After you create or import an unmeshed geometry model, you must mesh the model before it can be analyzed.
Although you chose a mesh type when you imported the CAD model, the mesh has not been generated at this stage. The mesh consists of triangular elements connected with nodes, and provides the basis for the analysis. The three supported finite element mesh types are: Midplane, Dual Domain, and 3D.
The Generate Mesh pane of the Tools tab will open.
The Generate Mesh dialog allows you to preview the mesh, change the meshing parameters and save the parameters for future use.The mesh density should be optimized as far as possible. It is advisable to accept the default Global edge length as an initial estimate. This length is often too coarse and may have to be refined to 1/3 to 1/2 of the initial value. Alternatively, a Global edge length should be about 2 times the nominal wall thickness for a 3D mesh, and 2 to 5 times the nominal wall thickness for a Dual Domain mesh. You will now alter the mesh density.