Optimization Research For Expansion Method Of 3-D Curved

The surface of the hull is one of the main factors which affected the performance of the ship.A large number of three-dimensional curved plates need to be processed during the ship construction process.The hull threedimensional curved plate is mostly a non-expandable complex surface,which is difficult to process.Because the process flow of The hull threedimensional curved plate is complicated and difficult to control.The expansion of the curved plate is the first step of the hull three-dimensional curved plate forming process,and its unfolding effect affects the number nesting and the curved plate forming processing.The actual production of the curved plate in the shipyard was carried out by hand work drawing method.The influence of the expansion of the curved plate on the subsequent process was not fully considered,and the necessary decision support was not provided in the processing of the curved plate,which affected the efficiency of the curved plate forming process.Based on the shipyard geodesic method,this paper proposes a Constant Unit Length expansion method,establishes a multi-objective optimization mathematical model for the hull three-dimensional curved plate expansion,and uses the improved multi-objective cultural genetic algorithm to solve the problem.The non-dominated solution uses the linear weighting method or the AHP to determine the final solution.Combined with the actual method in the shipyard,the adaptability improvement of the unit isometric method was proposed,and a development method that can provide fire path layout decision support for the subsequent curved plate thermoforming process was proposed.1、This paper proposes a Constant Unit Length expansion method.According to the unfolding principle of constant unit length,the hull threedimensional curved plate is unfolded.And the shipyard geodesic method is used to determine the method of unfolding the baseline,and the Dijkstra algorithm is introduced in the process of determining the horizontal reference line.The effectiveness of the unit isometric method was verified by the deployment test of the sail plate and the torsion plate.2、Establish multi-objective optimization mathematical model for hull three-dimensional curved plate expansion problem.Through the analysis of the hull three-dimensional curved plate development,starting from the shipyard actual process,proposed the use of area error,edge linearity and unit average strain energy three indicators to evaluate the hull threedimensional curved plate expansion effect.The MOMA algorithm with heuristic operator is used to solve the hull 3D curved plate expansion optimization model.The AHP method is used to select multiple solutions to obtain the final unfolded surface.The effectiveness of the algorithm was verified by multiple sets of controlled experiments.3、Engineering application of Constant Unit Length method.According to the requirements of the hull three-dimensional curved plate thermoforming process,the Constant Unit Length method is improved,and the response speed is developed.The development result can guide the fire path layout decision of the curved plate hot forming process.