With the demand for construction of lightweight ships and polar ships, high-strength steel is increasingly applied in shipbuilding. There are a large number of complex curved plates to be processed in ship construction. The main method for forming a complex curved plate is line heating. A saddle plate is an important type of double-curved plate, which affects the resistance performance of the ship. The existing research on high-strength-steel saddle plates is lacking. To solve the problem of forming for high-strength-steel saddle plates, the numerical calculation of line heating for a EH36 steel saddle plate was studied. By combining it with a line heating experiment of low-carbon-steel saddle plates, the feasibility of numerical calculation based on the thermal elastic–plastic theory for high-strength-steel saddle plates was verified. Under the premise that the processing conditions such as the material parameters, heat transfer parameters, and the constraint mode of the plate were correctly designed, the effects of the influencing factors on deformation of the saddle plate could be studied by the numerical calculation method. The numerical calculation model of line heating for high-strength-steel saddle plates was established, and the effects of geometric parameters and forming parameters on shrinkage and deflection were studied. This research can provide ideas for the lightweight construction of ships and provide data support for automatic processing of curved plates. It can also provide inspiration for curved plate forming in fields such as aerospace manufacturing, the automotive industry, and architecture.

To solve the problem that the lack of reference for hull plate division leads to the difficulty and low efficiency of curved plate forming, the forming difficulty evaluation of complex curved hull plates is researched. Considering the characteristics in curved plate forming process, the forming difficulty evaluation model of complex curved hull plates based on grey relational analysis is established. The evaluation process of forming difficulty for curved plates is designed. The influence law of parameters and forming parameters on the forming difficulty of curved plates are revealed. The weight coefficients of different influencing factors on the forming difficulty of curved plates are quantified. Taking the real hull plate of a container ship as an example, the evaluation results for the forming difficulty of curved plates are calculated based on the evaluation model. The rationality of the evaluation model is verified by comparing the evaluation results of curved plate forming and the process time data. The research can provide a reference for the reasonable division of hull plates and reduce the forming difficulty of curved plates.