【作者】 刘军；

【导师】 周凌宇；

【作者基本信息】 中南大学 ， 土木工程， 2014， 硕士

【摘要】 摘要：钢-混凝土组合桁架结构以其优越的力学性能被广泛应用于建筑桥梁结构中。外接式组合桁架结构节点具有自重轻、刚度大、整体性能优越等特点。但在外荷载作用下,节点由于局部变形,引起节点转动,这种不同于刚接和铰接的转动特性对桁架结构受力、变形都有显著影响,但是国内外对此研究较少。本文基于已有模型试验,通过有限元分析,研究外接式组合桁架节点的转动刚度,主要研究成果如下：(1)建立了外接式组合桁架节点有限元分析模型,并与已有的试验结果进行对比,验证了分析模型的正确性。(2)以节点组成各构件为独立分析对象,分析了节点在平面内弯矩作用下构件的应力分布规律,重点分析了节点板和腹杆对节点转动刚度的影响。(3)通过对节点的参数分析,认为腹杆宽厚比、弦杆与腹杆夹角、腹杆高宽比和节点板厚度对节点转动刚度有明显影响。得到了节点转动刚度的线性回归公式,并给出了公式的适用范围。(4)建立了考虑初始转动刚度影响的钢-混凝土组合桁架梁桥有限元模型。分析了初始转动刚度对次应力、内力和变形的影响。更多还原

【Abstract】 Abstract:Steel-concrete composite truss structure is widely used in building and bridge field for its superior mechanical properties. External joint has the advantages of light weight, high stiffness and excellent overall performance characteristics. The rotation of joint which caused by local deformation of joint under load is neither the same as hinge nor the rigid connections, and it also have appreciable impact on the deformation and mechanical behavior. But related researches on rotational stiffness were rarely mentioned in domestic.On the basis of existing model experimental results, this paper focuses on the finite element analysis to research the rotational stiffness of external truss joint. The main results are as follows:(1) Establishing a external steel-concrete composite truss joint model by applying finite element software to simulate the force state and deformation under horizontal loads. Contras of finite element analysis and experiment results verified the correctness of the model.(2) Further research on rotational stiffness of external steel-concrete composite truss joint. This paper analysis the stress magnitude and distribution of joint under the in-plane bending moment base on separate analysis of each component object and focus on the influences of rotational stiffness by gusset plates.(3) Parameter analysis is carried out to research joint’s rotational stiffness and it holds that the ratio of width and thickness of ventral pole, the angle between truss chords and ventral pole, the ratio of height and width of ventral pole, and the thickness of gusset plates had a significant effect on the rotational stiffness. What’s more, making use of linear regression methods to obtain rotational stiffness formula and the scope of application is given.(4) This dissertation established the finite element model of steel-concrete composite truss bridge with the consideration of initial rotational stiffness impact. Besides it also analyses the influences on secondary stress, internal forces and deformation to get the result that it’s necessary to consider the impact of rotational stiffness when calculate the internal force of ventral pole.更多还原