*SHELL SECTION
In ABAQUS/Standard the default is POISSON=0.5; in ABAQUS/Explicit the default is
POISSON=MATERIAL.
STACK DIRECTION
This parameter is relevant only for continuum shells.
This parameter defines the continuum shell stack or thickness direc tion. Set this parameter
equal to 1, 2, 3, or ORIENTATION.The default is STACK DIRECTION=3. The ORIENTATION
parameter must also be used if STACKDIRECTION=ORIENTATION.
SECTION INTEGRATION
Set SECTION INTEGRATION=SIMPSON (default)to use Simpson’s rule for the shell section
integration.
Set SECTION INTEGRATION=GAUSS to use Gauss quadrature for the shell section
integration. Gauss quadrature cannot be used for heat transferor thermally coupled shell elements.
TEMPERATURE
Use this parameter to select the mode of temperature and fieldvariable input used on the *FIELD,
the *INITIAL CONDITIONS, or the *TEMPERATUREoptions.
Omit the TEMPERATURE parameter to definethe predefined field by its magnitude on the
reference surface of the shell and its gradient through the thickness.
Set TEMPERATURE=n,wherenisthe number of predefined field variable poin ts in the shell
or in each layer if the COMPOSITE parameter is used, to define the predefined field at nequally
spaced points through each layer of the shell section.
In a heat transfer analysis step or a coupled temperature-displacement analysis step when
the *FIELD option is used to specify values of predefined field variables, the TEMPERATURE
parameter is required to specify the number of field variable points in the shell. The number of
temperature points in the shell with temperature degrees of freedom is defined bythe number of
integration points specified on the data lines.
THICKNESS MODULUS
This parameter is relevant only for continuum shells.
Set this parameter equal to an effective thickness modulus. The default effective thickness
modulus is twice the initial in-plane shear modulus based on the mater ial definition.
Data line to define a homogeneous shell (the MATERIALparameter is included):
First (and only) line:
1. Shellthickne ss. This value is ignored if the NODAL THICKNESS parame ter is included.
2. Number of integration points to be used through the shell section. The default is five point s if
Simpson’s rule is used and three points if Gauss quadrature is used. Thenumber of integration
points must be an odd number for Simpson’s rule and, in an ABAQUS/ Standard analysis, is
equal to the number of temperature degreesof freedom at a node of the element if this section
is associated with heat transfer or coupled temperature-displacement elements. This number
must be at least 2 and less than or equal to 7 for Gauss quadrature. ForSim pson’srule it mu st
18.15–3
ABAQUS Version 6.1 Module: ID:
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