平面K型圆钢管搭接节点有限元参数分析与极限承载力计算公式  

Parametric analysis and design equation of ultimate capacity for unstiffened,overlapped CHS K-joints

作　　者：陈誉[1] 赵宪忠[1] 陈以一[1] 

机构地区：[1]同济大学土木工程学院,上海200092

出　　处：《建筑结构学报》2006年第4期30-36,共7页Journal of Building Structures

基　　金：国家自然科学基金资助项目(50578117)

摘　　要：以平面K型圆钢管搭接节点的试验数据为基础,从节点极限承载力、变形过程和破坏模式等方面对搭接节点的非线性有限元建模方法进行了校验。重点考察了贯通腹杆受压且内隐蔽部分焊接的搭接节点的应力分布、塑性区扩展和破坏模式,以及几何参数、腹杆搭接顺序变化、内隐蔽部分焊接与否对各类搭接节点性能的影响。有限元参数分析结果表明,腹弦杆壁厚比的变化对搭接节点的破坏模式和承载性能影响较大;内隐蔽部分未焊接对贯通腹杆受压的节点极限承载力影响很小,但对贯通腹杆受拉的节点极限承载力影响很大。最后,在零间隙节点承载力计算公式的基础上,应用多元线性回归方法拟合出搭接节点的极限承载力计算公式;该公式与试验结果吻合良好,且具有较好的适用性。A finite element model simulating the experiment on unstiffened, overlapped CHS K-joints was generated and validated by comparing the ultimate capacity, deformation process and failure mode with experimental results. Using this model, the stress distribution, propagation of plasticity and the failure mode of overlapped joint with through-brace-incompression and welded hidden seam were studied. The effect of geometric parameters, with or without hidden weld, and loading hierarchy reversal of braces on the ultimate capacity of the joints was also studied. The results of FE parametric analysis indicate that brace-to-chord thickness ratio has relatively large effect on the failure mechanism and ultimate capacity of overlapped joints; the absence of hidden welds has less significance on the ultimate capacity of the through-brace-in- compression joint than on that of through-brace-in-tension joint. Finally, based on the design equation of gap joint, a formula predicting the ultimate capacity of overlapped CHS K-joint was proposed by applying multivariate regression analysis. Results calculated using the proposed design equation agree well with experimental results.

关 键 词：K型圆钢管搭接节点 极限承载力 有限元分析 参数分析 

分 类 号：TU392.3[建筑科学—结构工程]