公开(公告)号：US20150294043A1

公开(公告)日：2015-10-15

申请号：US14436236

申请日：2013-10-10

Applicant: JFE STEEL CORPORATION

Inventor： Osamu SONOBE ,  Akinobu ISHIWATARI ,  Masaki URABE ,  Hirotaka KANO ,  Jiro HIRAMOTO

IPC: G06F17/50 ,  G06F17/10 ,  G01L5/00

CPC classification number: G06F17/5009 ,  B21D19/00 ,  B21D22/02 ,  B21D53/88 ,  G01L5/00 ,  G01M99/007 ,  G01N3/28 ,  G01N2203/0075 ,  G01N2203/0254 ,  G01N2203/027 ,  G06F17/10

Abstract: A method for specifying stretch flange limit strain includes specifying stretch flange limit strain so as to satisfy a relation in the following formula by using: strain gradient in an inward direction directed from an end portion of a metal sheet at a time a press load is applied; and strain gradient in a sheet thickness direction of the metal sheet intersecting the loading direction: εθlim=A[a·Δεθ/Δr+b·Δεθ/Δt]+c where εθlim represents the stretch flange limit strain (tangential direction of the sheet edge), Δεθ/Δr represents the strain gradient in the inward direction, Δεθ/Δt represents the strain gradient in the sheet thickness direction, A, a, and b represent influence coefficients, and c represents the limit strain at a time the strain gradient is zero.

Abstract translation: 用于规定拉伸凸缘极限应变的方法包括：通过使用：在施加压力载荷时从金属板的端部指向的向内方向上的应变梯度来指定拉伸凸缘极限应变以满足下式的关系： ; 和与加载方向相交的金属板的板厚度方向的应变梯度：＆amp;＆amp;＆nbsp;＆nbsp;＆nbsp;＆nbsp;＆Dgr;＆rdquo;＆Dgr;＆ ] + c其中＆egr;＆thetas; lim表示拉伸法兰极限应变（片材边缘的切线方向），＆Dgr;＆Egr＆amp;＆Thetas; /＆Dgr; r表示向内方向的应变梯度，＆Dgr; ＆Dgr; t表示板厚方向的应变梯度，A，a和b表示影响系数，c表示应变梯度为零时的极限应变。