双向轴力作用下焊接空心球节点有限元模型的建立

Finite Element Modeling on Welded Hollow Spherical Joints Subject to Bi-axial Forces

焊接空心球节点广泛应用于网架和网壳结构中,目前有关焊接空心球节点的计算公式都是在单管相连焊接空心球节点的基础上给出,而实际工程中的焊接空心球节点都是与多管相连.该文以四管焊接空心球节点为研究对象,首先根据四管焊接空心球节点的受力特点,给出其在轴力作用下的简化力学模型,在综合分析材料、网格密度、壳单元和实体单元优缺点的基础上建立了有限元模型.

Welded hollow spherical joints are one of the most popular nodal joints in space trusses and lattice shells,with the advantages of simple construction,definite load transferring mechanism and convenient connection.The present practical calculation method is established based on the spherical joints connected with single-tube.But the spherical joints used in engineering are connected with more tubes.The spherical joints with two tubes are studied in the paper.Finite element analysis and mechanical model are carried out to investigate the structural behavior of welded hollow spherical joints subject to bi-axial forces.The two finite element models,one adopting the shell element and the other solid element for the analysis of these joints,are established.A major parametric study is carried out by employing the models.The analytic results show that,for welded spherical joints when t/d≥0.05,the solid element is the first choice for the model.