PBUSH1D

Format

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)
PBUSH1D	`PID`	`K`	`B`	`M`
	`SPRING`	`TYPE`	`IDT`	`IDC`	`IDTDU`	`IDCDU`
	`DAMPER`	`TYPE`	`IDT`	`IDC`	`IDTDV`	`IDCDV`
	`GENER`		`IDT`	`IDC`	`IDTDU`	`IDCDU`	`IDTDV`	`IDCDV`

Example 1

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
PBUSH1D	35	4.35	0.5

Example 2

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
PBUSH1D	35	4.35
	`SPRING`	TABLE	43

Definitions

Field	Contents	SI Unit Example
`PID`	Property identification number. No default (Integer > 0)
`K`	Stiffness. Default = 0.0 (Real > 0)
`B`	Viscous damping. Default = 0.0 (Real > 0)
`M`	Total mass. Default = 0.0 (Real > 0)
`SPRING`	String indicating that a function defining the spring characteristics follows. Tension U > 0 Compression U < 0 Where, U = U(GB) - U(GA) in CBUSH1D element coordinate system: GA/GB are grid points on CBUSH1D
`DAMPER`	String specifying that the next 5 fields define a nonlinear viscous element in terms of a force versus velocity relationship. (Character)
`GENER`	String specifying that the next 7 fields define a general nonlinear elastic spring and viscous damper element in terms of a force versus displacement and velocity relationship. (Character). For this element, the relationship can only be defined with `TYPE`=EQUAT
`TYPE`	String indicating the type of definition. EQUAT The following fields are identification numbers of DEQATN entries. TABLE The following field is an identification number of a TABLEDi entry. For `GENER`, `TYPE` = blank or EQUAT is allowed. (Character)
`IDT`	Identification number of a DEQATN entry for tension if `TYPE`=EQUAT. Identification number of a TABLEDi entry for tension and compression if `TYPE`=TABLE. No default (Integer > 0)
`IDC`	Identification number of a DEQATN entry for compression if `TYPE`=EQUAT. Is ignored for `TYPE`=TABLE. Default = `IDT` (Integer)
`IDTDU`	Identification number of a DEQATN entry for tension if `TYPE`=EQUAT. The DEQATN entry defines the derivative of the force `F` with respect to the displacement, u for tension u > 0. For `SPRING` and `GENER` only, Required if `TYPE`=EQUAT. No default (Integer)
`IDCDU`	Identification number of a DEQATN entry for compression if `TYPE`=EQUAT. The DEQATN entry defines the derivative of the force `F` with respect to the displacement u, for compression u < 0. For `SPRING` and `GENER` only. Default = `IDTDU` (Integer)
`IDTDV`	Identification number of a DEQATN entry for tension if `TYPE`=EQUAT. The DEQATN entry defines the derivative of the force `F` with respect to the velocity v, for tension v > 0. For `DAMPER` and `GENER` only, Required if `TYPE`=EQUAT. No default (Integer)
`IDCDV`	Identification number of a DEQATN entry for compression if `TYPE`=EQUAT. The DEQATN entry defines the derivative of the force `F` with respect to the velocity v, for compression v < 0. For `DAMPER` and `GENER` only. Default = `IDTDV` (Integer)

Comments

Either the stiffness K, or the damping B, or the mass M must be specified. B and M are ignored in static subcases.
The SPRING continuation line is used in nonlinear analysis solution sequences only. The table input supersedes the stiffness K.
PBUSH1D may only be referenced by CBUSH1D elements.
PBUSH1D is supported with linear static, nonlinear static, as well as nonlinear transient analysis types, for small and large displacement cases.
In all linear subcases, as well as small displacement nonlinear analysis (ANALYSIS=NLSTAT) subcases, PBUSH1D and CBUSH1D are converted internally to the equivalent PBUSH (with PBUSHT, if necessary) and CBUSH.
The parameters defined on the continuation entries are used in nonlinear solution sequences only.
The linear K and C are used in all solution sequences unless parameters on continuation entries are defined and a nonlinear solution sequence is used. Then, the parameters K and C are used for initial values in the first iteration of the first load step and the parameters from continuation entries overwrite the linear parameters thereafter. When SPRING or GENER are specified, K is overwritten. When DAMPER or GENER is specified, C is overwritten.
If more than one continuation entry is defined, then the forces of SPRING, etc. are superposed. Multiple continuation entries of the same kind are not allowed.
For TYPE=TABLE, values on the TABLEDi entry are for tension and compression. If table values are provided only for positive values arguments, then it is assumed that the function defined by the table is an odd function regarding zero.
For TYPE=EQUAT, the equations for tension and compression can be different. If the identification numbers for compression are left blank, it is assumed that the same equation applied to both tension and compression.
This card is represented as a property in HyperMesh.