| Sumario: | Abstract: Plate forming by line is an efficient and economical method for forming flat metal plates into doubly curved shapes. This thesis proposes an accurate method to predict heat-hinducd deformation that enables automation of process of plate forming by line heating. Sice the analysis of the line heating process is highly complex either, experimentally of using simple mechanical models, a 3D thermal elastic-plastic finite element analysis (FEA) is established first. Using this FEA, plate deformation caused by heating lines over large plates such as those used in shipbuilding (as opposed to the small plates investigated in existing research) is accurately predicted. The deformation under the line heating process is mainly affected by the heat input, the speedof heat source and the thickness of the plate. Thus, the relation among these parameters are examined in details. The influences of the secondary parameters affecting the line heating process such as size of the plate, material, propierties, location of heating lines, heat-induced curvature, inter-heating temperature, cooling conditions and residual stress on the deformation produced by a single heating line then clarified. The influence of overlapped, parallael and crossed heating lines on deformation of multiple heating lines successfully investigated. New methods to increase the deformation at plate edges are proposed. Finally, the relations between heat induced deformation and influential factors are investigated parametrically as inherent deformation database for a wide range of plate geometries and heating. Compared with conventional methods, this database takes into account the deformation produced by multiple heating over large plates. Based on this database, it is possible to not only determine the heat-induced deformation produced by a given heating condition, but also determine the correction factors that are necessary to improve the accuracy of the process of forming flat plate into a doubly curved plate. This database lays the basis for heat-induced deformation ptediction and therefore the automation of plate forming by line heating.
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