Influence On Prediction Accuracy Of Inherent Deformation In Short Weld

The inherent deformation finite element method is a kind of predictive welding deformation method which can solve the welding deformation of large and complex structures,and is more economical and practical.It can directly solve the practical problems in the hull construction project,and has good practical significance and application prospects..However,the inherent deformation method still has some defects.For example,the end effect has an influence on the accuracy of welding deformation prediction under short welding conditions.In hull welding,there are often short-welded structures,such as intermittent welding,stiffened vertical welding and special thin-plate components in the superstructure of luxury cruise ships,so the effects of end effects may be encountered in engineering predictions.n this paper,the finite element numerical simulation is used to firstly analyze and analyze the influence of the inherent strain on the prediction accuracy of simple short welding deformation.Then,for the typical short-welding condition structure in the actual process,that is,the vertical welding in the intermittent welding and the stiffened plate welding,the deformation obtained by the inherent strain method is compared with the thermal-elastic-plastic calculation,and the result shows that the short weld The end effect has a greater precision impact on the prediction of welding deformation.In order to explore the reasons for the influence of forecasting accuracy,the three-dimensional finite element software was used to calculate and analyze the intrinsic deformation curves along the weld direction for a series of lengths of 10 mm thick and 6mm thick plates.Combined with the welding deformation,the following results are obtained:(1)For a 10 mm thick plate,good prediction accuracy can be obtained when the inherent strain method is used to predict the welding deformation and the weld length is greater than 150 mm.For the 6mm thick plate with the same heat input condition,good prediction accuracy can be obtained when the weld length is greater than 200 mm.(2)The larger plate thickness was verified,and the thicker the plate,the more the trend was affected by the end effect.(3)The T-welding has been verified,and the critical length obtained in the buttwelding is also applicable to the T-weld with the same heat input and thickness.(4)For the short welds where the end effect cannot be avoided,a simple correction method is given.The verification of the 6mm thick and 10 mm thick plates shows that the correction method works well.