Geometrical approach for flame forming of single curved ship hull plate

Ship hull plate forming by flame torch plays an important role in shipbuilding process. In shipyards, the line heating method is one of the major processes carried out by workers to form the plates into desired shapes. Since this process depends on the skilled workers’ experiences and knowhow, there is a lot of variation in the products. There also could be some difficulties in communicating with each other. Hence, it is necessary to develop an automation system to increase not only the plate forming productivity, but also product quality. For automated plate forming, it is required to know where and how much to heat on the plate. Thus, the inverse problem should be solved to obtain process parameters such as torch travel speed and the heating positions. In this study, the deformed curve shape by flame heat was geometrically considered so that the appropriate geometrical parameters can be obtained. Then, the relationship between the bending angle and the radius of the curvature of the deformed curve shape were established. In addition, the process parameters were obtained by using the relationship between geometrical parameters and process parameters. Lastly, experiments of the two-dimensional plate forming considering deformed curve shape with the curvature were performed. The results of the formed shape were similar to the target shape.