| This paper presents Improved Frame-Curvature Unfolding Method of the complex curved hull plate, based on Geodesic Method and Every bid Frame-Curvature Method with line heating forming. This method meshes the complex curved hull plate, and unfolds every grid by Improved Frame Curvature Method, lastly splices the unfolding grids onto a plane. For the Saddle Plate, the method can obtain the frame curvature, deflection angle and unfolding length of each grid to unfold the complex curved hull plate, and ultimately obtain the unfolding plane without cracks. For the Sail Plate, the method can unfold the complex curved hull plate with forming length of the grid, and obtain the unfolding plane with cracks. In the case that cracks of both sides are not balanced, the method optimizes the geodesic curve by the way of coordinate rotation to make the unfolding result even better.Based on the Improved Frame Curvature Method to unfold the complex curved hull plate, the paper presents a method to calculate the forming shrinkage needed of line heating forming process related to the unfolding plane. For the Saddle Plate, it can calculate the shrinkage at each grid point by the lack of the forming length and the unfolding length. For the Sail Plate, it can calculate the shrinkage by the cracks at each grid point. This paper draws the Forming Shrinkage Array by a certain scale to express the forming shrinkage by line heating process at each grid point should be achieved visually.By the Improved Frame-Curvature Unfolding Method, the paper unfolds some hull plates offered by some shipyard, and calculates forming shrinkage of the unfolding plane. By analyzing the result, it fully meets the requirements. The method can be used to production practice.Based on the Improved Frame-Curvature Unfolding Method and the method of calculating shrinkage, the author developed the Complex-Curved Hull Plate Unfolding Software. The software can unfold the complex curved hull plate, and obtain the grid point of unfolding plane and its forming shrinkage. It can also draw the picture of the unfolding plane and the Forming Shrinkage Array by calling AutoCAD. |
