性能的设计排除了可靠且相对准确的响应预测，这些预测很少使用简化的静态方法。该研究计划的目的是评估《加拿大国家建筑法典》和其他相关的加拿大结构设计标准中描述的一些简化的静态负载方法的准确性，以预测暴露结构对环境负荷效应的响应，例如湍流风，大气冰，并结合风和冰。要研究的结构的类型仅限于架空传输线支撑，电信塔和桅杆以及各种裸露的非建造晶格结构和电缆结构（不包括桥梁）。科学方法将结合对支持当前简化的负载计算方法和高级计算力学技术的可用实验结果（来自风洞测试或监测）的关键审查。特别是，将检查流体结构的相互作用，用于模拟逼真的湍流风条件下的裸露和冰柔性结构。