PBUSH

Generalized Spring and Damper Property

Description: Defines the nominal property values for a generalized spring and damper structural element.

Format:

Example:

Field Definition Type Default
PID Property identification number. Integer > 0 Required
K Symbol indicating that the next 1 to 6 fields are stiffness values. Character Required
Ki Nominal stiffness values in directions 1 through 6. See Remark 2 and 3. Real 0.0
B Symbol indicating that the next 1 to 6 fields are force per unit velocity damping. Character
Bi Nominal damping coefficient in units of force per unit velocity. See Remark 3. Real 0.0
GE Symbol indicating that the next field is the structural damping constant. Character
GE1 Nominal structural element damping coefficient. Real 0.0
RCV Symbol indicating that the next 1 to 4 fields are stress coefficients. Character
SA Stress recovery coefficient in the translational component direction 1 through 3. Real 1.0
ST Stress recovery coefficient in the rotational component direction 4 through 6. Real 1.0
EA Strain recovery coefficient in the translational component direction 1 through 3. Real 1.0
ET Strain recovery coefficient in the rotational component direction 4 through 6. Real 1.0

Remarks:

  1. Ki, Bi, or GE1 may be made frequency dependent for modal frequency response analysis and K may be made force dependent for nonlinear analysis by use of the PBUSHT entry.
  2. For modal frequency response the normal modes are computed using the nominal Ki values. The frequency dependent values are used at every excitation frequency.
  3. If PARAM, W4 is not specified, GE1 is ignored in transient response analysis. (See Section 5, Parameters, for more information on W4.)
  4. The element stresses are computed by multiplying the stress coefficients with the recovered element forces.
  5. The element strains are computed by multiplying the strain coefficients with the recovered element displacements.
  6. The K, B, GE or RCV options may be specified in any order.