Operator CARA DATE 98/10/09 Opérateur CARACTERISTIQUE See also :MODE VMIS ------------------------- MATE CAR1 = CARA MODL1 NOMCi VALi ... ; Description : ____________ The CARA operator enables the construction of the CAR1 object of MCHAML type; it describes features that cannot be deduced from the mesh. These properties will characterize the MMODEL MODL1 object. Contents : _________ MODL1 : model object (MMODEL type) NOMCi : name of the ith component (MOT type) VALi : value of the ith component (FLOTTANT type) CAR1 : object with the geometrical properties (MCHAML type, CARACTERISTIQUES subtype) ----------------------------------------- | Feature name for the solid elements | ----------------------------------------- ('DIM3') : thickness in the case of plane stresses ----------------------------------------------------------- | Feature names for the COQ2, COQ3, COQ4, DKT, DST elements | ----------------------------------------------------------- 'EPAI' : shell thickness ('ALFA') : coefficient used for the plasticity criterion (2/3 by default) ('EXCE') : offset of the mid-plane with respect to the reference plane regarded as positive in the direction of the normal (not available for COQ3) ('DIM3') : thickness in the other direction (case of COQ2, plane stresses) -------------------------------------------- | Feature names for the COQ6, COQ8 elements | -------------------------------------------- 'EPAI' : shell thickness ('EXCE') : offset with respect to the mid-plane regarded as positive in the direction of the normal ---------------------------------------------- | Feature names for the QUAS or TRIS elements | ---------------------------------------------- The section is described in the xOy plane. The Ox axis of the section system is the local axis Oy of the TIMO element. 'ALPY' : coefficient multiplying the shear stress sxy (Ox et Oy are local axis of the TIMO element). 'ALPZ' : coefficient multiplying the shear stress sxy (Ox et Oz are local axis of the TIMO element). In the case of a homogeneous section these coefficients may be calculated using Timoshenko theory. --------------------------------------------------- | Feature names for a BARRE element (BAR) ou BAR3 | --------------------------------------------------- 'SECT' : cross section --------------------------------------------------- | Noms des caractéristiques pour un élément BAEX | --------------------------------------------------- 'SECT' : cross section 'EXCZ' : offset of the axis along the local axis z 'EXCY' : offset of the axis along the local axis y 'VX ' : x component of the second vector of the local frame 'VY ' : y component of the second vector of the local frame 'VZ ' : z component of the second vector of the local frame ----------------------------------- | Feature names for a CERCE element| ----------------------------------- 'SECT' : cross section ------------------------------------------------------------- | Feature names for the POUTRE or TIMO element (BEAM or TIMO)| ------------------------------------------------------------- The beam features are defined in the element local axes (Ox stands for the beam axis oriented from the first point towards the second, Oy is defined by the user when necessary, Oz completes the basis). Axis Oy and Oz must be principal axis because the crossing moments of inertia are not given (except for the TIMO element in the case of a SECTION model). 'SECT' : cross section 'INRY' : moment of inertia with respect to the local axis Oy 'INRZ' : moment of inertia with respect to the local axis Oz 'TORS' : twisting moment of inertia ('SECY') : reduced section used to compute shear force according to the local axis Oy ('SECZ') : reduced section used to compute shear force according to the local axis Oz ('VECT') : key word for defining the local axis Oy. It must be followed by a vector pertaining to the xOy plane (POINT type object) ('DX ') | : 3 distances to compute stresses from the moments ('DY ') | for the plasticity criterion ('DZ ') | (see VMIS). The default value of the SECY and SECZ for the TIMO element is SECT, and for the POUTRE element we do not considerate the shear deformation potential energy (this is equivalent with giving infinite values for the reduced sections. ----------------------------------- | Feature names for a TUYAU element| ----------------------------------- This element is used in the modeling of parts of straight pipe or elbow which differ only in their radius curvature. The pipe features are defined in the element local axes, in the same way as the POUTRE element. 'EPAI' : thickness 'RAYO' : pipe external radius ('RACO') : if elbow, radius of curvature ('VECT') : key word for defining the local axis. It must be followed by a POINT type object modeling an xOy vector. This is especially required when dealing with an elbow. Caution : for elbows, the local vector Oz, deduced -------- from Ox and Oy is situated in the elbow plane and is oriented, according to convention, towards the elbow extrados. ('PRES') : internal pressure (0. by default) ('CISA') : multiplicative factor of the reduced section used to to compute shear forces (0. by default) ('CFFX') : coefficient to compute the membrane stress from the EFFX force, for the plasticity criterion (1. by default), (see VMIS). ('CFMX') : coefficient to compute the torsion stress from the MOMX moment, for the plasticity criterion (3.