Fatigue strength of ship hulls has been received increasing attention due to the use of high tensile steels and the increase of stress levels of hulls. The fatigue life of ship structures is mostly dependent on the fatigue life of their weldments. It is important to know the effect of weld geometry parameters on fatigue life and know how to improve the fatigue behaviour of ship structures by practicable and economic methods.In this paper,the influence of weld geometry parameters on fatigue strength of welded structures were analysed firstly,the experiments on simple tension and fatigue specimens that made of steel ABS-A and steel 945 respectively with grinding and as-welded weldments have been performed.The experimental results show that the fatigue life of steel welded joints can be improved by grinding the weld bead,especially for the higher strength steel.The experimental results also show the great difference between manual grinding and machine grinding on improving the fatigue life of butt-welded joints and the scatters of the experimental fatigue lives are very large.The fatigue life improving processes should be studied in more detail.%由于高强度钢的使用,船舶结构许用应力水平的提高,船舶结构的疲劳强度越来越受到关注.船舶结构的疲劳寿命取决于其焊接结构的疲劳寿命.因此,了解焊缝几何参数对焊件疲劳强度的影响以及采用经济实用的方法改善船舶结构的疲劳性能是十分重要的.本文首先对焊缝几何参数对焊件疲劳寿命的影响进行了分析,在此基础上用ABS钢和945钢两种钢板做试件,分别进行了简单拉伸实验及打磨和未打磨条件下对接接头的疲劳试验.试验结果表明焊件的疲劳寿命可以通过打磨焊缝得到改善,尤其对于高强度钢焊件.试验还说明手工打磨焊缝和机械磨削焊缝对焊件疲劳强度的改善效果差别很大,疲劳寿命的分散性也很大.因此,应当对改善焊件疲劳寿命的工艺进行更详细的研究.
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