高强度钢材超高层钢结构梁柱节点的抗震性能与设计方法研究

The high strength steel will be used gradually in beam-to-column connections with the higher requirement of seismic behavior for tall steel structures. The high strength steel beam-to-column connections are key parts to ensure the safety of super high-rise structures. Research on seismic behavior of the high strength steel beam-to-column connections is the emphasis and difficulty of the design for super high-rise building structures. This project is focused on the high strength steel beam-to-column connections of the super high-rise steel structures. The constitutive relationship of high-strength steel considering damage accumulation effect is established. By theoretical analysis, numerical calculation and test study, the hysteretic behavior of the high strength steel beam-to-column connections are studied systematically. Low cycle fatigue of stress amplitude, cyclic plasticity and local buckling interactive failure mechanism of the high strength steel beam-to-column connections is revealed. Seismic design method, seismic design countermeasures to improve the ductility and to prevent brittle failure of the high strength steel beam-to-column connections are put up. This project for the safe operation guarantee of super high-rise steel structures has important scientific significance.

随着超高层钢结构对整体抗震性能要求的日益提高，梁柱节点逐渐由普通强度钢材向高强度钢材发展。高强度钢材梁柱连接节点是保证超高层结构安全的关键部位，对高强度钢材梁柱节点的抗震性能研究是超高层结构设计的重点和难点。本项目以高强度钢材超高层钢结构梁柱节点为基础，建立考虑损伤累积效应的高强度钢材的本构关系；通过理论分析、数值计算和试验，系统研究高强度钢材梁柱节点的滞回性能，揭示此类节点的高应力幅低周疲劳、循环塑性、局部屈曲相关破坏机理，提出该类节点的抗震设计方法，提出改善该类节点延性和防止该类节点脆性破坏的抗震设计对策。本项目的研究为保障我国超高层钢结构的安全运营具有重要的科学意义。

提出了一个新的延性断裂模型VMX，编写了CVGM、改进SWDM、CLOU、MMC和VMX多种断裂模型的UVARM和VUMAT用户子程序，用于对Q460和焊缝金属材料在单调荷载下和超低周疲劳的延性断裂预测。用MATLAB程序校准了上述断裂模型的材料断裂参数。用Swift-Voce模型模拟了单调荷载下Q460和焊缝金属的本构模型，识别了用于循环加载下Q460和焊缝金属的Chabaoche本构模型的参数。在常用几何和设计参数范围内，提出了翼缘加强型梁柱节点、改进型RBS节点和带防屈曲构造的翼缘削弱型梁柱节点合理改进构造措施，以提高节点延性。通过数值计算和试验，系统研究翼缘加强型梁柱节点、RBS节点及改进型RBS节点、带防屈曲构造的翼缘削弱型梁柱节点的抗震性能，揭示此类节点的破坏机理，并实现了翼缘加强型梁柱节点的断裂预测。提出了这三种类型节点的抗震设计方法和改善节点延性、防止节点脆性破坏的改进措施。项目成果对完善钢框架梁柱节点的抗震设计方法和理论具有重要的科学意义。