支管轴力作用下T形圆管节点热点应力分布研究

Research on hot spot stress distribution of CHS T-joints under brace axial loading

对支管轴力作用下的T形圆管相贯节点焊缝处热点应力分布开展研究,并提出了其应力分布曲线方程。利用径向拉伸法建立了T形圆钢管相贯节点的有限元网格模型,对焊趾处热点应力分布的计算结果进行了可靠性分析,并将三种不同密度网格模型的应力分析结果与试验结果对比表明基本网格密度满足计算精度要求。分析了T形圆钢管相贯节点在支管轴力作用下的热点应力沿相贯线的分布规律,考查了四个无量纲几何参数对应力分布曲线形状的影响,在此基础上拟合并确定了基于三角正弦函数的曲线修订公式。经与UCL公式和试验数据的对比统计分析,表明该曲线修订公式具有更高的精度。

Hotspot stress is one of the critical stress indicators for evaluating the fatigue performance of joints.This paper investigated the hotspot stress distribution at the weld of CHS T-joints under the brace axial force and proposed its stress distribution equation.Finite element models of the CHS T-joints were established using the radial extension method,and the reliability of the calculated results of the hotspot stress distribution at the weld toe was analyzed.By comparing the stress analysis results of three grid models with different densities with experimental results,it is shown that the basic grid density meets the calculation accuracy requirements.The distribution pattern of the hotspot stress along the intersection line of the CHS T-joint under the brace axial force is analyzed,and the influence of four dimensionless geometric parameters on the shape of the stress distribution curve is examined.Based on this,a curve revision formula based on the trigonometric sine function is fitted and determined.Compared with the UCL formula and experimental data,the statistical analysis shows that the formula proposed in this paper has higher accuracy.