Study On Technical Parameters Of Marine Curved Plate Forming By Line Heating

In the domestic shipyard, the fabrication of marine curved plate is still manually operatedby experienced workers using line heating process. The produce scale and the quality of thisprocessing method cannot meet the needs of a modern shipbuilding. The core problem aboutthe automation of curved plate forming in line heating is to determine the machiningparameters. It is the key to establish the relationship between the processing parameters andthe deformation parameters through the scientific method, which thereby determines themachining parameters.This thesis studies how to determine the processing parameters of the curved plateforming in line heating. Firstly，according to the finite element simulating, the ANSYS finiteelement model and the related simulation program are established and the line heating processof the curved plate is simulated. Secondly, using the fishbone diagram, the influence factorsof the line heating temperature fields are listed, the relationship between the influence factorsand the highest temperature of plate surface are analyzed through the finite elementsimulation results and two-level fractional factorial method, which identifies the decisiveinfluencing factors in the temperature fields. Thirdly, the possible influence factors of the lineheating deformation are listed by the fishbone diagram and the influential factors of the lineheating deformation are determined through the existing theory and research results. Based onthe16sets of data from the orthogonal experimental design and the finite element simulationresults, the mathematical formula is established to display between the main influenceparameters and deformation parameters (lateral contraction and angular deformation) of thecurved plate forming with the line heating through the gene expression programming, whichthen confirms the most important influence factors of deformation—the thickness of theheated plate, the flow of acetylene, the moving speed of a heat source and the heating linearlength respectively. Finally, by comparing GEP with the method of Kriging and Neuralnetwork approach, the feasibility and availability of the GEP method are proved.This paper establishes the mathematical model between the main influence parametersand deformation parameters of the curved plate forming in line heating, which not onlyachieves the instructional meaning in the automation of curved plate forming by the lineheating technically, but also can be expounded to serve as a reference for curved plateforming by the line heating in the theory and practice.