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DCONSTR |
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DCONSTR |
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»Click here to display Table of Contents«
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DCONSTR |
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DCONSTR |
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Bulk Data Entry
DCONSTR – Design Constraints
Description
Defines design constraint upper and lower bounds where response is defined by DRESP1, DRESP2, and DRESP3 cards.
Format
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DCONSTR |
DCID |
RID |
LBOUND/ |
UBOUND/ |
LFREQ/ |
UFREQ |
PROB |
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(2) |
(3) |
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DRESP1 |
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TOPN |
DISP |
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4668 |
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Field |
Contents |
DCID |
Design constraint identification number. (Integer > 0) |
RID |
DRESP1, DRESP2, or DRESP3 identification number. (Integer > 0) |
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 (see comments). (Real, Integer, or blank) |
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 (see comments). (Real, Integer, or blank) |
LFREQ/LOCBUCK |
LFREQ: Lower bound on a loading frequency range. Default = 0.0 (Real > 0.0) LOCBUCK: Lower bound of a local buckling eigenvalue response (Comment 8). No Default (Real > 0.0) |
UFREQ |
Upper bound on a loading frequency range. Default = 1.0E+20 (Real > LFREQ) |
PROB |
Probability value for Reliability-based Design Optimization runs. (50.0 < Real < 100.0) |
| 1. | The DCONSTR DCID is selected in the Subcase Information section by the DESSUB or DESGLB cards and/or referenced by the DCONADD card. |
| 2. | For any DCID, the associated RID can be referenced only once. |
| 3. | If LBOUND or UBOUND are blank, the corresponding constraint will not be generated for the bound (lower, upper, or both). |
| 4. | 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. |
| 5. | LFREQ, UFREQ apply only to response types related to a frequency response subcase (DRESPi, RTYPE = FRDISP, FRVELO, FRACCL, FRSTRS, FRSTRN, FRFORC, and FRERP). 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. |
| 6. | LTID, UTID identify a loading frequency dependent tabular input using TABLEDi. They are applied analogous to LFREQ, UFREQ detailed in comment 5. |
| 7. | Equality constraints can be applied by setting LBOUND and UBOUND equal to the same value (which is the value of the constraint that the response is required to attain). The LBOUND/LTID and UBOUND/UTID fields should not reference Table ID’s for equality constraints. Equality Constraints are only supported for Size, Shape Optimizations and the SQP or BIGOPT optimization algorithms should be used (see DOPTPRM,OPTMETH and Optimization Algorithms). |
| 8. | The local buckling zone can be defined using DOPTPRM, BKLOCAL2 and DOPTPRM, BKLOCAL1. The LOCBUCK field can be used to specify the lower bound of the local buckling eigenvalue response. If the specified response is determined to be a local buckling mode, the LOCBUCK lower bound is utilized, otherwise, the LBOUND lower bound value is used for the response. |
| 9. | This card is represented as an optimizationconstraint in HyperMesh. |
See Also:
