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--- doc:user:conditions:rotations [2016/03/30 15:23] – external edit 127.0.0.1
+++ doc:user:conditions:rotations [2022/04/28 17:17] (current) – [Case #3: 2 successive Rotations imposed around 2 axes] boman
@@ Line 1: / Line 1: @@
 ====== Prescribed Rotations ======
-===== Loading in cylindrical frame : imposed rotations - radial displacements (around a moving axis) =====
+===== Loading in cylindrical frame : prescribed 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''.
+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 in motion too. As for displacements, this is done with ''LoadingSet''. The motion of the axis is also defined in the ''LoadingSet''.
-===== Translation of rotation axis =====
+===== Translation of the axis =====
-(axis defined by points ''p1'' and ''p2''):
+If the axis is defined by points ''p1'' and ''p2'', its motion can be defined by commands similar to the following ones:
   loadingset.define(p1, Field1D(TX,RE), dx1, fctX1)
@@ Line 16: / Line 16: @@
   loadingset.define(p2, Field1D(TZ,RE), dz2, fctZ2)
-| ''p1'' | reference of the origin of the axis |
+| ''p1''                          | reference [[doc:user:geometry:user:points|Point]] at the origin of the axis |
-| ''dx1'', ''dy1'', ''dz1'' | displacements of p1 |
+| ''dx1'', ''dy1'', ''dz1''       | amplitudes of the x,y,z displacements of point p1 |
-| ''fctX1'', ''fctY1'', ''fctZ1'' | [[doc:user:general:fonctions]] of the displacement of p1 |
+| ''fctX1'', ''fctY1'', ''fctZ1'' | x,y,z displacement [[doc:user:general:fonctions]] of p1 |
-| ''p2'' | reference of the end of the axis |
+| ''p2''                          | reference [[doc:user:geometry:user:points|Point]] at the end of the axis |
-| ''dx2'', ''dy2'', ''dz2'' | displacements of p1  |
+| ''dx2'', ''dy2'', ''dz2''       | amplitudes of the x,y,z displacements of point p2  |
-| ''fctX2'', ''fctY2'', ''fctZ2'' | [[doc:user:general:fonctions]] of the displacement of p2 |
+| ''fctX2'', ''fctY2'', ''fctZ2'' | x,y,z displacement [[doc:user:general:fonctions]] of p2 |
 ===== Case #1: Radial displacement imposed with respect to the axis =====
-  loadingset.defineRad(gObject, field, p1, p2, ampl, fct)
+  loadingset.defineRad(gObject, Field1D(TX,RE), p1, p2, ampl, fct)
 | ''gObject'' | Geometric entity |
-| ''field'' | name of the variable which is concerned by the motion |
+| ''field''   | name of the variable which is concerned by the motion |
-| ''ampl'' | amplitude |
+| ''ampl''    | amplitude |
-| ''fct'' | [[doc:user:general:fonctions]] (temporal dependency)|
+| ''fct''     | [[doc:user:general:fonctions]] (time dependence)   |
-| ''p1'' | reference of the origin of the axis|
+| ''p1''      | reference [[doc:user:geometry:user:points|Point]] at the origin of the axis      |
-| ''p2'' | reference of the end of the axis|
+| ''p2''      | reference [[doc:user:geometry:user:points|Point]] at the end of the axis         |
@@ Line 46: / Line 41: @@
 | ''gObject'' | Geometric entity |
-| ''field''  | name of the variable which is concerned by the motion |
+| ''field''   | name of the variable which is concerned by the motion (only ''Field3D(TXTYTZ,RE)'' is allowed) |
-| ''ampl''   | amplitude |
+| ''ampl''    | amplitude |
-| ''fct''    | [[doc:user:general:fonctions]] (can depend on time and position) |
+| ''fct''     | [[doc:user:general:fonctions]] (can depend on time and position) |
-| ''p1''     | reference of the origin of the axis|
+| ''p1''      | reference [[doc:user:geometry:user:points|Point]] at the origin of the axis  |
-| ''p2''     | reference of the end of the axis|
+| ''p2''      | reference [[doc:user:geometry:user:points|Point]] at 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 |
+| ''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 successive Rotations imposed around 2 axes =====
+  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)'' is allowed) |
+| ''axe1''    | first axis of rotation (''Axe'' object). |
+| ''ampl1''   | amplitude of the first rotation |
+| ''fct1''    | [[doc:user:general:fonctions]] of the first rotation (can only depend on time) |
+| ''axe2''    | second axis of rotation (''Axe'' object). The motion of this axis drives the global translation of the object |
+| ''ampl2''   | amplitude of the second rotation |
+| ''fct2''    | [[doc:user:general:fonctions]] 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 |
+The geometry is transformed in the following way:
+  * the rotation around the FIRST axis is applied to the object,
+  * then, the object is translated according to the SECOND axis motion,
+  * finally, the geometry is rotated around the SECOND axis.
+In other words, it means that the second axis of ''defineRot2'' behaves as the single axis of ''defineRot''.