Numerical Simulation Of Multi-Point Forming For Curved Hull Plate

In the time of comprehensively shift toward to automation and digitization inshipbuilding industry, traditional line-heat forming is still the general way for curvedhull plate forming in shipyards. Because of strong labor intensity and low productionefficiency, line-heat forming has seriously impeded the rapid development ofshipbuilding industry. As a new flexible forming technology, Multi-point forming(MPF) will improve forming precision, work efficiency and reduce production cycle. Ithas a broad prospect of application in the field of shipbuilding.In the paper saddle and sail shape were selected to be samples in the simulation ofMPF process of loading and unloading for curved hull plate with Finite ElementMethod. The influence laws of materials, thickness and curvature of formed hull plate,chosen as variables, were studied. In addition, the non-wrinkling forming limits ofsaddle and sail shape were obtained. In order to prevent wrinkling, the preventionmeans of elastic cushion and Multi-step forming (MSF) were proposed and verifiedusing simulation in the paper.With the advantages of light weight and high strength, high strength steel platemeets the requirements for security and reliability. But it can’t be formed due to thehigh strength at room temperature. FEA model of hot stamping for high strength hullplate of A36was established in the paper. Contrast to traditional cold stampingtechnology, the forming limit of A36was greatly improved in hot forming. With thedefects of wrinkles and springback restrained in hot stamping, precision forming ofhigh strength hull plate was achieved. And so it provides some reference for practicalapplication in production of high strength hull plates.With flexible properties of MPF, large size parts can be formed with sectional MPF with small equipments. So it provides a new way for forming of large hull plate.In the paper FEA model of sectional MPF for sail part was established. It is verifiedthat sectional MPF has more advantages than general MPF in the forming of large hullplate. Contrast to different design of transitional region, it is concluded that wrinklescan be effectively restrained, and the forming quality is improved by reasonable designfor transitional area.