装载机焊接接头的疲劳强度及焊缝尺寸的影响

THE FATIGUE STRENGTH OF THE WELDED JOINTS IN THE LOADER AND THE EFFECT OF THE WELD DIMENSION ON THE STRENGTH

装载机的工作装置主要为焊接结构。本文根据某新型国产装载机工作装置的实际结构，模拟简化了七种焊接接头，试验研究了这些接头的疲劳强度，给出了不同接头的１０条Ｓ—Ｎ曲线；同时还就焊脚尺寸对不同载荷形式下十字接头及丁字接头疲劳强度的影响进行了研究，对不同载荷形式下临界焊脚尺寸的大小进行了讨论；并根据试验所得Ｓ—Ｎ曲线及国产装载机动臂的实际载荷谱，对三种机型动臂的疲劳寿命进行了估算，估算结果有力地支持了国产新型装载机工作装置的优化设计。

The working device of the loader is mainly welded structure,In this paper,7 kinds of joints weredeveloped based on the actual welded structures of the working device. The fatigue strength of the joints wasinvestigated and 10 S N curves of the different joints were obtained. The effects of the weld dimension on thefatigue strength of the cruciform joints and fillet joints under different loading conditions were studied and thecritical weld dimension was discussed.Upon the S N curves acquired above and the actual load program,thefatigue lives of 3 kinds of loader's moving arms were predicted,the results can be used for the optimum design ofthe working device of the new loader.