Abstract: This present invention relates to a method of creating a shell element analytical model for two-dimensional analysis from a three-dimensional solid analytical model by a finite element method on the basis of three-dimensional geometric data designed by three-dimensional CAD. An analytical model conversion method of this invention is an analytical model conversion method of converting a three-dimensional analytical model into a two-dimensional analytical model, which includes generating tetrahedral solid elements for an input three-dimensional geometric model, and connecting the intermediate nodes of sides that extend in the direction of plate thickness in each solid element to generate a triangular or rectangular shell element.

Abstract: This invention provides an optical component free from weld formation in its optical surface and having an excellent optical performance, a method of molding an optical component, and a mold for molding an optical component. For this purpose, an optical component as a plastic molded product having an optical function, is formed with a molding surface with a shape of a curved surface, and a flange portion between the molding surface and a gate portion. At least part of a surface constituting the flange portion is molded by injecting a molten resin along a wall surface that forms an angular difference of 15.degree. or less which is substantially equal to a tangential angle to the curvature of the curved surface of the molding surface, which is near the flange portion.