The Research Of Straightening Process Of Stiffened Thin-Plate Structure Welding Deformation Based On Induction Heating

As the most common jointing method in the current shipbuilding process,welding hasthe characteristics of high temperature and concentrated distribution,which tends to cause a certain degree of welding deformation and residual stress after welding.In order not to affect the normal use of the welded components and the aesthetics of the ship,it is generally necessary to adopt a thermal leveling method to correct the weld deformation and residual stress of the weldment.The traditional method is to use flame heating,but due to the low heat efficiency,difficult control,poor sheet correction,etc.,people gradually apply electromagnetic induction heating technology with “skin effect” to ship construction.It has a good corrective effect on the welding deformation of the thin plate.Thin plates are widely used in ship superstructures,but the deformation of thin plates due to welding is often more variable and complicated.In order to effectively correct and control the welding deformation of the thin plate structure,the moving induction heater is selected as the heat source for thermal leveling,and the most common stiffened plate structure in ship construction is selected as the research object,based on the ANSYS finite element numerical value.The simulation software establishes a two-way welding finite element model of the stiffened plate structure and a finite element model of the mobile induction heating,and performs numerical simulation calculation to obtain the welding temperature field,the induction heating temperature field,the welding deformation field and the induction heating deformation field.Firstly,the temperature distribution law of induction heating and the thickness d of the steel plate panel,the current magnitude I of induction heating,the current frequency f,the moving speed v of the inductor,the influence of four induction heating parameters on the heating temperature,and the vertical heating line are studied.The temperature distribution of the direction is fitted by Gaussian function to obtain the characteristic parameters of the function.Based on the support vector machine algorithm(SVM-Support Vector Machine),the mathematical prediction model is established,and the accurate prediction of the characteristic parameters is realized.Regular research provides new ideas.Secondly,the deformation characteristics and deformation forms of the welding deformation and induction heating deformation of the stiffened plate structure are studied.Based on the SVM,the input quantities of d,I and f are established to induce.The heating correction amount is themathematical prediction model of the objective function,and finally the purpose of accurately predicting the amount of induction heating correction is realized.The results show that the mathematical prediction model based on SVM can better solve the prediction of induction heating temperature and the prediction of induction heating correction,which are high-dimensional nonlinear problems;finally on the basis of considering the post-weld residual stress,the induction heating correction is carried out on the stiffened plate structure with welding deformation,and the optimal induction heating parameters are searched for different plate thicknesses.The final deformation amount is compared with the welding deformation amount,and the induction heating process is used for the longitudinal residual of the structure.These two aspects describe the correction effect of stress distribution and the results show that the welding deformation of the thin plate can be effectively corrected by adjusting the induction heating parameters.