【作者】 胥彦斌；

【导师】 郭成喜；

【作者基本信息】 西安建筑科技大学 ， 结构工程， 2008， 硕士

【摘要】 冷弯型钢桁架中腹杆通常假定两端为铰接连接,然而对其节点的真实特性目前研究还不够充分,我国的设计规范没有考虑节点刚度。本文引用了国外的试验数据并对其进行了数值分析,目的在于研究冷弯型钢桁架中螺栓节点的真实特性。本文利用大型有限元软件ANSYS10.0对单面搭接节点和T型节点进行了非线性有限元分析,所得的有限元计算结果与国外的试验结果吻合较好。在有限元模型中,文中考虑了不同螺栓直径和不同板件厚度对单面搭接节点刚度和T型节点刚度的影响。分析表明:板件厚度和螺栓直径是影响节点刚度的最主要因素。在大量有限元分析的基础上,对螺栓连接的冷弯薄壁C型钢桁架节点的半刚性性能进行了研究。由于节点转动刚度对杆端提供了有利的转动约束,杆件的计算长度相应减小,因此节点半刚性对冷弯薄壁C型钢桁架的有利影响是显而易见的。根据有限元分析结果,拟合了考虑节点半刚性的构件计算长度公式。更多还原

【Abstract】 The web members in cold-formed steel trusses are usually assumed to have pinned connections at the ends. However, the study of the real behavior of bolted joints is not sufficient at present. The related design rules have not considered stiffness of joints in Chinese code. Based on the latest experimental study abroad, this paper works some numerical analysis, aimed at evaluating the real behavior of bolted joints in cold-formed steel trusses.In this paper the finite element program ANSYS10.0 is applied to carry out the finite nonlinear analysis of single lap joints and T-joints. The FEM models were then verified by the experimental results. In the FEM model of single lap joints and T-joints, the thickness of the plates and the effect of bolt diameter are considered. The result shows that the plate thickness and bolt diameter are main factors to influence the stiffness of joints.Based on the finite element nonlinear analysis, the semi-rigid properties of joints in bolted connected cold-forme’ steel trusses were studied. The buckling lengths of the web members will decreases, due to the rotational stiffness of joints providing rotational restraints at the end of web members. Consequently, the influence of semi-rigid joints to cold-formed steel truss is obvious. According to results of finite element analysis, a formula for calculating the buckling length of truss web members is fitted, which considers the influence of semi-rigid joints.更多还原