ERESX
ERESX, Key
Specifies extrapolation of integration-point results.
KeyExtrapolation key:
DEFA
—
If element is fully elastic (no active plasticity, creep, or swelling nonlinearities), extrapolate the integration-point results to the nodes. If any portion of the element is plastic (or other active material nonlinearity), copy the integration-point results to the nodes (default).
YES
—
Extrapolate the linear portion of the integration-point results to the nodes and copy the nonlinear portion (for example, plastic, creep, and/or swelling strains).
NO
—
Copy the integration-point results (elastic and inelastic) to the nodes.
Command Default
Extrapolate integration-point results to the nodes for all elements except those with active plasticity, creep, or swelling nonlinearities (default). See Notes for details.
For coupled pore-pressure-thermal elements (CPT212, CPT213, CPT215, CPT216, CPT217), the default behavior is to copy integration-point results to the nodes.
Notes
Specifies whether the solution results at the element-integration points are extrapolated or copied to the nodes for element and nodal postprocessing. This setting affects structural stresses, elastic and thermal strains, field gradients, and fluxes.
The MAPDL solver uses a tolerance check to determine whether extrapolation is permitted. By default, if the inelastic strains, defined as plastic, creep or swelling strains, exceed 10−12, extrapolation from the integration points to the nodes is discontinued, and all results (both elastic and inelastic) are copied to the nodes. Otherwise, results that support extrapolation are extrapolated as specified by ERESX. Inelastic strain results, including plastic and creep and swelling strains results, are always copied to the nodes rather than extrapolated.
For shell elements, ERESX applies only to integration-point results in the in-plane directions.
Extrapolation occurs in the element-solution coordinate system. For elements allowing different solution systems at integration points (such as SHELL281 and SOLID186), extrapolation can produce unreliable results when the solution coordinate systems in each element differ significantly. (Varying element-solution coordinate systems can be created via the ESYS command or from large deformation.) Examine results carefully in such cases, and disable extrapolation if necessary.
This command is also valid in PREP7.