铝合金结构环槽铆钉连接受力机理及其梁柱节点承载性能研究

Recently, the application of aluminum alloy structures in China is becoming more and more general, because of its light weight, high strength, good corrosion resistance, beautiful appearance and easy extrusion process, the needs of using aluminum alloy structures in frame structures increase. In order to achieve this goal, the loading behavior of the aluminum alloy beam-to-column joints should be clarified, however, there is nearly no research in this field. And the strength of welded aluminum alloy is low, while it is complex to use ordinary bolts in such kinds of structures, therefore, it is essential to apply new connection method to fabricate the joints. Focusing on these research points, the current application use the combined methods including: theory analysis, experiment analysis and numerical analysis to carry out the research on the following three aspects: component, connection and joints. Researches will be conducted on the mechanical behavior of swage-locking pin and its preload and tension-shear loading behavior will be clarified. The experimental research on the bearing strength of swage-locking pin connected aluminum alloy plates will be performed and the corresponding design method will be proposed. The tests will also be conducted on the aluminum alloy T-stub to investigate its tensile behavior and then propose the design method. Finally, the experiments and analysis will be conducted on the swage-locking pin connected aluminum alloy beam-to-column joints under static and dynamic loads and then give the suggestion of design. The research of current application has significant meanings to complete the design codes of Chinese aluminum alloy structures and guide the practical engineering and it’s important to the security and economy of aluminum alloy structures.

近年来，铝合金结构在我国应用越来越广泛，由于其轻质高强、耐腐蚀、外形美观、易于挤压成型等优点，将铝合金结构应用在框架结构和厂房等排架结构中的需求也不断增加。要在框架结构中使用铝合金，则需要解决其梁柱节点承载性能的问题，而这一问题在国内外尚无研究。而建筑用普通铝合金焊接强度低，而螺栓连接构造和施工技术复杂，需要新型连接方法来组装节点。针对这些研究目前的不足，本申请项目采用理论分析、试验研究和数值模拟相结合的方法，从元件、连接和节点三个层面展开逐步深入的研究。开展对环槽铆钉力学性能的研究，得到其预紧力以及拉剪受力性能；进行环槽铆钉连接的铝合金板件孔壁承压强度试验并提出设计方法；进行环槽铆钉连接的铝合金T型件的受拉性能试验并提出设计方法；最后对环槽铆钉连接的铝合金梁柱节点进行静力下和循环荷载下加载并提出设计方法。本项目的研究对于完善铝合金结构设计规范、提高铝合金结构的安全性、经济性具有重要意义。

建筑结构常用的铝合金材料可焊性差，所以紧固件连接自然成为铝合金结构的最佳选择。本项目结合力学性能优异的新型紧固件环槽铆钉，提出了可有效连接铝合金结构构件的节点形式，并紧密围绕铝合金结构环槽铆钉连接与梁柱节点开展了系统性的深入研究：.（1）通过试验研究获取了环槽铆钉的预紧力数值及其损失情况，并开展了44个铆钉在不同受力状态下承载能力测试。建立了环槽铆钉精细化有限元模型和计算效率更高的简化模型，并从数值结果中提取铆钉拉脱过程的特征信息从而对拉脱机理进行揭示，进而推导了拉脱力公式。提出了环槽铆钉承载力设计方法并通过试验与数值结果验证了其准确性。.（2）开展了23个受剪连接拉伸试验，其中包括3种环槽铆钉布置形式，并考虑了铝合金牌号，铆钉端距、边距和中距对试件受力性能的影响。试验中还测试了4种牌号铝合金板件的材料力学性能和抗滑移系数。以试验为基础，验证了所建立的有限元模型并开发自动计算程序、开展了930个参数分析。在厘清受力机理后，提出了受剪连接设计方法。.（3）开展了30个环槽铆钉T型连接受拉试验，并基于试验进行了系统性的有限元分析与受力机理研究。.（4）提出了两种环槽铆钉连接的铝合金梁柱节点形式并开展了10个足尺节点的单调加载试验和4个循环加载试验，对节点的承载性能及破坏模式、延性与耗能能力深入分析。建立并验证了相应的有限元模型。.（5）以上述研究为基础并结合组件法，提出了适用于此类节点的设计方法，包括：初始刚度、承载能力、弯矩-转角全曲线、构造建议及滞回模型。