**0.5 by default), (see VMIS). ('CFMY') : coefficient to compute the flexion stress from the MOMY moment, for the plasticity criterion ((pi/4)*gamma by default), (see VMIS). ('CFMZ') : coefficient to compute the flexion stress from the MOMZ moment, for the plasticity criterion ((pi/4)*gamma by default), (see VMIS). ('CFPR') : coefficient to compute the circumferential stress induced by the pressure. This coefficient is not used for the plasticity criterion but is used for the equivalent stress calculation. ((2.**0.5)/2. by default), (see VMIS). Remark : for CFMY and CFMZ, gamma is equal to 1. for ------- straight parts and to maxi ( 1., (8/9)/lambda**2/3 ) for elbows, with lambda = epai*raco/rmoy**2 where rmoy is the pipe mean radius. ---------------------------------------- | Feature names for a LINESPRING element| ---------------------------------------- 'EPAI' : shell thickness 'FISS' : notch depth 'VX ' | 'VY ' | : components a vector normal to the LISP plane: its direction 'VZ ' | indicates the side of the element where the notch opens. Note : _______ The distance between two opposite nodes of the linespring must be greater than 1.e-6 and smaller than 1.e-3 times the length of the linespring. The element is then oriented by the following rule : x is the axis from point 1 to point 2 of the element, y is oriented through the given vector (VX VY VZ), z is the vectoriel product between x and V. If the given vector is oriented in the opposite direction than the positive normal vector of the element (vector N) then an error message is issued while computing stresses (operator SIGM), indicating that (x,N,z) is not direct, however values are correct. Angles must not be smaller than 175 degrees or greater than 185 degrees between the elements in their plane (defined with the normal vector). ------------------------------------------- | Feature names for a TUYAU FISSURE element| ------------------------------------------- This element enables the modeling of parts of straight pipe or cracked elbow which differ only in their radius of curvature. The pipe features are defined in the element local mark POUTRE. 'EPAI' : thickness 'RAYO' : pipe external radius 'ANGL' : crack whole opening in degrees 'VX ' | 'VY ' | : components of the vector defining the cracked pipe 'VZ ' | axis 'VXF ' | 'VYF ' | : components of the vector defining the orientation 'VZF ' | of the crack Note : ______ The validity domain for this element is corresponding to a ratio RAYO/EPAI between 5.5 and 20.5. -------------------------------------- | Feature names for a RACCORD element | -------------------------------------- For elements of fluid-structure coupling different from LITU, it is necessary that the fluid position be known with respect to the coupling element. For this, the geometrical object modeling the fluid will be provided after the key word 'LIQU'. ----------------------------------- | Feature names for a LSE2 element | ----------------------------------- 'RAYO' : pipe internal radius ('RACO') : if elbow, radius of curvature ------------------------------------ | Feature names for a LITU element | ------------------------------------ 'RAYO' : pipe internal radius ('RACO') : if elbow, radius of curvature ('VECT') : key word for defining the local axis Oy. It must be 'VZ ' | followed by an object of POINT type modeling a vector xOy. This is especially required when dealing with an elbow. Caution : for elbows, the local vector Oz deduced from ------- Ox and Oy, is situated in the elbow plane, and, according to convention is oriented towards the elbow extrados. ----------------------------------------------- | Feature names for a HOMOGENEISE element TRIH | ----------------------------------------------- 'SCEL' : measurement of an enlarged elementary cell 'SFLU' : measurement of the fluid in the enlarged cell 'EPS ' : tubular step of the medium 'NOF1' : ratio between the norm of the tube modal deformed shape and the norm of the pressure according to the axis of the tubes 'NOF2' : ratio between the scalar product of the tube modal deformed shape and the pressure modal deformed shape according to the axis of the tubes Note : ________ Note that when studying a slab, both 'NOF1' and 'NOF2' coefficients equal one. ------------------------------------------------------- | Feature names for a HOMOGENEISE element QUAH or CUBH | ------------------------------------------------------- 'SCEL' : measurement of an enlarged elementary cell 'SFLU' : measurement of the fluid in the enlarged cell 'EPS ' : tubular step of the medium 'SECT' : cross section of one beam 'INRZ' : moment of inertia with respect to the axis Oz