FORMING LIMIT CURVE
The functions in this menu are used to create, read, and display the FLD curve of the materials. The dialog box is shown in Figure 9.9.6. These options are similar to those described in Section 11.13.
Figure 9.9.6 Forming Limit Curve dialog box
CREATE CURVE
This option enables the user to create a FLC Curve based on the Keeler’s empirical formula. There are two methods to define the FLD0. One is by calculating the FLD0 through the thickness (t) and hardening parameter (n), while the other one is by inputting the FLD0 directly. Figure 9.9.7 illustrates the CREATE FLC dialog box.
Figure 9.9.7 Create FLC dialog box
CURVE NUMBER – Enables the user to define the curve ID for the current FLC curve.
CURVE NAME - Enables the user to define the curve name for the current FLD curve.
THICKNESS (MM) - Enables the user to define the thickness required by the Keeler’s empirical formula for calculating the FLD0. The unit of the thickness is in millimeter.
HARDENING EXPONENT (N) - Enables the user to define the hardening exponent (n) required by the Keeler’s empirical formula for calculating the FLD0.
BY FLD0 – This function enables the user to manually input the user-defined FLD0. The default FLD0 is calculated by the Keeler’s empirical formula. However, the user can edit the value. Usually, the FLD0 and FLC are expressed in engineering strain. The true strain FLD0 and FLC is also supported.
NOTE: There are three different curve formats that are supported by eta/DYNAFORM; These curve formats can be read into an eta/DYNAFORM database.
FORMAT 1: FEMB read in format
$ THIS IS THE FEMB FORMAT LOAD CURVE
$ FEMB LOAD CURVE (TITLE LINE HAVE BEEN EXIST)
$CURVE, CURVE ID, TYPE, CURVE NAME (A9, I9, I9, 1X, A8)
CURVE 9 0 CURVE9
$CURVE DATA (X, Y) (F9.0, F9.0)
0.0000E+000.1349E+03
0.900E-09.2018E+03
0.3000E-09.269E+03
0.9000E-09.3017E+03
0.7000E-09.3282E+03
0.9000E-09.3494E+03
0.190E+000.3674E+03
0.1300E+000.3831E+03
0.1900E+000.3970E+03
0.1700E+000.4097E+03
0.1900E+000.4212E+03
0.290E+000.43199E+03
0.2300E+000.4418E+03
0.2900E+000.4911E+03
0.2700E+000.4999E+03
0.2900E+000.4682E+03
0.9990E+09.4722E+02
END
FORMAT 2: FEMB write out format (can be read in also)
1 (CURVE NUMBER, I9)
27 'fld' 90 (num. of points, 'curve name', curve id) (4x, i,'a8', i4)
-4.94296E-01 9.00160E-01
-4.46287E-01 8.92777E-01
-4.00478E-01 8.06437E-01
-3.96679E-01 7.61400E-01
-3.14711E-01 7.17994E-01
-2.74437E-01 6.76406E-01
-2.39722E-01 6.37089E-01
-1.98491E-01 6.00334E-01
-1.62919E-01 9.66903E-01
-1.27833E-01 9.39946E-01
-9.43970E-02 9.09004E-01
-6.18794E-02 4.86003E-01
-3.04992E-02 4.67236E-01
0.00000E+00 4.92994E-01
2.99988E-02 4.71172E-01
9.82689E-02 4.86212E-01
8.61777E-02 4.98662E-01
1.13329E-01 9.08994E-01
1.39762E-01 9.17989E-01
1.69914E-01 9.24738E-01
1.90620E-01 9.30703E-01
2.19111E-01 9.39683E-01
2.39017E-01 9.39843E-01
2.62364E-01 9.43322E-01
2.89179E-01 9.46232E-01
3.07489E-01 9.48669E-01
3.29304E-01 9.90709E-01
FORMAT 3: (DYNA format)
*KEYWORD (must)
*DEFINE_CURVE
$CURVENAME ABC
$ LCID SIDR SCLA SCLO OFFA OFFO
200 0
$ A1 O1
.000000000E+00 .000000000E+00
.476209790E+00 .770189471E+02
.992419979E+00 .122399673E+03
.142862940E+01 .149092189E+03
.190483916E+01 .164766199E+03
.238948920E+01 .174017044E+03
.289729880E+01 .179463074E+03
.333346844E+01 .182669189E+03
.380967832E+01 .184996629E+03
.428988820E+01 .189667770E+03
.476209784E+01 .186321899E+03
*END
(Here the *END is optional)