Response of Steel Beam-to-Column Connections to Dynamic Loading

钢梁柱连接对动载的响应

• 批准号: EP/F002599/1
• 负责人: Simon Tait
• 金额: $ 15.01万
• 依托单位: University of Bradford
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FF002599%2F1
• 关键词: Response; Steel; Beam; Column; Connections

The after-effects of the events of 11 September 2001 are still reverberating around the world. The collapse of buildings at the World Trade Centre (WTC) has thrown the field of structural engineering into the spotlight and professionals and the public alike have a heightened awareness of the dangers posed by the collapse of buildings. The post-WTC deliberations have highlighted and brought into sharp focus a previously limited debate on the shortcomings in our knowledge of the response of framed buildings to accidental or malicious damage. Even before the September 11 attacks, an American government working party stated that Progressive structural collapse is a primary, if not the leading, cause of injury and death in building failures, regardless of the source of loading...For this reason, predicting and designing to prevent progressive collapse of a building under a specified attack scenario is (and should be) a primary objective... The same report noted that ...guidance on building collapse and building code requirements would be valuable. The phenomenon of progressive collapse is not well understood, despite the widespread recognition that most building failures include building collapse. Although building codes admonish designers to ensure that collapse does not occur, they do not provide guidance on how this can or should be accomplished. Among their recommendations is The nature and mechanism of progressive collapse is a subject that merits further study by the academic community. This topic, which has not been addressed at a meaningful level for almost a quarter of a century, could have benefits in mitigating risks from many hazards. The situation in the United Kingdom is similar. A pre-September 11 report acknowledged that, whilst the requirement for structures to be robust against accidental damage is not disputed, there is presently no established basis for determining how much redundancy is required in order to provide an acceptable level of safety in the event of damage, or to estimate how the forces in a damaged structure are redistributed. The same report pointed out that, inherent robustness of buildings may have been compromised by advances in structural analysis and design, which have enabled the designer to model a structure more accurately. This, it argued, has reduced the usual over-design of structural frames in the pursuit of economy of construction, and may have resulted in buildings with reduced robustness. Although current UK design guidelines emphasise the importance of catenary action in providing robustness against damage in framed buildings, and the consequent requirement for tensile capacity of members and connections, in practice, it is likely that both moment resistance (in Virendeel bridging action) and shear resistance (to debris loading) of connections will be equally important. Recent authoritative publications in both the UK and USA have highlighted the current lack of knowledge of the dynamic response of bolted steel connections and there is a pressing need for authoritative data on both the response of different types of framed structures to damage (a topic already under investigation by the proposers and the subject of an earlier research proposal), and the dynamic behaviour of steel connections.The overall aim of this project is to conduct an experimental study of the response of steel connections to dynamic loading and compare the results with existing design recommendations. A range of connections typical of those used in UK construction will be examined, including web cleats, fin plates, partial depth- , flush- and extended endplates.

2001 年 9 月 11 日事件的后果仍在世界各地产生影响。世界贸易中心 (WTC) 建筑物的倒塌使结构工程领域成为人们关注的焦点，专业人士和公众都提高了对建筑物倒塌带来的危险的认识。世贸中心后的审议突出并引起了先前有限的辩论的关注，该辩论是关于我们对框架建筑对意外或恶意损坏的反应的认识上的缺陷。甚至在 9 月 11 日袭击之前，一个美国政府工作组就表示，无论荷载来源如何，渐进式结构倒塌即使不是导致建筑物倒塌的主要原因，也是造成伤害和死亡的主要原因……因此，预测和设计以防止建筑物在特定攻击情况下渐进式倒塌是（并且应该是）首要目标……同一份报告指出……有关建筑物倒塌和建筑规范要求的指导将很有价值。尽管人们普遍认识到大多数建筑故障都包括建筑物倒塌，但渐进式倒塌现象尚不清楚。尽管建筑规范告诫设计师确保不会发生倒塌，但它们没有提供有关如何或应该如何实现这一目标的指导。他们的建议之一是“渐进崩溃的性质和机制”是一个值得学术界进一步研究的课题。这个话题近四分之一个世纪以来都没有得到有意义的解决，但它可能有助于减轻许多危害的风险。英国的情况也类似。 9 月 11 日之前的一份报告承认，虽然对结构坚固耐用以防止意外损坏的要求没有争议，但目前还没有既定的基础来确定需要多少冗余才能在发生损坏时提供可接受的安全水平，或估计损坏结构中的力如何重新分布。同一份报告指出，结构分析和设计的进步可能会损害建筑物固有的坚固性，而结构分析和设计的进步使设计师能够更准确地对结构进行建模。它认为，这减少了为了追求建筑经济性而通常对结构框架的过度设计，并可能导致建筑物的坚固性降低。尽管英国现行的设计指南强调了悬链线作用在框架建筑中提供坚固性以防止损坏的重要性，以及随之而来的对构件和连接件抗拉能力的要求，但在实践中，连接件的力矩阻力（在 Virendeel 桥接作用中）和剪切阻力（对碎片荷载）可能同样重要。英国和美国最近的权威出版物强调了目前对螺栓钢连接动态响应知识的缺乏，迫切需要关于不同类型框架结构对损坏的响应（提案者已经在研究的主题和早期研究提案的主题）和钢连接的动态行为的权威数据。该项目的总体目标是对钢连接对动态加载和动态响应的响应进行实验研究。 将结果与现有设计建议进行比较。将检查英国建筑中使用的一系列典型连接，包括腹板夹板、翅片板、部分深度、齐平和延伸端板。