# PBUSHFX

Bulk Data Entry Defines the various nominal property values for a generalized spring-damper-mass structural element. This property is not affected by translational and rotational stiffness limits specified using PARAM, BUSHSTIF.

## Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PBUSHFX PID K K1 K2 K3 K4 K5 K6
B B1 B2 B3 B4 B5 B6
GE GE1 GE2 GE3 GE4 GE5 GE6
M M1 M2 M3 M4 M5 M6

## Example 1

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PBUSHFX 35 K 4.35 2.4 RIGID     3.1
GE 0.02

## Example 2

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
PBUSHFX 35 B 4.35
M 1.2   7.1

## Definitions

Field Contents SI Unit Example
PID Property identification number.

No default (Integer > 0)

K Flag indicating that the next 1 to 6 fields are stiffness values.

No default (Character)

Ki Nominal stiffness values in directions 1 through 6. 3 5
RIGID
A very high relative stiffness (relative to the surrounding structure) is selected for that degree-of-freedom simulating a rigid connection.

Default = 0.0 (Real or RIGID)

B Flag indicating that the next 1 to 6 fields are force-per-velocity damping.

No default (Character)

Bi Nominal damping coefficients in directions 1 through 6 in units of force per unit velocity.

Default = 0.0 (Real)

GE Flag indicating that the next 1 to 6 fields are the structural damping constants.

No default (Character)

GEi Nominal structural damping constants in directions 1 through 6.

GEi is ignored in transient analysis, if PARAM, W4 is not specified. 3 5

Default = 0.0 (Real)

M Flag indicating that the next 1 to 6 fields are directional masses.
Mi Nominal mass values in directions 1 through 6. The Mi fields do not contribute to mass and inertia properties. Their contributions to gravity and/or centrifugal loading are also not included.

Default = 0.0 (Real)

4. To obtain the damping coefficient GE, multiply the critical damping ratio $C/{C}_{0}$ by 2.0.