平面内弯矩下Y型主方支圆钢管节点热点应力集中系数

Hot spot stress concentration factor for tubular CHS-to-RHS Y-joints under in-plane bending

文中采用有限元方法对平面内弯矩作用下的Y型主方支圆钢管节点进行数值分析,建立152个不同几何参数的Y型主方支圆钢管节点有限元模型,在模型中精确考虑主管和支管间焊缝的复杂几何形状。基于有限元分析结果,计算节点热点应力及热点应力集中系数,通过与文献试验结果的对比验证了数值分析结果的可靠性。对主、支管间焊缝的热点应力集中系数分布进行分析,结果表明,不同几何构型节点热点应力集中系数的分布形式基本相同,热点应力集中系数在?=0°(冠趾)、?=135°及?=180°(冠根)等关键位置达到最大值。讨论几何参数对关键位置热点应力集中系数的影响,并通过回归分析建立计算Y型主方支圆钢管节点关键位置热点应力集中系数的经验公式。经验公式结果与有限元分析结果吻合度较高,用经验公式计算Y型主方支圆钢管节点关键位置热点应力集中系数具有较高的准确性。

In this work, the tubular CHS-to-RHS Y-joint under in-plain bending was studied by finite element method. Finite element models with detailed weld profile were generated for a total number of 152 tubular CHS-to-RHS Y-joints with various configurations. Hot spot stress and hot spot stress concentration factor （SCF） were determined based on the results of finite element analysis, which were verified by comparing with related test results. HSSCF distribution along the weld between chord and brace was discussed. It is found that SCF distributions of Y-joints with various configurations are almost the same. The maximum value of SCF occurred at polar angle p=0° （crown toe）, p=135°or p=180° （crown heel）. The effects of dimensionless geometric parameters on SCFs at these feature locations were studied. Empirical formulas were established for the calculation of SCF at feature locations of tubular CHS-to-RHS Y-joints, by regression analysis. The SCF calculated by empirical formulas agreed very well with the results of finite element analysis. Therefore, SCF at the feature locations of tubular CHS-to-RHS Y-joints under in-plane bending can be determined accurately by the presented empirical formulas.