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External solvers

WELSIM is a simulation software that supports multiple solvers and is one of the most comprehensive and widely compatible pre- and post-processing tools for open-source solvers in the world. Currently supported open-source solvers include FrontISTR, Elmer FEM, OpenRadioss, CalculiX, SU2, and LAMMPS. Each of these solvers offers distinct features and advantages, allowing users to choose the one that best suits their needs. Thanks to WELSIM’s powerful pre- and post-processing capabilities, the time required for modeling when using these solvers is significantly reduced.

This section primarily introduces the details and usage methods of external solvers.

Configuration

When invoking external solvers, a simple configuration of the solver paths is required. Users only need to go to the Preferences interface, select Solvers, and configure the solvers accordingly. The configuration interface is shown below.

finite_element_analysis_welsim_preferences_solvers

The details of each supported solver are summarized below. This table also provides information on the integration method and the level of support for each solver.

Solver Download Site Connection Type Pre-processing Post-processing
Elmer FEM https://elmerfem.org Path Yes No
OpenRadioss https://openradioss.org Path Yes Yes
FrontISTR https://elmerfem.org File Yes Yes
CalculiX https://calculix.de File Yes No
Palace https://awslabs.github.io/palace File Yes Yes
SU2 https://su2code.github.io File Yes Yes
LAMMPS https://lammps.org File Yes No

Default solver

For different types of simulation analyses, WELSIM automatically sets a default solver. However, users can also manually specify the solver to be used. As shown in the figure below,

finite_element_analysis_welsim_study_settings_solvers

When the user selects Program Controlled, the system automatically assigns a solver based on the following logic:

  1. If the analysis type is structural and explicit transient is not enabled, the system automatically uses the FrontISTR solver.
  2. If the analysis type is explicit structural dynamics, the system automatically uses the OpenRadioss solver.
  3. If the analysis type is thermal, the system automatically uses the FrontISTR solver.
  4. For fluid analysis types, the system automatically uses the SU2 solver.
  5. For electromagnetic analysis types, the system automatically uses the Palace solver.
  6. When the project type is molecular dynamics, the system automatically uses the LAMMPS solver.

WelSim is not directly affiliated with Elmer FEM, FrontISTR, OpenRadioss, CalculiX, Palace,SU2, and LAMMPS. References to these open source solvers are solely for technical blog purposes and software usage guidance.