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doc:user:conditions:rotations

Prescribed Rotations

Loading in cylindrical frame : imposed rotations - radial displacements (around a moving axis)

Displacements and rotations imposed with respect to an axis are extensions of imposed displacements (translations) and are used to rotate/move a set of nodes around an axis, which can be moving. As for displacements, this is done with LoadingSet. The motion of the axis is defined in the LoadingSet.

Translation of rotation axis

(axis defined by points p1 and p2):

loadingset.define(p1, Field1D(TX,RE), dx1, fctX1)
loadingset.define(p1, Field1D(TY,RE), dy1, fctY1)
loadingset.define(p1, Field1D(TZ,RE), dz1, fctZ1)
loadingset.define(p2, Field1D(TX,RE), dx2, fctX2)
loadingset.define(p2, Field1D(TY,RE), dy2, fctY2)
loadingset.define(p2, Field1D(TZ,RE), dz2, fctZ2)
p1 reference of the origin of the axis
dx1, dy1, dz1 displacements of p1
fctX1, fctY1, fctZ1 Functions y=f(t) of the displacement of p1
p2 reference of the end of the axis
dx2, dy2, dz2 displacements of p1
fctX2, fctY2, fctZ2 Functions y=f(t) of the displacement of p2

Case #1: Radial displacement imposed with respect to the axis

loadingset.defineRad(gObject, Field1D(TX,RE), p1, p2, ampl, fct)
gObject Geometric entity
field name of the variable which is concerned by the motion
ampl amplitude
fct Functions y=f(t) (temporal dependency)
p1 reference of the origin of the axis
p2 reference of the end of the axis

Case #2: Rotation imposed around the axis

loadingset.defineRot(gObject, field, p1, p2, option, ampl, fct)
gObject Geometric entity
field name of the variable which is concerned by the motion (only Field3D(TXTYTZ,RE) allowed)
ampl amplitude
fct Functions y=f(t) (can depend on time and position)
p1 reference of the origin of the axis
p2 reference of the end of the axis
option = False : the boundary condition is a given angle, in degrees
= True : the boundary condition is a given angular speed, in degrees/second

Case #3: 2 successives Rotations imposed around 2 axis

loadingset.defineRot2(gObject, field, axe1, ampl1, fct1, axe2, ampl2, fct2, option)
gObject Geometric entity
field name of the variable which is concerned by the motion (only Field3D(TXTYTZ,RE) allowed)
axe1 first axe of rotation (mtGeoAxe object)
ampl1 amplitude first rotation
fct1 Functions y=f(t) of the first rotation (can only depend on time)
axe1 second axe of rotation (mtGeoAxe object)
ampl1 amplitude second rotation
fct1 Functions y=f(t) of the second rotation (can only depend on time)
option = False : the boundary condition is a given angle, in degrees
= True : the boundary condition is a given angular speed, in degrees/second
doc/user/conditions/rotations.txt · Last modified: 2017/07/26 17:41 by papeleux