Conversion from FreeCAD to COMSOL Multiphysics is not supported yet :(

FreeCAD is a customizable, open-source paramentic 3D CAD and BIM software with FEM support, built on the Opencascade geometric kernel. It was created primarily for product design and mechanical engineering, but it can be used in a wide range of industries, such as electrical engineering, or architecture. It runs on Windows, Mac OS, and Linux.

FreeCAD is made to craft real-life objects of different sizes and is perfect for a home user/amateur, programmer, experienced CAD software user, or educator. This software provides tools similar to those of SolidWorks, Catia or Autodesk Revit.

COMSOL Multiphysics® is a general-purpose simulation software for modeling designs, devices, and processes in all fields of engineering, manufacturing, and scientific research. In addition to using multiphysics modeling for your own projects, you can also turn your models into simulation applications and digital twins for use by other design teams, manufacturing departments, test labs, customers, and more.

The platform product can be used on its own or expanded with functionality from any combination of add-on modules for simulating electromagnetics, structural mechanics, acoustics, fluid flow, heat transfer, and chemical engineering. The add-on modules and LiveLink™ products connect seamlessly for a modeling workflow that remains the same regardless of what you are modeling.