A Forming Evaluation Method of Water-fired Bending Surface Based on Gaussian Curvature Difference Ratio

Abstract

The invention discloses a line heating curved surface forming evaluation method based on a Gaussian curvature difference ratio. The method is mainly applied to the overall bending forming process for a ship hull plate based on a line heating technology in the shipbuilding industry. The method mainly comprises the following steps: (1) randomly selecting points on a forming plate and finding points corresponding to the points on a standard plate; (2) working out the Gaussian curvatures of the points on the forming plate and the corresponding points on the standard plate respectively; (3) calculating the Gaussian curvature difference ratio of the randomly selected points, and if the Gaussian curvature difference ratio is smaller than a set threshold value, achieving good forming effect of the points and successfully matching the points on the forming plate with the points on the standard plate; (4) calculating the proportion of the successfully matched points on the forming plate in all points to finish the curved surface forming evaluation. According to the method, starting with Gaussian curvatures of points on a formed curved surface, the D-values of the Gaussian curvatures of the points on the formed curved surface and the corresponding points on the standard plate are compared, so that the line heating forming effect can be effectively judged and evaluated; in addition, the method can be used for evaluating the line heating forming effect and judging the similarity of general curved surfaces.

Description

technical field [0001] The present invention relates to the technical field of forming evaluation of large and complex hull plates, in particular to a water-fire bending surface forming evaluation method based on Gaussian curvature difference ratio, which is mainly used in shipbuilding industry based on vector slope difference ratio for forming of hull outer plate surface testing and evaluation. Background technique [0002] Water-fire bending, also known as line heating or line heat of forming, is a forming process that utilizes the local thermoelastic-plastic deformation of the metal plate after being locally heated and cooled at a high temperature to achieve overall bending. The water-fire bending plate forming process originated in Japan in the 1950s and 1960s. Due to the advantages of fast processing, flexible operation, no need for other equipment, and suitable for forming complex shapes, it has been rapidly and widely used in shipyards around the world. It has become...

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Problems solved by technology

Although this method has certain advantages in on-the-spot judgment, it has no relevant theoretical basis, no quantitative standard, and insufficient stability, which is not conducive to generalization, nor is it conducive to inheritance and large-scale development.

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