| 摘要 |
PROBLEM TO BE SOLVED: To provide an evaluation test method for obtaining the flange shape design guideline of actual parts for automobile having a hat-shaped section or the result of stretch flange formability which is directly utilized for establishing the design limit. SOLUTION: In the evaluation test method for evaluating the stretch flange formability of a metal sheet in which a metallic blank having corners cut in a V-shape on two ridges opposite to each other is press-formed to obtain a formed product of a hat-shaped section by using a punch and a die, the press-forming is repeatedly performed by changing at least one kind of the blank shape variables of the radii of curvature R1, R2 [mm] of the first and second corners of the blank, the first and second opening anglesθ1,θ2 [°], the first and second flange heights H1, H2 [mm], and the width W [mm] of the blank, the evaluation map of the blank shape variables and the stretch flange formability is prepared, and the forming limit is obtained thereby. COPYRIGHT: (C)2009,JPO&INPIT
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