CAJ | 학술논문

对于承受交变载荷的焊接构件，焊接残余应力的存在对于结构的疲劳寿命影响巨大。由于焊接残余应力形成机理的复杂性，当交变载荷作用时，焊接残余应力的松弛演变具有不确定性，导致该领域的研究难度相当大。迄今为止，鲜有文献就交变载荷下的厚板焊接残余应力松弛行为进行深入报道。采用低周疲劳试验，利用X射线残余应力测试仪，对试件表面焊接残余应力的松弛演变行为进行追踪研究，通过在试件表面近焊缝区布置网状测点，采集测点的横向及纵向焊接残余应力进行数据拟合，在试验对比修正的基础上，最终建立焊接残余应力的松弛演变模型。结果表明：在交变载荷作用下，焊接残余应力会发生松弛，并且，应力松弛量的大小与交变载荷的特征值大小紧密相关。
대우승수교변재하적한접구건，한접잔여응력적존재대우결구적피로수명영향거대。유우한접잔여응력형성궤리적복잡성，당교변재하작용시，한접잔여응력적송이연변구유불학정성，도치해영역적연구난도상당대。흘금위지，선유문헌취교변재하하적후판한접잔여응력송이행위진행심입보도。채용저주피로시험，이용X사선잔여응력측시의，대시건표면한접잔여응력적송이연변행위진행추종연구，통과재시건표면근한봉구포치망상측점，채집측점적횡향급종향한접잔여응력진행수거의합，재시험대비수정적기출상，최종건립한접잔여응력적송이연변모형。결과표명：재교변재하작용하，한접잔여응력회발생송이，병차，응력송이량적대소여교변재하적특정치대소긴밀상관。
For welded structures subjected to dynamic loadings, the welding residual stress has tremen-dous influences to the structural fatigue life. However, due to the complexity of the welding residual stress and the uncertainties of the welding residual stress relaxation under alternating loads, the residual stress re-laxation research can be rather difficult. So far, only few researches have been conducted within this area to study the relaxation and redistribution of the welding residual stress in thick plates, especially for the weld-ed structures under dynamic loadings. Under the low-cycle fatigue loading conditions, an experiment is car-ried out on a thick welded plate of 100 mm;with help from X-ray stress testing apparatus to, the process of how alternating loads affect the redistribution of residual stress is analyzed. By arranging the test points around the welding line, a series of data inputs of residual stress is obtained, with which a time-varying re-distribution regarding the surface residual stresses relaxation is presented. It is concluded that residual stress distribution can be changed by the alternating loads, and the alternating loads do contribute to the re-distribution of the residual stress field.