Research On Deformation Prediction Of Steel Plate Due To Multi Heating Lines Induction Heating Based On Inherent Strain Method

Due to the advantages of high efficiency,good controllability,and high speed,high-frequency induction heating of steel plates has been studied by more and more scholars.Thermal elastoplastic method is mostly used in the study of induction heating deformation of steel plate,but the situation of induction heating with multiple heating lines is more complicated.If the thermal elastoplastic method is used to predict it,the calculation is very great and very difficult.Therefore,it is possible to use the inherent strain method to make the rapid calculation of the deformation of steel plate by induction heating.In this paper,the basic theory of inherent strain of welding is introduced.The calculation of inherent strain of welding and the loading mode of inherent strain are expounded in detail.Considering the hardening problem of the steel plate during the heating process,a comparison is made between the bilinear hardening model and the ideal elastoplastic model,and the influence of material model on the inherent strain calculation of induction heating of steel plate was analyzed.Both steel plate welding and induction heating are thermal processing,and the elastoplastic process is the same.Therefore,the inherent strain method is also suitable for deformation prediction of induction heating of steel plates.In view of the characteristics of induction heating of steel plates,this paper proposes a two-bar model as an analytical model for deducing the inherent strain of induction heating of steel plates.Two of the bars represent the heating zone and the confinement zone of the steel plate,and the other parts are rigid body zones.The ideal elastoplastic model was selected as the material model to analyze the thermal elasto-plastic changes in the induction heating process of the steel plate.With the maximum temperature reached by the steel plate as the boundary,the corresponding calculation formula for the inherent strain of the induction heating of the steel plate was obtained.The study of the inherent strain region of steel plate induction heating adopts thermal elasto-plastic method,using finite element analysis software ANSYS,using node coupling technology to establish electromagnetic-thermal-structure coupled numerical model of moving plate induction heating,and carrying out numerical simulation of moving induction heating of steel plate.By analyzing the induction heating temperature of the steel plate,the shape of the inherent strain region is determined,and the calculation is simplified as a semi-oval shape and an inverted trapezoid for convenience of calculation.Through the analysis of several sets of simulation schemes,it can be seen that the characteristic values of the inherent strain region are related to the technological parameters of the induction heating of steel plates.The experimental method and numerical simulation method are used to study the induction heating deformation of the steel plate.Due to the interaction between the heating lines,the induction heating deformation of the steel plate is slightly larger than that of the single heating line,and it is related to the distance between the heating line.The inherent strain region of the induction heating of the steel plate with multiple heating lines is obtained by post-processing.The interaction of multiple heating lines leads to the change of the inherent strain region of the steel plate,which leads to the change of deformation.Considering the influence of multiple heating line induction heating on the inherent strain region,the influence coefficient of the inherent strain region of multi-heating line induction heating is proposed in this paper.When the inherent strain method is used to calculate the induction heating deformation of multi-heating line of steel plate,the influencing coefficient is applied to the inherent strain region.Therefore,the method can accurately predict deformation.The inherent strain is integrated along the inherent strain to obtain the equivalent load,which is then loaded on the steel plate model,and the induction heating deformation of the steel plate is obtained after a single elastic calculation.The deformation value of the single heating wire induced heating based on the inherent strain equivalent load method was compared with the experimental value,and the accuracy of the inherent strain mechanical model of induction heating was verified.Finally,the induction heating deformation of the steel plate with the inherent strain method is also verified.The results show that the influence coefficient is reasonable and accurate for the inherent strain zone of the multiple heating lines induction heating.