Fillet and Seam Welds
In SimSolid, seam welds are modeled as full 3D solid bodies.
Welds are defined by section size and length along the edge. A minimum weld edge length can be specified. Simple trapezoidal shapes are used to represent the welds. You can pick weld material properties from the SimSolid material database. Otherwise, material properties are automatically taken from the adjacent parts while solving.
As of version 2020.2, you can create seam welds on curvatures with no feature lines. They are created from lines/solids, which you can create in the Assembly workbench toolbar, or import from an XML file.