Ultimate Bearing Capacity of Hollow Spherical Joints Welded with Circular Pipes under Eccentric Loads

The hollow spherical joints welded with circular pipes applied to the National Swimming Center of China are subjected to large bending moments, but the influence of bending moments is not considered in the design equations in Technical Specification for Latticed Shells. Based on the von Mises yield criterion, multilinear isotropic hardening rule and associated flow rule, the elasto-plastic finite element model is put forward to analyze the behavior of the joints, and a calculation method for the joints under bending moments or eccentric loads is proposed. It is shown by the analytical results of joint that the stiffening rib can improve the ultimate bearing capacity by 10% for joints under axial tensile load, by 40% for joints under axial compressive load, and by 50% for joints under bending moment. The unified calculation equations for joints with or without stiffening rib are put forward, which can be applied to calculating the ultimate bearing capacity of the hollow spherical joints with circular pipes under eccentric loads.

鼓形双肋焊接空心球节点承载力研究

采用计算机数值计算结合试验研究的方法分析鼓形双肋焊接空心球节点的承载安全性能,得到鼓形双肋焊接空心球节点的力–位移曲线关系,得出了节点极限承载力,并对该节点的安全性进行评估。

具有加劲肋的焊接球节点刚度分析(英文)

空间网壳结构的节点是半刚性的,节点刚度对大跨度网壳结构的稳定承载能力有着重要的影响.按节点完全刚接或完全铰接计算会过高或过低地评价结构的稳定承载能力.而具有加劲肋的焊接球节点被广泛应用在大跨度空间网壳结构中.本文采用有限元软件ANSYS对具有各种不同形式加劲肋的焊接球节点轴向刚度和弯曲刚度进行了分析,并与无肋焊接球节点进行了比较.通过回归分析,得出了具有各种不同形式加劲肋的焊接球节点轴向刚度和弯曲刚度的实用计算公式.本文为考虑节点刚度的大跨度网壳结构稳定分析提供了理论基础,并得出了可应用于实际工程的结论.

球外加肋加固既有网架焊接空心球节点的非线性数值分析

设置加劲肋是提高焊接空心球节点承载能力的一个有效途径,但是在球内设置加劲肋对于既有网架节点加固来说十分困难。球外设置加劲肋可能是加固既有网架结构节点的一个可能途径。本文基于数值模拟的方法对球外设置加劲肋加固网架球节点的受力变形和破坏过程进行了分析。在数值模拟中考虑了几何非线性和材料非线性两种非线性效应。以某实际工程加固为依托,研究了空心球节点在单向受力状态和空间复杂受力状态两种情况下的受力和变形特征,对焊接空心球节点的加固前后的破坏过程进行了对照分析,给出了环状肋加固球节点的承载力提高系数。