Reason

In welding simulations, the heated material is added to the welded workpiece.
To simulate this process, we introduce the following components into the framework:

• CSVPiecewiseLinearSpatioTemporalPath -- Defines the time-dependent path of the moving heat source based on a CSV input file. This user object enables interpolation of the source location over time.
• SpatioTemporalPathElementSubdomainModifier -- Dynamically modifies the subdomain of elements within a specified distance from the moving path.
• ADMovingEllipsoidalHeatSource -- Provides an ellipsoidal volumetric heat source localized around the current position of the path.
• ADMatHeatSource -- Inserts the volumetric heat source term into the weak form of the governing heat equation, linking it to the temperature field variable.

Design

These four components are combined into a single Action.
With this Action, users can simply specify parameters to automatically generate the path, apply mesh modifications, define the material response, and integrate the kernel for the welding simulations.

Impact

This approach makes welding simulations more user-friendly and easier to configure.