# Geometry – Lesson 3

### Geometry

Drag Static Structural into the Project Schematic page right next to External Model.

In the Project Schematic page, click and drag Setup from External Model and drop it onto Model in Static Structural.

This will load the External Model into Ansys Mechanical. When the External Model is linked with Model in Static Structural, the geometry and mesh in the External Model is transferred to Mechanical and the user can proceed straight to setting up the physics.

Notice there is a lightning bolt symbol on the External Model. Right click on Setup and select Update.

Under Static Structural, right click on Model > Properties. The Tolerance Angle is set to 45.

This value determines if adjacent elements are of the same face during the geometry creation process. Since the original mesh had no associated geometry, geometry is synthesized (created). The skin detection algorithm scans the exterior element facets and groups them based on the tolerance angle. By reducing the tolerance angle, we end up with more geometric faces to represent the curvature of the body. By increasing the tolerance angle to a limit of 180°, only a single geometric face will be generated for the whole body. Since the bone mesh is made of regular shaped cubes with repeating element face normals of zero and 90 degree angles , the adjacent element facets are less than 45 degrees and will be grouped together. This makes selection of the numerous element facets easier for the application of boundary conditions, since these facets (element faces) are now associated with a larger geometric face that encompasses them and represents a continuous face, which can be more conveniently selected for the application of boundary conditions. We can leave the tolerance angle as the default value of 45.

You may now move on to the next step