17.6.2.26. Current

A Current load simulates the application of an electric current to a body.

This page includes the following sections:

Analysis Types

Current is available for the following analysis types:

For each analysis type, you define the Current by magnitude and phase angle in the Details pane, according to the following equation. (LS-DYNA systems only set a constant value, without phase or frequency.)

I = Iocos(ωt+φ)

Io is the magnitude of the Current (input value Current), ω is the frequency, and φ is the phase angle. For a static analysis, ωt = 0.

Magnetostatic Analysis Requirements

See Current Excitation for Solid Source Conductors and Current Excitation for Stranded Source Conductors.

Dimensional Types

The supported dimensional types for the Current boundary condition include:

  • 3D Simulation

  • 2D Simulation

Geometry Types

The supported geometry types for the Current boundary condition include:

  • Solid

Topology Selection Options

The supported topology selection options for Current include:

  • Face. An applied Current assumes that the body surfaces are equipotential.

  • Edge. An applied Current assumes that the edges are equipotential.

  • Vertex

Note:

  • Current loads assume that the scoped entities are equipotential, meaning they behave as electrodes where the voltage degrees of freedom are coupled and solve for a constant potential.

  • During an Electric or Thermal Analysis, it is assumed that the material properties of the body provide conductance. A positive current applied to a face, edge, or vertex flows into the body. A negative current flows out of the body.

Caution:  Current loads cannot be applied to a face, edge, or vertex that is shared with another voltage or Current load or a Coupling.

Magnitude Options

The supported Magnitude options for Current include the following:

  • Constant

  • Tabular (Time Varying)

  • Function (Time Varying)

Applying a Current Boundary Condition

To apply a Current:

  1. Select the Current option from the Environment Context tab. Alternatively, right-click the Environment tree object or in the Geometry window and select Insert>Current.

  2. Define the Scoping Method as either Geometry Selection or Named Selection and then specify the geometry.

  3. Enter a Magnitude value.

  4. Enter a Phase Angle value. (Phase will not be needed for LS-DYNA systems.)

Details Pane Properties

The selections available in the Details pane are described below.

CategoryProperty/Options/Description
ScopeScoping Method: Options include:

  • Geometry Selection (default): Default setting, indicating that the boundary condition is applied to a geometry or geometries, which are chosen using a graphical selection tool.

    • Geometry: Visible when the Scoping Method is set to Geometry Selection. Displays the type of geometry (Body, Face, etc.) and the number of geometric entities (for example: 1 Body, 2 Edges) to which the boundary has been applied using the selection tools.

  • Named Selection: Indicates that the geometry selection is defined by a Named Selection.

    • Named Selection: Visible when the Scoping Method is set to Named Selection. This field provides a drop-down list of available user-defined Named Selections.

Definition Type: Read-only field that displays boundary condition type - Current.

Magnitude

Phase Angle

Suppressed: Include (No - default) or exclude (Yes) the boundary condition.

Mechanical APDL References and Notes

The following Mechanical APDL commands, element types, and considerations are applicable for this boundary condition.

  • Currents are applied using a combination of F,,AMPS and CP,,VOLT commands when used in Magnetostatic analyses.

  • F,,AMPS and CE commands when used in Electric or Thermal-Electric analyses.

  • Magnitude (constant, tabular, and function) is always represented as a table in the input file.

LS-DYNA References and Notes

*EM_BOUNDARY_PRESCRIBED is used to implement the Current boundary condition.

API Reference

For specific scripting information, see the Current section of the ACT API Reference Guide.