剪力作用下大型钢箱梁极限承载力研究

Study about Ultimate Bearing Capacity of Large Steel Box Girder under the Action of Shear Force

现行GB50017-2003《钢结构设计规范》对焊接箱形截面梁极限承载力规定还比较粗糙,本文考虑材料非线性、几何非线性和箱梁初始缺陷的影响,采用对Nweton-Raphson公式进行修正的弧长增量法求解剪力作用下焊接箱梁极限承载力,并通过模型试验,验证了计算方法的正确性.通过大量的数值模拟仿真计算,归纳总结出了箱形截面梁在剪力作用下稳定极限承载力计算公式.该公式把极限承载力与腹板高厚比、翼板宽厚比直接关联起来,对焊接箱形截面梁稳定极限承载力的计算及设计具有参考价值.

The rules about the ultimate bearing capacity of the welded box girder in the current GB50017--2003 ＂Structural Design Specification＂ are faulty. The influences of the material non-linearity, geometrical non-linearity and the initial defect are considered in this paper. The arc length increment method obtained by revising Newton-Raphson formula is used to solve the ultimate bearing capacity of welded box girder under the action of the shear force, and the correctness of the calculation method is validated through the model tests. The formula used to calculate the stable ultimate bearing capacity under the action of the shear force of the box girder is summarized through large of simulation calculations. The method relates di- rectly the ultimate bearing capacity to the height to thickness ratio of the web and width to thickness ratio of the wing plate,which has the reference value to calculate and design the stable ultimate bearing capacity of the welded box girder.