Theoretical And Experimental Study On The Neutral Layer Offset In The Straightening Process Of The Double Metal Composite Plate

With the continuous development of industry, the requirements on the mechanical properties of the structure material are constantly improving. The bimetal composite plate has been widely used in industrial production as a new type of composite material in recent years. It can improve the product performance significantly and reduce the cost of the project. Straightening is an important process in the production of a bimetal composite plate and directly relates to the quality of plates. In the traditional straightening theory, the neutral layer offset is not taken into account when calculating the straightening force and the rolling reduction are calculated. This method leads to inaccuracies of results and influences the precision of the composite plate. Therefore, it is necessary to study the neutral layer offset in the composite plate straightening process.In this paper, the composite plate production, research status and method of the neutral layer theory are formulated in the first chapter. At the same time, the research objective and contents of this paper are also described. Then the existing straightening theory is briefly studied, the calculation methods of main parameters are clarified,such as stress?strain?curvature?bending moment and straightening force of the elastic-plastic deformation during the plate straightening process. the relationship between the main parameters and bending deformation is described. In this paper, according to the characteristics of the bending deformation of the composite plate, the stress and strain are analyzed in the straightening process of the bimetal composite plate. The formula of the stress neutral layer offset is obtained and the model of bending moment and straightening force are established considering the offset of the neutral layer. In the numerical analysis phase, the neutral layer offset about the carbon steel/stainless steel composite is analyzed by the finite element method(FEM).The results show that the neutral layer of the composite plate is offset to the side of the cladding material in the straightening process. The neutral layer offset relates with the load, the thickness of the composite plate and the thickness ratio.The changed law of the neutral layer offset in a fixed time is obtained. The dynamic changed law of the neutral layer is also analyzed in the whole straightening process. Finally, with experiments, it illustrates that the phenomenon of the neutral layer offset exists. The relationship between neutral layer offset and the compression ratio is also clarified. Finally, the influence of the neutral layer offset to the straightening force precision on the composite plate straightening is analyzed. This research provides a theoretical basis for improving the straightening force precision.