Trelis 16.4 User Documentation
Internally, Trelis represents geometry as either ACIS solid model geometry or mesh-based geometry. Trelis can import ACIS geometry in the native "sat" file format. Trelis can also import STEP and IGES files and internally converts them into ACIS solid model geometry. For compatibility with Sandia legacy applications, Trelis can import FASTQ input decks to create ACIS geometry, as well. If you have geometry that has been created in another format, such as in SolidWorks, you will need to translate that geometry into something that Trelis can read. Many solid modeling packages have an Export ACIS .sat command, which is probably the easiest way of translating your model. If you do not have that option, there are some other possibilities.
Importing a Mesh