平面内弯矩作用下主圆支方K型节点的应力集中系数研究

Stress concentration factor of circular chord and square braces K-joints subjected to in-plane bending loads

文中采用有限元与试验方法系统地分析了主圆支方K型管节点在平面内弯矩作用下的应力集中系数。使用ABAQUS软件进行了125组在平面内弯矩作用下节点的数值模拟,得到了K型管节点在平面内弯矩作用下焊缝区域的应力集中系数,并且对主管和支管的应力集中系数进行了系统研究,分析了节点几何参数对主管和支管的应力集中系数的影响。结果表明,β(支管与主管直径比值)和2γ(主管直径与壁厚比值)值对节点的应力集中系数影响较大,而τ(支管与主管壁厚比值)对主管和支管的应力集中系数影响较小。主管的应力集中系数值主要出现在鞍点的附近,而支管的应力集中系数值出现的位置主要由β、2γ和τ等几何参数来决定。根据有限元模型的分析结果,通过曲线拟合提出了计算平面内弯矩作用下主圆支方K型管节点应力集中系数的参数方程,并对该方程的准确性进行了评价。最后,通过节点平面内弯曲试验再次验证了本文提出的应力集中系数公式的可靠性和安全性。

The stress concentration factor of circular chord and square brace K-joint subjected to in-plane software K-joint. bending loads was analyzed using the finite element method and experiments. The general package ABAQUS was used to analyze the stress concentration factor along the welds of the The effects of different geometrical parameters on the stress concentration factor were inves- tigated. The parameters,13 and 23, hadgreat influence on the stress concentration of the K-joints, but r hadsmall influence on it. The stress concentration factor of the chord mainly appearednear the saddle, but the stress concentration factor of the brace was mainly determined by geometrical param-eters. The detailed effects of the three geometrical parameters on the stress concentration factors of the K-jointwereobtained from parametric analysis, and a set of parametric equations to predict the stress concentration factor of the K-joint subjected to in-plane bending loads wasproposed. These equations were acquired from the nonlinear regression and curve fitting technique and calibrated by the experimental results.