DCONSTR – Design Constraints
Defines design constraint upper and lower bounds where response is defined by DRESP1, DRESP2, and DRESP3 cards.
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(1) |
(2) |
(3) |
(4) |
(5) |
(6) |
(7) |
(8) |
(9) |
(10) |
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DCONSTR |
DCID |
RID |
LBOUND/ |
UBOUND/ |
LFREQ |
UFREQ |
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(1) |
(2) |
(3) |
(4) |
(5) |
(6) |
(7) |
(8) |
(9) |
(10) |
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DCONSTR |
1 |
9 |
0.5 |
10.0 |
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Associated Cards
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(1) |
(2) |
(3) |
(4) |
(5) |
(6) |
(7) |
(8) |
(9) |
(10) |
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DRESP1 |
9 |
TOPN |
DISP |
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3 |
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4668 |
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Field |
Contents |
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DCID |
Design constraint identification number. (Integer>0) |
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RID |
DRESP1, DRESP2, or DRESP3 identification number. (Integer>0) |
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LBOUND/LTID |
Lower bound on response or table identification number of a TABLEDi entry that specifies the lower bound as function of a loading frequency. (Real, integer, or blank) |
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UBOUND/UTID |
Upper bound on response or table identification number of a TABLEDi entry that specifies the upper bound as function of a loading frequency. (Real, integer, or blank) |
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LFREQ |
Lower bound on a loading frequency range. (Real > 0.0, Default = 0.0) |
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UFREQ |
Upper bound on a loading frequency range. (Real > LFREQ, Default = 1.0E+20) |
The DCONSTR DCID is selected in the subcase information section by the DESSUB or DESGLB cards and/or referenced by the DCONADD card.
For any DCID, the associated RID can be referenced only once.
If LBOUND or UBOUND are blank than no constraint will be generated for the bound.
Constraint bounds of zero should be avoided. Unnecessary bounds should be left blank. For example, lower bounds on von Mises stress should be blank, not zero. If a bound of zero is input, the bound will be changed to 1.0E-7 for lower bounds and –1.0E-7 for upper bounds. This will remove numerical difficulties and cause the constraints to be ignored unless the response is actually very near zero.
LFREQ, UFREQ apply only to response types related to a frequency response subcase (DRESPi, RTYPE = FRDISP, FRVELO, FRACCL, FRSTRE, FRSTRN, and FRFORC). The constraint bounds LBOUND and UBOUND are applied only if the loading frequency falls between LFREQ and UFREQ. If ATTB of DRESP1 specifies a frequency value, LFREQ and UFREQ are ignored.
LTID, UTID identify a loading frequency dependent tabular input using TABLEDi. They are applied analogous to LFREQ, UFREQ detailed in comment 5.
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Guidelines for Bulk Data Entries
Alphabetical List of Bulk Data Entries