Description: When modeling threaded bolt connections, the default contact normal directions that are generated by ABAQUS are not always appropriate. To effectively capture the effects of radial spreading and radial loading as a result of the actual thread contact direction and bolt tension loading (illustrated in Figure 11–3), it is usually necessary to redefine the contact normal direction at each slave node on the contact surface. The new bolt clearance modeling technique automatically generates the appropriate contact normal directions for a single-threaded bolt based on user-specified thread geometry data (Figure 11–4) and two points (labelled a and b in the same figure) defining a vector on the axis of the bolt and bolt-hole assembly.

Interaction module:
   Interaction editor: Clearance: Initial clearance: Computed for single-threaded bolt 
   or Specify for single-threaded bolt