ProductsAbaqus/StandardAbaqus/ExplicitAbaqus/CAE ConventionsCoordinate 1 is , coordinate 2 is . At the r-direction corresponds to the global x-direction and the z-direction corresponds to the global y-direction. This is important when data must be given in global directions. Coordinate 1 must be greater than or equal to zero. Degree of freedom 1 is , degree of freedom 2 is . Generalized axisymmetric elements with twist have an additional degree of freedom, 5, corresponding to the twist angle (in radians). Abaqus does not automatically apply any boundary conditions to nodes located along the symmetry axis. You must apply radial or symmetry boundary conditions on these nodes if desired. In certain situations in Abaqus/Standard it may become necessary to apply radial boundary conditions on nodes that are located on the symmetry axis to obtain convergence in nonlinear problems. Therefore, the application of radial boundary conditions on nodes on the symmetry axis is recommended for nonlinear problems. Point loads and moments, concentrated (nodal) fluxes, electrical currents, and seepage should be given as the value integrated around the circumference (that is, the total value on the ring). Element typesStress/displacement elements without twist
Active degrees of freedom1, 2 Additional solution variablesThe constant pressure hybrid elements have one additional variable and the linear pressure elements have three additional variables relating to pressure. Element types CAX4I and CAX4IH have five additional variables relating to the incompatible modes. Element types CAX6M and CAX6MH have two additional displacement variables. Stress/displacement elements with twist
Active degrees of freedom1, 2, 5 Additional solution variablesThe constant pressure hybrid elements have one additional variable and the linear pressure elements have three additional variables relating to pressure. Element types CGAX6M and CGAX6MH have three additional displacement variables. Diffusive heat transfer or mass diffusion elements
Active degrees of freedom11 Additional solution variablesNone. Forced convection/diffusion elements
Active degrees of freedom11 Additional solution variablesNone. Coupled thermal-electrical elements
Active degrees of freedom9, 11 Additional solution variablesNone. Coupled temperature-displacement elements without twist
Active degrees of freedom1, 2, 11 at corner nodes 1, 2 at midside nodes of second-order elements in Abaqus/Standard 1, 2, 11 at midside nodes of the modified displacement and temperature elements in Abaqus/Standard Additional solution variablesThe constant pressure hybrid elements have one additional variable and the linear pressure elements have three additional variables relating to pressure. Element types CAX6MT and CAX6MHT have two additional displacement variables and one additional temperature variable. Coupled temperature-displacement elements with twist
Active degrees of freedom1, 2, 5, 11 at corner nodes 1, 2, 5 at midside nodes of second-order elements 1, 2, 5, 11 at midside nodes of the modified displacement and temperature elements Additional solution variablesThe constant pressure hybrid elements have one additional variable and the linear pressure elements have three additional variables relating to pressure. Element types CGAX6MT and CGAX6MHT have two additional displacement variables and one additional temperature variable. Pore pressure elements
Active degrees of freedom1, 2, 8 at corner nodes 1, 2 at midside nodes Additional solution variablesThe constant pressure hybrid elements have one additional variable relating to the effective pressure stress, and the linear pressure hybrid elements have three additional variables relating to the effective pressure stress to permit fully incompressible material modeling. Element types CAX6MP and CAX6MPH have two additional displacement variables and one additional pore pressure variable. Coupled temperature–pore pressure elements
Active degrees of freedom1, 2, 8, 11 Additional solution variablesThe constant pressure hybrid elements have one additional variable relating to the effective pressure stress to permit fully incompressible material modeling. Acoustic elements
Active degrees of freedom8 Additional solution variablesNone. Piezoelectric elements
Active degrees of freedom1, 2, 9 Additional solution variablesNone. Nodal coordinates requiredr, z at Element property definitionFor element types DCCAX2 and DCCAX2D, you must specify the channel thickness of the element in the (r–z) plane. The default is unit thickness if no thickness is given. For all other elements, you do not need to specify the thickness. Input File Usage SOLID SECTION Abaqus/CAE Usage Property module: Create Section: select Solid as the section Category and Homogeneous as the section Type Element-based loadingDistributed loadsDistributed loads are available for all elements with displacement degrees of freedom. They are specified as described in Distributed loads. Distributed load magnitudes are per unit area or per unit volume. They do not need to be multiplied by . *dload
FoundationsFoundations are available for Abaqus/Standard elements with displacement degrees of freedom. They are specified as described in Element foundations. *foundation
