$$$$ RELA NOTICE BP208322 12/12/17 21:15:21 7615 DATE 12/12/17 Operateur RELA Voir aussi : BLOQ REAC -------------- SYMT RESO ANTI COLLER The RELA operator has two functions : ---------------- | 1st function | ---------------- RIG1 = RELA | | (VAL1) | MOT1 | GEO1 ... |'MINI'| | 'DEPL' |'DIRECTION' VEC1 | |'MAXI'| | 'ROTA' | | | + | (VAL2) | MOT2 | GEO2 ... | - | | 'DEPL' |'DIRECTION' VEC2 | | 'ROTA' | | Description : _____________ The RELATION operator enables the user to construct the stiffness associated with a linear relation between the unknowns of MOTi names weighted by (possible) coefficients VAL1, VAL2 ..., or respective mesh nodes GEO1, GEO2, (c.f. the example) ... Contents : _________ MOTi : unknown names (MOT type) VALi : weighting coefficients (ENTIER or FLOTTANT type) VECi : enables the user to connect the displacement (key word 'DEPL') or the rotation (key word 'ROTA') in the VEC1 (POINT type) direction GEOi : geometries (MAILLAGE type) having all the same number of nodes RIG1 : generated object (RIGIDITE type) to be added to the stiffness of the structure for the solution Note : _______ The DEPIMP operator allows the user to impose a non-zero value on the relation. The relation may be either of equality or inequality type (case of unilateral relations) with the key words 'MINI' or 'MAXI'. Example : _________ REL1 = RELA MINI 2.5 UX L1 - UY L2 + 3 UX L3 ; JEU1 = DEPIMP REL1 0.3 ; The corresponding inequalities are : 2.5*UX(node i of L1)-UY(node i of L2)+3*UX(node i of L3) >EG 0.3 for i=1,...,number of nodes of L1 (and L2, L3, ... too) Creation of a relation from a CHPOINT _____________________________________ RIG1 = RELA | 'MAXI' | CHPO1 ; | 'MINI' | Description : _____________ The RELATION operator enables the user to construct the stiffness associated with a linear relation between the unknowns whose names are those of the components of the field by points CHPO1 (CHPOINT type) at the points which are those of the field and which are weighted by the values of this field at these points. The relation may be either of equality or inequality type (case of unilateral relations) with the key words 'MINI' or 'MAXI'. CORI option ___________ RIG1 = RELA 'CORI' 'DEPL' | ('NOVERIF') GEO1 ; | | 'ROTA' GEO1 (GEO2) ; Description : ____________ The 'CORI' option of the RELA operator enables the user to construct the stiffness RIG1 (RIGIDITE type) associated with a rigid body motion for a geometry : If the key word 'ROTA' is not given the rigid body motion is ensured by imposing that the distance between the nodes remain constant. For this, at least 4 non-coplanar points are requested in 3D as well as 3 non-colinear points in 2D (if this is not the case, use the word 'NOVERIF', but the result may not be the one expected). This option must be used when rotations are not included in the degrees of freedom of the problem. If the key word 'ROTA' is given the rigid body motion is ensured by imposing that the degrees of freedom of GEO1 (MAILLAGE or POINT type with rotational degrees of freedom) and of GEO2 (MAILLAGE type without rotational degrees of freedom/optional) are the elements of reduction of the same distributor defined by the displacements and rotations at a master point of GEO1. ENSE option ___________ RIG1 = RELA 'ENSE' MOT1 GEO1 ; Description : _____________ The 'ENSE' option of the RELA operator enables the user to construct the stiffness RIG1 (RIGIDITE type) associated with an global motion : the value on the degree of freedom MOT1 (MOT type) is imposed as being identical for all the nodes of GEO1 (MAILLAGE type). option ACCRO ___________ RIG1 = RELA GEO1 'ACCRO' GEO2 ( LMOTS ) (FLOT1) ; RIG1 = RELA 'ACCRO' 'FORT' MODL2 | GEO1 ; | MODL1 ; Description : _____________ 'ACCRO' option allows to build the stiffness associated to the binding of mesh GEO1 upon mesh GEO2 . Any GEO1 point contained in a GEO2 element is bound to follow a linear combination of its nodes displacements. Eventually LMOTS (LISTMOTS type ) list of DOF concerned. Default: the DOF of mechanic (2D : UX UY or UR UZ if axisymmetrical; 3D : UX UY UZ ) FLOT1 optional floating number allows to bind nodes slightly out of geo2 boundary . ( default value 1.e-5) - must stay small if used With the keyword FORT, nodes of GEO1 (or of modele MODL1) are binded to the elements of modele MODL2. It takes into account the possible enrichment XFEM (jump + crack-tip functions) of MODL2. NOTA: this operation can be time consuming , if possible do not ask binding of nodes obviously outside of GEO2 option GLISSANT ___________ RIG1 = RELA GEO1 'GLISSANT' GEO2 ( LMOTS ) (FLOT1) ; Description : _____________ 'GLISS' option allows to build the stiffness associated to the sliding of mesh GEO1 upon mesh GEO2 . GEO1 is compound of seg2 or seg3 elements.Any GEO1 point contained in a GEO2 element is only allowed to slide along itself and is bound to follow a linear combination of GEO2 nodes displacements in perpendicular directions. FLOT1 optional floating number allows to bind nodes slightly out of geo2 boundary . ( default value 1.e-5) - must stay small if used NOTA : this operation can be time consuming , if possible do not ask binding of nodes obviously outside of GEO2 option MILI ___________ RIG1 = RELA MILI (LISMOT1) GEO1 ; Description : _____________ The MILI option builds the stiffness which links linearly the DOF of the midside nodes of a quadratic mesh (GEO1) to its vertices. The DOF are specified by the LISTMOTS. By default, the DOF of concerned are the displacments. REMARK: This option is useful to model problems involving contact while using quadratic elements. Since the mesh of contact is built from linear elements, the displacments of the midside nodes of the quadratic elements describing the structures have to be constrained to follow linearly the displacments of the vertices. option TUYA ___________ RIG1 = RELA TUYA GEOM1 GEOM2 CRIT; Assuming a pipe (GEOM1 seg2 or seg3) in which the temperature of the fluid can be considered constant this operation will impose that each points of GEO2 has the same temperature as its projected point on the line. The distance between one point and its projected one must be less than CRIT. ----------------- | 2nd function | ----------------- ATTA1 = RELA ELSTR1 MOT1 LREEL1 BLSTR1 'LX' LREEL2 .... ... .... ; The RELA operator describes an elementary linkage between one (or several) substructure(s). It creates an ATTA1 object of ATTACHE type. Contents : __________ ELSTR1 : ELEMSTRU type object created by the ELST operator MOT1 : component of the point(s) of ELSTR1 LREEL1 : values of the coefficients applied to each point of ELSTR1 (LISTREEL type) If there is only one point in ELSTR1, a FLOTTANT number may be provided BLSTR1 : BLOQSTRU type object created by the CLST operator 'LX' : compulsory component for a restraint LREEL2 : values of the coefficients applied to the points created when applying a restraint by the BLOQUE operator (LISTREEL type)
© Cast3M 2003 - All rights reserved.
Disclaimer