RESIlient buildings using STainless steel (RESIST)

使用不锈钢的弹性建筑 (RESIST)

• 批准号: EP/W019655/1
• 负责人: Leroy Gardner
• 金额: $ 63.75万
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FW019655%2F1
• 关键词: RESIlient; buildings; using; STainless; steel

Key to the survival of a building subjected to extreme loads, such as fire, blast and impact is the provision of a robust structural frame, which can accommodate the resulting high strength and ductility demands. To this end, the performance of the beam-to-column joints is paramount, since these will be subjected to high rotation capacity demands and high tying forces, as they are required to facilitate catenary action and provide an alternative load path in the case of a sudden failure of a supporting column. The fundamental hypothesis underpinning this research project is that replacing the carbon steel components in critical parts of the joints (e.g. bolts, angle cleats, plates) with an appropriate grade of stainless steel, which has greater ductility, as well as better fire behaviour, will enhance the joint strength and ductility thus maximizing the resistance to a progressive collapse during an extreme event such as an impact, blast or fire.The project consists of 4 technical work packages with a fifth one dedicated to impact and dissemination, as outlined hereafter:WP 1 focuses on the behaviour of joints under impact loading. Stainless steel plate, bolt and weld material coupons will be tested under high strain rates to determine the material response under conditions brought about by impact loading. The obtained results will be utilised to calibrate material models explicitly accounting for strain rate sensitivity as well as fracture models considering the effect of strain rate and stress triaxiality. Furthermore, lap joints and T-stubs will be tested at high strain rates and FE models will be developed and utilised in parametric studiesWP2 studies the behaviour of material and connections at and after exposure to high temperatures ranging from 20 to 1000 degrees centigrade. Isothermal and anisothermal material coupon tests will be conducted on plate, weld and bolt material, whilst for the post fire condition, both air cooling and quenching will be considered. Upon determining the effect of temperature on material response, advanced FE models will be developed to establish the performance of double web cleat, top and seat angle cleat and extended endplate joints under and post fire conditions.WP3 investigates the behaviour of individual joints under moment and shear and double sided joints under moment, shear and tension under static and dynamic loading conditions. Both physical tests and numerical models (utilising the findings of WP1) will be generated to characterise the joint response under realistic column loss scenarios. Supplementary numerical studies on geometrically identical conventional steel joints will also be conducted to compare the performance of the novel hybrid carbon/stainless steel and conventional steel joints.WP4 will utilise all previous WPs to develop and calibrate spring joint models suitable for incorporation into FE simulations of frames using beam elements. Using OpenSees, low-, medium- and high-rise 3D steel frames employing the novel hybrid joints as well as conventional ones will be analysed under a variety of extreme hazard scenaria including impact and fire using a probabilistic approach for the variability in material, geometry and loading. The obtained results will be utilised to determine the probability of failure and derive analytical fragility curves and quantify the effect of the adoption of the novel connections on the survivability of steel framed structures. Finally, WP5 will utilise all previous WPs to develop and disseminate design guidance to maximise the impact of the research. The close collaboration with leading consultants and strong links with BSI, as well as the applicants' close familiarity and involvement with Eurocode 3 will guarantee prompt dissemination of the research findings to the relevant practices, institutions and code development bodies.

承受火灾、爆炸和冲击等极端载荷的建筑物能否生存的关键是提供坚固的结构框架，以适应由此产生的高强度和延展性要求。为此，梁柱接头的性能至关重要，因为它们将承受高旋转能力要求和高系紧力，因为它们需要促进悬链线作用并在以下情况下提供替代载荷路径：支撑柱突然失效。支持该研究项目的基本假设是，用具有更大延展性和更好防火性能的适当等级的不锈钢替换接头关键部件（例如螺栓、角夹板、板材）中的碳钢部件，将增强接缝强度和延展性，从而最大限度地抵抗冲击、爆炸或火灾等极端事件期间的渐进式倒塌。该项目由 4 个技术工作包组成，其中第五个工作包专门用于冲击和传播，如下所述：WP 1 个焦点冲击载荷下关节的行为。不锈钢板、螺栓和焊接材料试件将在高应变率下进行测试，以确定冲击载荷条件下的材料响应。获得的结果将用于校准明确考虑应变率敏感性的材料模型以及考虑应变率和应力三轴性影响的断裂模型。此外，搭接接头和 T 形短管将在高应变率下进行测试，并将开发有限元模型并用于参数研究 WP2 研究材料和连接在暴露于 20 至 1000 摄氏度高温时和之后的行为。将在板材、焊缝和螺栓材料上进行等温和非等温材料试样测试，而对于火后条件，将考虑空气冷却和淬火。在确定温度对材料响应的影响后，将开发先进的有限元模型来确定双腹板夹板、顶部和座角夹板以及延伸端板接头在火灾条件下和火灾后条件下的性能。WP3 研究单个接头在力矩和静态和动态载荷条件下的力矩、剪切和拉伸下的剪切和双面接头。将生成物理测试和数值模型（利用 WP1 的研究结果）来表征实际柱损失场景下的联合响应。还将对几何形状相同的传统钢接头进行补充数值研究，以比较新型混合碳/不锈钢和传统钢接头的性能。WP4 将利用所有以前的 WP 来开发和校准适合纳入有限元模拟的弹簧接头模型使用梁单元的框架。使用 OpenSees，采用概率方法分析材料、几何形状的变化，在各种极端危险场景下（包括冲击和火灾）对采用新型混合接头和传统接头的低、中、高层 3D 钢框架进行分析和加载。获得的结果将用于确定失效概率并得出分析脆性曲线，并量化采用新型连接对钢框架结构生存能力的影响。最后，WP5 将利用之前所有的 WP 来制定和传播设计指南，以最大限度地发挥研究的影响。与领先顾问的密切合作、与 BSI 的紧密联系，以及申请人对欧洲规范 3 的密切熟悉和参与，将保证研究成果能够迅速传播到相关实践、机构和规范开发机构。