Users:Geometry Generation/Design Supports
Dirichlet boundary conditions can be applied to design elements with respect to their parametric coordinates.
Parameter Description
Parameters LOC_COORD | ||
Parameter | Description | Defined for |
---|---|---|
u,v,w = int{0;1} | only valid for = 0 or = 1. 0 denotes the beginning of the knot vector and 1 the end. If nothing is defined, the boundary conditions are applied to the whole patch. | Designelements with respective dimensions. |
DE-BREP int | applies the boundary conditions to the BRepElement. | DesignBRepelement. |
Parameters BC | ||
Parameter | Description | Defined for |
DISP_X DISP_Y DISP_Z DISP_ALL |
blocks the displacement of the corresponding nodes in the respective directions | every element with respective degrees of freedom at the nodes |
DISP_X_NONZERO DISP_Y_NONZERO DISP_Z_NONZERO |
sets the displacement of the corresponding nodes in the respective directions to a value defined by a value (syntax: DISP_X_NONZERO = 0.25, ...) or a NURBS_REF in the Designelement definition. Direct initialization by a value overwrites the other. | every element with respective degrees of freedom at the nodes |
DISP_T1 DISP_T2 DISP_T3 |
blocks the displacement in the respective directions. Is applied as weak boundary condition and summoned over all gauss points. Directions correspond to the base vectors of the element formulation. | ElementNURBS_BRep_EdgeCoupling with ElementSurface_NURBS |
DISP_X_COUPLING DISP_Y_COUPLING DISP_Z_COUPLING |
coupling of the dofs of the corresponding nodes in respective direction. Usable for clamping without blocking the displacements. | every element with respective degrees of freedom at the nodes |
CLAMPED | clampes by blocking the displacements of the first two control points. It is only applicable for open knot vectors. | every NURBS based element |
CLAMPED_X CLAMPED_Y CLAMPED_Z |
clampes by blocking the displacements in the defined directions of the first two control points. Note that, X, Y, Z does not denote the rotation axis. | every NURBS based element |
CLAMPED_TOR | blocks the rotational dof rot_tan. | ElementBeam_3D_NURBS_KLRod,ElementNURBS_BRep_Beam |
CLAMPED_TOR_NONZERO | sets the rotational dof rot_tan to defined value ( by value or NURBS_REF). | ElementBeam_3D_NURBS_KLRod |
ROT_X ROT_Y ROT_Z ROT_ALL |
blocks the rotation of the corresponding nodes around the respective axis. | every element with respective degrees of freedom at the nodes |
ROT_T1 ROT_T2 ROT_T3 |
blocks the rotation around the respective base vectors of the element formulation. Is applied as weak boundary condition and summoned over all gauss points. | ElementNURBS_BRep_EdgeCoupling with ElementSurface_NURBS |
DIR_DIFF_SHELL8_X DIR_DIFF_SHELL8_Y DIR_DIFF_SHELL8_Z |
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Parameters DIRECTION | ||
Parameter | Description | Defined for |
DIRECTION_1 = float, float, float DIRECTION_2 = float, float, float |
This condition allows to limit translatoric movements of a point within a plane or a line. To this purpose a plane is defined by the parameter DIRECTION_1 naming the plane normal. If a second plane is defined by specifying DIRECTION_2 the point is only allowed to move an the intersection line of the two planes. | DISP_X, DISP_Y, DISP_Z |
Parameters CURVE | ||
Parameter | Description | Defined for |
LD-CURVE int | initial displacements are scaled by the global load factor * local load factor of the defined load curve. | DISP_X_NONZERO, DISP_Y_NONZERO, DISP_Z_NONZERO, DISP_X_NONZERO CLAMPED_TOR_NONZERO CLAMPED_X_NONZERO, CLAMPED_Y_NONZERO, CLAMPED_Z_NONZERO |
Example of a Complete Input Block
!=================================================================== ! ID DE-EL LOC COORD BC DE-SUP 1 1 u=0 DISP_X, DISP_Y, DISP_Z DE-SUP 2 1 u=0 v=1 w=1 DISP_X, DISP_Y, DISP_Z DE-SUP 3 1 DISP_X, DISP_Y, DISP_Z DE-SUP 4 1 DE-BREP 1 DISP_T1, DISP_T2, DISP_T3 DE-SUP 5 1 u=0 DISP_X_NONZERO = 0.25 LD-CURVE 2 DE-SUP 6 1 u=0 DISP_Y_NONZERO, DISP_Z_NONZERO !works only if DE-EL has a Reference-Patch (NURBS_REF) DE-SUP 7 1 u=0 DISP_X, DISP_Y, DISP_Z DIRECTION_1 = -1,0,1 DIRECTION_2 = 0,1,-1 !nodes can only move in direction of the vector [1,1,1] DE-SUP 8 1 DE-BREP 1 DISP_Y_NONZERO = 0.33 LD-CURVE 2 DE-SUP 9 1 DE-BREP 1 DISP_X, DISP_Y, DISP_Z DIRECTION_1 = -1,0,1 DIRECTION_2 = 0,1,-1 !brep element can only move in direction of the vector [1,1,1]
In order to activate boundary conditions which are not related to DesignBRepelements, they have to be added to the respective load combination.
LD-COM 1 TYPE=BC-DIRICHLET 1 TYPE=BC-DIRICHLET 2 TYPE=BC-DIRICHLET 3 TYPE=BC-DIRICHLET 5 TYPE=BC-DIRICHLET 6 TYPE=BC-DIRICHLET 7
In order to use boundary conditions for a set of nodes beside a specific one, a functionality for deactivation is added to the load combination. This can be used to in the design context for e.g. blocking the displacements of a whole design element but unleash the first node (u=0) from this restrictions. Note that this only work for boundary conditions on nodes and not for BRep boundary conditions.
LD-COM 1 TYPE=BC-DIRICHLET 3 TYPE=DEACT-BC-DIRICHLET 1
Automatic coupling of coincidenting control points of different design elements is received by
!=================================================================== ! ID EL1(Master) EL2 (Slave) DE-JOINT ALL_COOR !===================================================================
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