弹性阶段低匹配对接接头三点弯曲余高形状设计

Shape design of reinforcement for under-matched butt joints under three-point bending load in elastic stage

关键词:  高强钢  低匹配对接接头  等弯曲承载能力  余高形状设计  有限元验证

Key words:  high strength steel  under-matched welded joints  equal bending load-carrying capacity  shape design of the reinforcement  finite element verification

摘要:

弹性阶段以提高低匹配接头弯曲承载能力为目标,基于材料力学方法针对三点弯曲时低匹配对接接头的余高形状设计,提出了等弯曲承载能力(EBLCC)的设计思想、判据及实现条件,并给出了三点弯曲接头余高形状设计方案,同时对理论分析结果进行了有限元验证.结果表明,理论计算余高形状为抛物线形,有限元结果与理论分析基本吻合,EBLCC设计使峰值应力从低匹配接头承载薄弱的焊缝区转移到近焊趾的母材部位,从而提高了低强焊缝的弯曲承载与抵抗弯曲变形能力.余高双侧对称圆弧型可以替代抛物线型.这种设计方法对高强钢低匹配对接接头设计及应用具有参考和指导意义.

Abstract:

In order to improve the equal bending load-carrying capacity(EBLCC) of under-matched butt joints in the elastic stage, the shape design of the reinforcement was investigated based on materials mechanics under three-point bending load.The design idea, criterion and realization condition of EBLCC were put forward.Two design methods for the reinforcement shape were proposed after theoretical calculation of under-matched butt joints under three-point bending load.The theoretical analysis results were verified by the finite element method.The research results showed that the reinforcement shape from theoretical calculation was parabolic.The finite element results were basically coincident with the theoretical analysis.The vulnerable area of under-matched welded joints can be transferred from the weld bead to base metal near the weld toe after the shape design of the reinforcement of EBLCC, which improved the bending load-carrying and resistance to bending deformation capacity of under-matched butt joints.The arc shape can replace the parabolic shape for the double-side symmetric reinforcement.The proposed shape design method has potential application in the design of under-matched butt joints of high strength steels.