Predictive and control models of the spring-back in thick hull plate forming

Hull complex plates are multidimensional curvature plates. It is difficult to adopt the traditional hot-forming method to process doubly or multiple curved plates. Multi-point forming automation equipment is a new forming process for 3D ship hull plate. However, the loading punches of traditional multi-point forming equipment are often designed in the point contact, which is easy to cause a series of defects, such as local indentations and wrinkle defects. The improved multi-point forming model with surface contact was proposed and verified with test methods. Moreover, the cold-forming process and spring-back process were simulated and analyzed with FEM for the improved multi-point forming model. The validity of the numerical method was confirmed by a series of experimental results. Finally, to ensure the forming precision, the successive approximation method was developed and verified to control the spring-back in cold-forming for curved hull plates.