Users:Geometry Generation/Design Supports

From Carat++ Public Wiki
Jump to: navigation, search

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
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
!===================================================================




Whos here now:   Members 0   Guests 1   Bots & Crawlers 0
 
Personal tools
Content for Developers