Distributed heat fluxesDistributed heat fluxes are available for all elements with temperature degrees of freedom. They are specified as described in Thermal loads. Distributed heat flux magnitudes are per unit area or per unit volume. They do not need to be multiplied by . *dflux
Film conditionsFilm conditions are available for all elements with temperature degrees of freedom. They are specified as described in Thermal loads. *film
Radiation typesRadiation conditions are available for all elements with temperature degrees of freedom. They are specified as described in Thermal loads. *radiate
Distributed flowsDistributed flows are available for all elements with pore pressure degrees of freedom. They are specified as described in Pore fluid flow. Distributed flow magnitudes are per unit area or per unit volume. They do not need to be multiplied by . *flow
Distributed impedancesDistributed impedances are available for all elements with acoustic pressure degrees of freedom. They are specified as described in Acoustic and shock loads. *impedance
Electric fluxesElectric fluxes are available for piezoelectric elements. They are specified as described in Piezoelectric analysis. *decharge
Distributed electric current densitiesDistributed electric current densities are available for coupled thermal-electrical elements. They are specified as described in Coupled thermal-electrical analysis. *decurrent
Distributed concentration fluxesDistributed concentration fluxes are available for mass diffusion elements. They are specified as described in Mass diffusion analysis. *dflux
Surface-based loadingDistributed loadsSurface-based distributed loads are available for all elements with displacement degrees of freedom. They are specified as described in Distributed loads. Distributed load magnitudes are per unit area or per unit volume. They do not need to be multiplied by . *dsload
Distributed heat fluxesSurface-based heat fluxes are available for all elements with temperature degrees of freedom. They are specified as described in Thermal loads. Distributed heat flux magnitudes are per unit area or per unit volume. They do not need to be multiplied by . *dsflux
Film conditionsSurface-based film conditions are available for all elements with temperature degrees of freedom. They are specified as described in Thermal loads. *sfilm
Radiation typesSurface-based radiation conditions are available for all elements with temperature degrees of freedom. They are specified as described in Thermal loads. *sradiate
Distributed flowsSurface-based distributed flows are available for all elements with pore pressure degrees of freedom. They are specified as described in Pore fluid flow. Distributed flow magnitudes are per unit area or per unit volume. They do not need to be multiplied by . *sflow
Distributed impedancesSurface-based impedances are available for all elements with acoustic pressure degrees of freedom. They are specified as described in Acoustic and shock loads. Incident wave loadingSurface-based incident wave loads are available for all elements with displacement degrees of freedom or acoustic pressure degrees of freedom. They are specified as described in Acoustic and shock loads. If the incident wave field includes a reflection off a plane outside the boundaries of the mesh, this effect can be included. Electric fluxesSurface-based electric fluxes are available for piezoelectric elements. They are specified as described in Piezoelectric analysis. *dsecharge
Distributed electric current densitiesSurface-based electric current densities are available for coupled thermal-electrical elements. They are specified as described in Coupled thermal-electrical analysis. *dsecurrent
Element outputOutput is in global directions unless a local coordinate system is assigned to the element through the section definition (Orientations) in which case output is in the local coordinate system (which rotates with the motion in large-displacement analysis). See State storage for details. For regular axisymmetric elements, the local orientation must be in the –z plane with being a principal direction. For generalized axisymmetric elements with twist, the local orientation can be arbitrary. Stress, strain, and other tensor componentsStress and other tensors (including strain tensors) are available for elements with displacement degrees of freedom. All tensors have the same components. For example, the stress components are as follows: For elements with displacement degrees of freedom without twist:
For elements with displacement degrees of freedom with twist:
Heat flux componentsAvailable for elements with temperature degrees of freedom.
Pore fluid velocity componentsAvailable for elements with pore pressure degrees of freedom, except for acoustic elements.
Mass concentration flux componentsAvailable for elements with normalized concentration degrees of freedom.
Electrical potential gradientAvailable for elements with electrical potential degrees of freedom.
Electrical flux componentsAvailable for piezoelectric elements.
Electrical current density componentsAvailable for coupled thermal-electrical elements.
Node ordering and face numbering on elements
Numbering of integration points for outputFor heat transfer applications a different integration scheme is used for triangular elements, as described in Triangular, tetrahedral, and wedge elements. |