高强钢Q460用于改善梁柱端板连接节点火灾安全性的理论与试验研究

With the development of architectural requirements, environmental protection, design techniques and numerical modelling, constructional structures have evolved significantly in practice, which calls for higher performance materials in constructions. It is economical to employ high strength steels especially in structures where the strength can be almost utilized and where the physical dimensions of structural members can be reduced. In this project, a perspective of combining high strength steel Q460 endplate with mild steel beam and column in endplate connections is proposed and investigated. The aim of this research is to reveal more understanding on behaviour and failure mechanisms of high strength steel endplate connections in fire and after fire, in order to work out the theory and method of optimizing design to improve the connection ductility. It serves for the effective application of high strength steels in civil engineering as well as enhancing the fire safety of steel structures. Full-scale tests on high strength steel endplate connections will be conducted in fire, at ambient temperature as reference and after fire. Their experimental behaviour will be compared with that of mild steel endplate connections. Further, the current provisions of GB50017 and Eurocode3 will be validated with test results of high strength steel endplate connections. Moreover, a numerical study on high strength steel endplate connections in fire and after fire will be carried out using ABAQUS and validated against the experimental results. A further parametric study based on the validated FE model will be performed to investigate the methods of fire-resistance optimizing design and post-fire evaluation of high strength steel endplate connections. The research results are expected to be used by structural engineers as the basis to conduct safe fire-resistance design and accurate post-fire evaluation of steel structures with high strength steel members, in order to keep pace with the practical application of high strength steels. They can also be considered for the revision of current leading design standards.

作为一种新兴环保节约型材料，高强钢在土木工程中的应用符合可持续发展战略及节能环保型社会的建设。本项目拟研发国产高强钢与普通钢在梁柱端板连接中结合使用的优化设计理论与方法，期望充分发挥高强钢与普通钢各自的优点与结合应用的经济性，改善节点的火灾延性，进而提高结构整体的火灾安全性，为高强钢在土木工程领域的合理应用提供理论支撑。明确高强钢Q460端板连接节点在火灾下及火灾后的工作性能，验证我国与欧洲钢结构设计规范对其适用性，提出抗火优化设计方法，是该项目的关键也是当前工程领域亟需解决的问题。本项目拟针对高强钢Q460端板连接节点在火灾下及火灾后的失效演化机理、破坏模式、承载力、转动性能与优化设计控制参数等，展开理论与试验研究，探索该节点的抗火优化设计方法，提出其火灾后性能评定方法与理论。其成果对推广高强钢在土木工程领域的合理应用、解决目前工程实际超前理论方法滞后的问题，具有重要的理论与社会意义。

作为一种新兴环保节约型材料，高强钢在土木工程中的应用符合可持续发展战略及节能环保型社会的建设。本项目通过与全高强钢端板连接节点的对比，研发国产高强钢与普通钢在梁柱端板连接中结合使用的优化设计理论与方法，期望充分发挥高强钢与普通钢各自的优点与结合应用的经济性，改善节点的火灾延性，进而提高结构整体的火灾安全性，为国产高强钢在土木工程领域的合理应用提供理论支撑。明确高强钢端板连接节点在火灾下及火灾后的工作性能，验证欧洲钢结构设计规范对其适用性，提出抗火优化设计方法，是该项目的关键也是当前工程领域亟需解决的问题。本项目针对国产高强钢端板连接节点在火灾下及火灾后的失效演化机理、破坏模式、承载力、转动性能与优化设计控制参数等，展开理论与试验研究，探索该节点的抗火优化设计方法，提出适用于高强钢的节点力学性能评定理论。其成果对推广高强钢在土木工程领域的合理应用、解决目前工程实际超前理论方法滞后的问题，具有重要的理论与社会意义。