焊接残余应力对疲劳寿命影响的定量研究

摘要

在以往的研究中,残余应力对疲劳寿命的影响基本上均局限于定性分析,很少给出定量的研究结果.文章基于双参数统一方法,开展了锥柱结合壳处的残余应力对疲劳寿命的定量计算分析,给出了残余应力对疲劳寿命影响范围,并通过试样疲劳试验进行了验证.通过研究,可以看出残余应力没有改变裂纹的扩展趋势,但明显加快了裂纹扩展的过程,明显降低了耐压结构的疲劳寿命.%For most of the past researches,the effect of the welding residual stresses on fatigue life was only studied qualitatively. In this paper, based on the expression of the two-parameter unified approach, the influence of the welding residual stresses on fatigue life is investigated quantitatively in a connection joint between cone and cylinder structure. The predicted results are compared with experimental data and good agreement is found. From this research,one can obtain that the welding residual stresses can quicken the crack propagation and reduce the fatigue life,but not change the crack propagation trend.