Research On The Ship Surface Piecewise Plate Reconstruction And Unfold Technology

With the development of the computer, in the fields of automotive, aircraft,shipbuilding and other engineering and manufacturing, the unfold technology of space surface become important part in size selection of rough machining and product design. According to the demand of shipbuilding the ship need to be segmented machining, thus the automation of ship surface segment plate machining process has become a hot issue in the shipbuilding industry. Nowadays the fire and water processing technology of shipyard cannot forming ship steel at a time, it plays a important role in improving efficiency and utilization if you can provide accurate and effective processing data for the ship surface segment plate. The development of Computer Aided Design(CAD) technology and adoption of advanced manufacturing technology is the important basis for automated processing of ship steel.In this paper, the non-uniform B-spline tool is commonly seen in graphics and used in the ship surface segment plate reconstruction. Adjust control points at both ends of the boundary conditions through non-uniform B-spline curve,it can quickly achieve the non-uniform B-spline curve and surface inverse by inverse computation,expanded B-spline surface to realize reconstruction of ship surface segment plate.Then divide surface mesh based on surface reconstruction, combine the adaptive meshing with Delaunay triangular mesh to achieve triangular division meshing. Aim at the representative plate like sail-shaped plate and saddle plate of ship surface segment plate, use least square method to estimate Gaussian curvature of reconstructing parametric surfaces, obtain the Gaussian curvature cloud, it can provide a reference for accuracy of the meshing results, unfold the adaptive meshing and common polyhedral meshing, compare the results of the area of error achieved to insure the practicality of adaptive meshing.Build optimal value for solving equations based on the side length constraints of adaptive triangular mesh after getting the results of the adaptive triangular mesh,,adjust the side length value of the triangular mesh on unfold plane in order to obtain accurate curved surfaces unfold graphics. Use the commonly application of mature triangular mesh expansion method of shipyard to unfold the surface, compare the area error changesof the ship surface segment plate in order to verify the accuracy of the unfold method based on the side length constrain.