The double-curved plates forming is an important task in shipbuilding, and the line heating plate forming method is the traditional complex curved plate forming process. This paper proposes the double-sided electromagnetic induction line heating process used in plate forming. By using this process, the in-plane shrinkage deformation is decoupled from the bending deformation. Using the thermo-elastic-plastic finite element method, we study the characteristics of the double-sided heating processing under the conditions of different process parameters and different initial curvatures.
The curved surface plates forming is an important work in shipbuilding, and the line heating process is the traditional process of plate forming and processing complex curved surfaces with bidirectional curvature. With the development of manufacturing technology in shipbuilding, the electromagnetic induction line heating method is widely used in shipyards. In the line heating process, various deformations such as transverse bending, transverse shrinkage, longitudinal bending, and longitudinal shrinkage are usually produced.
There have been many published studies on the processing of line heating. Ueda (1994) studied the characteristics of line heating processing, gave the application of line heating process is actually curved plate forming, and proposed to use the inherent deformation to describe the processing. Vega (2008) studied the mutual influence between different heating lines when they are superimposed on each other, and gave the deformation influence regularity when the paths are superimposed. Lee (2013) investigated the line heating-induced permanent deformation behavior of thick plate through both numerical analysis and experimental testing by applying high-frequency induction heating. Zhu (2018 and 2019) proposed to use electromagnetic thermal full coupling finite element method to simulate the electromagnetic induction line heating process, and a simplified calculation method using a simplified surface heat source is proposed. The results of the simplified calculation and the fully coupled calculation are compared, and it is concluded that the simplified calculation can improve the calculation efficiency while maintaining the calculation accuracy. Dong (2018) investigates the width of induction coils in line heating processing and concludes that a larger induction coil can improve the processing efficiency. Zhao (2017) proposed to combine line heating and roller bending for surface processing. By combining different machining tools with each other, a richer deformation can be produced.