轴弯比对矩形钢管单层网壳双节点体系转动刚度的影响

Effect of axial force-to-moment ratio on rotational stiffness of double-node system for single-layer rectangular hollow section latticed shells

针对矩形钢管单层网壳中的双节点体系,提出一种基于节点传力方式的简化分析模型,利用该模型推导了在小偏压、大偏压或大偏拉以及小偏拉三种受力状态下节点初始转动刚度与轴弯比的关系函数,并采用实体单元有限元分析结果对其进行验证。结果表明:转动刚度随轴弯比的变化可分为与其受力状态相对应的三个阶段,即转动刚度为常数的小偏压阶段、转动刚度为轴弯比反比例函数的大偏压或大偏拉阶段和转动刚度又为常数的小偏拉阶段。在此基础上,提出基于ANSYS-MATLAB联合分析的半刚性节点杆件模型修正方法,可在双节点体系矩形钢管单层网壳整体分析的杆件单元模型中考虑轴弯比对节点转动刚度的影响;通过算例分析验证了修正方法的有效性。

Based on the force transferring pattern of node,this paper proposed a simplified analysis model of double-node system for single-layer rectangular hollow section latticed shells.In view of the node loading states under small eccentric compression,large eccentric compression/tension and small eccentric tension,a mathematical function was derived to describe the relationship between node initial rotational stiffness and axial force-to-moment ratio and verified through the finite element results.The variation of rotational stiffness with axial force-to-moment ratio can be divided into 3 stages;that is the small eccentric compression state where the rotational stiffness is a constant,the large eccentric compression/tension state where the rotational stiffness is an inverse proportion function of axial force-to-moment ratio and the small eccentric tension state where the rotational stiffness is a constant again.According to this conclusion,this paper proposed a correction method for member model of semi-rigid node on the basis of combined ANSYS-MATLAB calculation,which can account for the effect of axial force-to-moment ratio on rotational stiffness in integral structural analysis of latticed shells.The effectiveness of this method was verified by a numerical example.