SPLINE1

Bulk Data Entry Defines a surface spline for interpolating motion and forces for aeroelastic problems on aerodynamic geometries defined by regular arrays of aerodynamic points.

Format

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
SPLINE1 EID CAERO BOX1 BOX2 SETG DZ METH USAGE

Example

(1) (2) (3) (4) (5) (6) (7) (8) (9) (10)
SPLINE1 56 33 12 13 11 0.0

Definitions

Field Contents SI Unit Example
EID Unique spline identification number.

(Integer > 0)

 
CAERO Aero-element (CAEROi entry ID) that defines the plane of the spline.

(Integer > 0)

 
BOX1, BOX2 First and last box with motions that are interpolated using this spline. 1

(Integer > 0; BOX2 > BOX1)

 
SETG Refers to the SETi entry that lists the structural grid points to which the spline is attached.

(Integer > 0)

 
DZ Linear attachment flexibility.

Default = 0.0 (Real ≥ 0.0)

 
METH Spline fit method.
IPS (Default)
Harder-Desmarais Infinite Plate Spline.
TPS
Thin Plate Spline.
 
USAGE Spline usage flag. 3
BOTH (Default)
For both force and displacement transformations.
 

Comments

  1. The interpolated points (k-set) is defined by aero boxes. Figure 1 shows the cells for which u k MathType@MTEF@5@5@+= feaagKart1ev2aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq=Jc9 vqaqpepm0xbba9pwe9Q8fs0=yqaqpepae9pg0FirpepeKkFr0xfr=x fr=xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyDamaaBa aaleaacaWGRbaabeaaaaa@380D@ is interpolated, if BOX1 = 326 and BOX2 = 333.


    Figure 1. SPLINE1 Entry Example
  2. The attachment flexibility (units of area) is used for smoothing the interpolation. If DZ = 0.0, the spline passes through all deflected grid points. If DZ is much greater than the spline area, a least squares plane fit is applied. Intermediate values provide smoothing.
  3. The USAGE field allows you to specify that the particular spline interpolant defined in this entry is to be used for both the force transformation and the displacement transformation. Currently, only the BOTH option is supported for the USAGE field.
  4. The SPLINE1 EID must be unique with respect to all SPLINEi entries.