# PELAS

Bulk Data Entry Used to define the stiffness and stress coefficient of a scalar elastic element (spring) by means of the CELAS1 or CELAS3 entry.

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PELAS PID K GE S PID K GE S

## Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PELAS 7 4.29   7.92 27 2.17

## Definitions

Field Contents SI Unit Example
PID Unique scalar elastic property identification.
Integer
Specifies an identification number for this property.
<String>
Specifies a user-defined string label for this property. 1

No default (Integer > 0 or <String>)

K Elastic property value.

No default (Real)

GE Damping coefficient. To obtain the damping coefficient GE, multiply the critical damping ratio, $C/{C}_{0}$ by 2.

GE is ignored in transient analysis, if PARAM, W4 is not specified.

Default = 0.0 (Real)

S Stress coefficient.

Default = 0.0 (Real)

1. String based labels allow for easier visual identification of properties, including when being referenced by other cards. (For example, the PID field of elements). For more details, refer to String Label Based Input File in the Bulk Data Input File.
2. Be careful using negative spring values.
3. One or two elastic spring properties may be defined on a single entry.
4. The element force of a spring is calculated from the equation:(1)
$f=k*\left({u}_{1}-{u}_{2}\right)$
Where,
$k$
Stiffness coefficient for the scalar element.
${u}_{1}$
Displacement of the first degree-of-freedom listed on the CELAS1 and CELAS3 entries.
${u}_{2}$
Displacement of the second degree-of-freedom listed on the CELAS1 and CELAS3 entries.
Element stresses are calculated from the equation: (2)
$s=S*f$
Where, $S$ is the stress coefficient as defined above.
5. This card is represented as a property in HyperMesh.