To define the fastener formulation:

1. From the Edit Fasteners dialog box, display the Formulation tabbed page.

2. Choose the method to couple the motion of the fastening points to the average motion of the nodes on the surfaces that fall inside the influence radius.

   • Choose Continuum distributing (default) to couple the displacement and rotation of the fastening points to the average displacement of the nodes.

   • Choose Structural distributing to couple the displacement and rotation of the fastening points to the average displacement and rotation of the nodes.

   For more information, see “Defining the surface coupling method” in “Coupling constraints,” Section 35.3.2 of the Abaqus Analysis User's Guide.

3. If desired, toggle off a rotational degree of freedom to remove its constraint. Abaqus/CAE always constrains all translational degrees of freedom in a fastener.

4. Choose the weighting method that Abaqus will use to modify the default weight distribution at the coupling nodes within the radius of influence.

   • Choose Uniform (default) to select a weight distribution that is uniform and equal to 1.0.

   • Choose Linear to select a weight distribution that decreases linearly with distance from the fastening point.

   • Choose Quadratic to select a weight distribution that decreases by a quadratic polynomial function with distance from the fastening point.

   • Choose Cubic to select a weight distribution that decreases by a cubic polynomial monotonic function with distance from the fastening point.

   For more information, see “Weighting methods” in “Coupling constraints,” Section 35.3.2 of the Abaqus Analysis User's Guide.