NOLIN2

Bulk Data Entry Defines nonlinear transient forcing functions of the form.

Pi(t)=S⋅Xj(t)⋅Xk(t)

Where, Xj(t) and Xk(t) 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

  1. Nonlinear loads must be selected by the Subcase Information data selector NONLINEAR.
  2. Nonlinear loads may not be referenced on a DLOAD entry.
  3. All degrees-of-freedom referenced on NOLIN2 entries must be members of the solution set.
  4. GI-CI, GJ-CJ and GK-CK may be the same degree-of-freedom.
  5. Nonlinear loads may be a function of displacement (X=˙u) or velocity (X=˙u) . 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:
    u ˙ t = u t − u t − 1 Δ t
    Where,
    Δ t
    Time step interval.
    u t − 1 MathType@MTEF@5@5@+= feaagKart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyDamaaBa aaleaacaWG0bGaeyOeI0IaaGymaaqabaaaaa@39BD@
    Displacement of GJ-CJ or GK-CK for the previous time step.
  6. 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.