# DVPREL1

Bulk Data Entry Relates Design Variables to Analysis Model Properties

Linearly relates a design variable to an analysis model property using the equation:(1)
${P}_{i}=C0+\sum _{i}{\mathit{COEF}}_{i}*{\mathit{DDVI}}_{i}$

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DVPREL1 ID TYPE PID PNAME/

FID

C0
DVID1 COEF1 DVID2 COEF2 etc.

## Example 1

To relate the thickness value on a PSHELL card (field 4) to Design Variable 5.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DVPREL1 88 PSHELL 1 4     0.0
5 1.
DESVAR 5 DV1 5.00 1.50 9.90

## Example 2

This example is the same as example 1 (above), except that it defines PNAME.
(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
DVPREL1 88 PSHELL 1 T     0.0
5 1.
DESVAR 5 DV1 5.00 1.50 9.90

## Definition

Field Contents SI Unit Example
ID Relationship identification number. ID must be unique with respect to other DVPREL1 cards.

No default (Integer > 0)

TYPE Property type to be related (see DVPREL - Types).

No default (Character)

PID Property identification number. When PTYPE is PCOMPG, G# may be used where # is the GPLYID. When PTYPE is PCOMPP, P# may be used where # is the PLY ID. 2

No default (Integer > 0)

PNAME/FID Property name, such as "A" or "T" (as in the documentation of the property cards), or field number in property card (see Table 1). For the PSHELL property 12I/T3, only the field number (6) is allowed. For PBARL and PBEAML only property names are allowed, as different sections use different fields.

No default (Character or Integer > 0)

C0 Constant in relationship equation.

Default = 0.0 (Real)

DVIDi DESVAR ID.

No default (Integer > 0)

COEFi Coefficient in relationship equation.

Default = 1.0 (Real)

1. TYPE cannot be PSOLID.
• the DDVAL field of a DESVAR Bulk Data Entry
• the SPTID field of a RSPINR Bulk Data Entry
2. When TYPE is PCOMPG, either global plies or property specific plies may be selected.

To select property specific plies, the format is similar to that used for other property types where the property identification number of the PCOMPG is entered in the PID field and then either PNAME or FID is used to identify the value to be related. In this scenario, only the property with an ID given in the PID field is affected.

To select global plies, G# is entered in the PID field where, # is the GPLYID of a global ply. In this instance, FID is not applicable, so T or THETA is used in the PNAME field to relate either the thickness or orientation, respectively. In this scenario, all plies that use the given GPLYID are affected.

When TYPE is PCOMPP, P# is entered in the PID field where # is the ID of a PLY entity. In this instance, FID is not applicable, so T or THETA is used in the PNAME field to relate either the thickness or orientation, respectively.

3. PBEAML definitions with more than one section definition may not be referenced by a DVPREL1.
4. Properties of PBARL/PBEAML have to be controlled through DIMs (cannot be controlled directly), with the exception of NSM.
5. When TYPE is PBARL or PBEAML, users should pay close attention to the variable ranges to avoid invalid dimensions. For example, the inner radius of a tube cross-section cannot exceed the outer radius. It is necessary to prevent combinations of dimensions from taking on values that are physically meaningless. Some constraints are applied automatically on section dimensions. The table below summarizes these constraints. Constraints are satisfied when they are < 0.0.
Table 1.
Section Type Constraint
TUBE DIM2 - DIM1
I DIM4 - DIM2
DIM4 - DIM3
DIM5 + DIM6 - DIM1
CHAN 2 * DIM4 - DIM2
DIM3 - DIM1
T DIM3 - DIM2
DIM4 - DIM1
BOX DIM4 - DIM1
DIM3 - DIM2
CROSS DIM4 - DIM3
H DIM4 - DIM3
T1 DIM4 - DIM1
I1 DIM3 - DIM4
CHAN1 DIM3 - DIM4
Z DIM3 - DIM4
CHAN2 DIM2 - DIM3
2 • DIM1 - DIM4
T2 DIM4 - DIM1
DIM3 - DIM2
BOX1 DIM4 + DIM3 - DIM2
DIM5 + DIM6 - DIM1
HEXA 2 * DIM1 - DIM2
HAT 2 * DIM2 - DIM1
2 * DIM2 - DIM3
L DIM3 - DIM2
DIM4 - DIM1
HAT1 DIM3 - DIM1
2 * DIM4 - DIM2
2 * DIM4 + DIM5 - DIM2
6. In the PCOMP property, the damping coefficient, GE is a designable value and can be referenced in the PNAME/FID field.
7. This card is represented as an optimization design variable in HyperMesh.