Predefined Fields for Sequential Coupling

The time history of the following nodal output quantities, generated in an Abaqus/Standard analysis, can be read into subsequent Abaqus/Standard analyses as predefined fields for sequentially coupled multiphysics workflows:

  • Temperature

  • Normalized concentration

  • Electric potential

Alternatively, the time history of a known pore fluid pressure field can be read into a subsequent Abaqus/Standard static or an Abaqus/Explicit dynamic stress analysis as a predefined field to perform a sequentially coupled pore pressure–stress analysis.

A sequentially coupled multiphysics analysis can be used when the coupling between one or more of the physical fields in a model is only important in one direction—a special common case is a sequential thermal-stress analysis (Sequentially Coupled Thermal-Stress Analysis). While the uncoupled thermal-stress analysis is the most common sequential multiphysics workflow, the predefined field capability in Abaqus/Standard directly supports similar sequential workflows involving normalized concentrations (Mass Diffusion Analysis) and electric potentials (Coupled Thermal-Electrical Analysis). As with temperatures, normalized concentrations and electric potentials can be read from the output database (.odb) file into subsequent analyses as predefined fields.

When defined by results from a previous analysis, predefined fields typically vary with position and are time dependent—they are predefined because they are not changed by the current analysis. When predefined fields are read from a previous analysis, they are read in at the nodes. They are then interpolated within elements as needed (see Interpolating Data between Meshes). Any number of predefined fields can be read in, and material properties can be defined to depend on them. In addition, volumetric strain will arise in a stress analysis if thermal expansion (Thermal Expansion) or field expansion (Field Expansion) are included in the material property definition.

Predefined fields may affect the system response through:

  • the constitutive behavior, such as the yield stress defined as a function of temperature or field variables; or

  • volumetric strains when thermal or field expansion behaviors (Thermal Expansion and Field Expansion) are included in the material definition in a stress/displacement analysis; or

  • a modification to the stress field when a pre-computed pore fluid pressure field is read into an Abaqus stress analysis as a predefined field variable.

This page discusses:

Saving Temperatures, Normalized Concentrations, and Electric Potentials for Predefined Fields in Subsequent Analyses

Nodal temperatures, normalized concentrations, and electrical potentials can be stored as functions of time for use in subsequent analyses. Temperatures can be stored in either the results (.fil) file or the output database (.odb) file, but normalized concentrations and electrical potentials can be used only if they are stored in the output database file. Saved values must be read into the new analyses as predefined fields. See Node Output and Writing Nodal Output to the Output Database.

Saving Temperatures for Predefined Fields in Subsequent Analyses

Saving Normalized Concentrations for Predefined Fields in Subsequent Analyses

Saving Electric Potentials for Predefined Fields in Subsequent Analyses

Transferring Temperatures as Temperature Fields

Transferring Temperatures, Normalized Concentrations, and Electric Potentials from the Output Database to Predefined Fields

Transferring Pore Fluid Pressure to a Predefined Field

Initial conditions

Boundary conditions

Loads

Predefined fields

Material Options

Elements

Input File Template