Research On The Test Of Measuring Welding Residual Stress And Deformation Of Plate Of Moderate Thickness

With the welding process widely used in ship construction, the deformation andstrength character of welded structure become the focus of experts from all over the world.Since numerical simulation method can comprehensively reflect the overall performanceof engineering structures, it had become an important means for the research of weldedstructures. However, before the numerical simulation method effectively used in weldedstructures, the calculated results of this method should be verified by the actual test results.Therefore, accurately measuring results is an important prerequisite to verify the validityof the numerical simulation method.First of all, theory and selection method of related parameters of hole-drilling method,which involved to measuring the welding residual stress acting onthe surface of thespecimens are introduced. The experimental parameters are optimized according to theactual conditions. By measuring prefabricated residual stress pieces, strain reliefparameters A and B of two different steels are verified, and then the residual stress actingon the surface of two welded specimens is measured respectively. By analyzing theexperimental data many results are obtained, including the distribution state of bothlongitudinal and transversal stress along the welding direction and the directionperpendicular to the welding direction respectively as well as the relationship betweenmaximum residual stress and yield strength, etc.Then the theoretical derivation of layer-removal method, which used to measure theinternal residual stress of rectangular cross-section beam are introduced. The applicationof this method to measure the internal residual stress of welded specimens, which not onlyconducted a preliminary exploration of the measurement method but also draw thedistribution state of residual stress along the direction of thickness. Besides, Non-contact measurement methods of welding deformation are discussed.And then the welding deformation of several specimens were measured based on machinevision measuring method, thus obtained a group of welding deformation parameters.Finally, the adopted measuring methods used in this paper were discussed and theanalysis come to various factors that affect the measurement accuracy, pointing out thelimitations and inadequacies of the methods, which propose the research to be done in thefuture.