NOLIN2
Bulk Data Entry Defines nonlinear transient forcing functions of the form.
Where, and can be either displacement or velocity at points GJ and GK, respectively, in the directions of CJ and CK, respectively.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
NOLIN2 | SID | GI | CI | S | GJ | CJ | GK | CK |
Example
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
NOLIN2 | 14 | 2 | 1 | 2.9 | 2 | 1 | 2 |
Definitions
Field | Contents | SI Unit Example |
---|---|---|
SID | Nonlinear load set
identification number. No default (Integer > 0) |
|
GI | Grid or scalar point
identification number at which nonlinear load is to be
applied. No default (Integer > 0) |
|
CI | Component number for
GI. No default (1 ≤ Integer ≤ 6; blank or 0, if GI is a scalar point) |
|
S | Scale factor. No default(Real) |
|
GJ, GK | Grid or scalar point
identification number. No default (Integer > 0) |
|
CJ, CK | Component number for GJ, GK according to the following table: |
Type | Displacement | Velocity |
---|---|---|
Grid | 1 ≤ Integer ≤ 6 | 11 ≤ Integer ≤ 16 |
Scalar | Blank or 0 | Integer = 10 |
Comments
- Nonlinear loads must be selected by the Subcase Information data selector NONLINEAR.
- Nonlinear loads may not be referenced on a DLOAD entry.
- All degrees-of-freedom referenced on NOLIN2 entries must be members of the solution set.
- GI-CI, GJ-CJ and GK-CK may be the same degree-of-freedom.
- Nonlinear loads may be a function of
displacement
or velocity
. Velocities are denoted by a component number
ten greater than the actual component number; that is the component 11 indicates
velocity in the 1 component direction. The velocity is determined by:
(2) Where,- Time step interval.
- Displacement of GJ-CJ or GK-CK for the previous time step.
- The time step algorithm in transient solution sequences may loose unconditional stability when this load entry is used. In most practical cases, the time step size chosen to reach a certain accuracy is below the stability limit. It is recommended to decrease the time step if results diverge.