基于杆系离散元的半刚性连接数值计算方法研究  

Study on numerical calculation method of semi-rigid connections based on member discrete element theory

作　　者：许强[1,2] 叶继红 XU Qiang;YE Jihong(Jiangsu Key Laboratory Environmental Impact and Structural Safety in Engineering,China University of Mining and Technology,Xuzhou 221116,China;Xuzhou Key Laboratory for Fire Safety of Engineering Structures,China University of Mining and Technology,Xuzhou 221116,China)

机构地区：[1]中国矿业大学江苏省土木工程环境灾变与结构可靠性重点实验室,江苏徐州221116 [2]中国矿业大学徐州市工程结构火安全重点实验室,江苏徐州221116

出　　处：《建筑结构学报》2022年第12期311-321,共11页Journal of Building Structures

基　　金：国家自然科学基金重点项目(51538002);国家重点研发计划(2017YFC1500703)。

摘　　要：在钢结构中梁柱的连接多以半刚性连接为主,可靠的半刚性连接数值计算方法对于钢结构设计和分析具有重要的工程实用价值。为此,基于杆系离散元(MDEM)理论,提出了离散元分析模型,通过在杆件末端设置虚拟的多自由度弹簧单元以模拟钢结构的半刚性连接行为。与传统有限元法不同,在离散元法中,虚设的零长度弹簧单元无长度但有质量,并且作为基本分析单元,直接参与计算过程,其响应即为半刚性连接行为。算例分析表明:在半刚性连接离散元模型中,通过改变零长度弹簧刚度可实现对刚接、铰接和半刚性连接的模拟;半刚性连接会显著降低结构整体刚度,静力荷载作用下若将其简化为刚性,会高估结构的承载能力;当施加的动荷载频率与结构基本频率相近时,与刚性和线性连接相比,非线性连接时材料的塑性变形会引起能量耗散,从而避免产生共振。In actual steel structures, beam-column nodes are mostly semi-rigid connections. The reliable numerical calculation method of semi-rigid connections has important engineering practical value for the design and analysis of steel structures. Based on the member discrete element method(MDEM), a discrete element analysis model is proposed to simulate the semi-rigid connection behavior of steel structures by setting a virtual multi-degree-of-freedom spring element at the end of the member. Different from that in the traditional finite element method, the dummy zero-length spring element in the MDEM has no length but has a mass, and it is regarded as the basic analysis element directly participating in the calculation process. The response of the spring element represents the behavior of semi-rigid connections and has explicit physical meaning. The analysis results of the examples show that in the member discrete element model of semi-rigid connections, the simulation of rigid connections, hinged connections and semi-rigid connections can be realized by changing the stiffness of the zero-length spring. Semi-rigid connections would significantly reduce the overall stiffness of the structure, and if they are simplified to be rigid under static loads, the bearing capacity of the structure would be overestimated. When the frequency of the applied dynamic load is close to the fundamental frequency of the structure, compared to rigid and linear semi-rigid connections, hysteresis damping of nonlinear semi-rigid connections due to plastic deformation can cause energy dissipation, thus avoiding the occurrence of resonance.

关 键 词：钢框架 半刚性连接 杆系离散元 屈曲 动力响应 

分 类 号：TU391[建筑科学—结构工程]