Curvature Analysis Method for Ship-Hull Plate Forming

Ship-hull plate forming by line heating requires hard and skillful labor. Initially, the plate is curved in one direction by rolling. Then, the curved plate is transported to the line-heating workshop to obtain the required shrinkage. However, this two-step forming leads to a series of problems. This paper presents a method to change the two-step forming into line-heating forming by using curvature analysis. The principal curvatures of the formed plate can be calculated directly from the offset data. The principal curvature distribution provides information on the deformation distribution and the heating lines. Heating along a line will result in a uniform bending angular deformation. A numerical method to determine the heating lines to produce the required bending angle is presented. This kind of heating line does not require adjustment of parameters in line heating. It would benefit temperature control and facilitate plate forming automatically.