Adjusting the fastener definition

You use the Adjust tabbed page to specify the orientation of the fastener. For a description of how you can combine connector orientations and fastener orientations, see Defining the fastener orientation. You can also specify how Abaqus will compute the radius of influence, which determines the group of nodes that will be associated with each fastening point.

Related Topics
About fasteners
Understanding attachment points and lines
In Other Guides
Mesh-independent fasteners

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

  2. By default, Abaqus determines the orientation of each fastener from the default local directions of the surface that is closest to the fastening point. Click to select a datum coordinate system (CSYS) that specifies the orientation of the fastener. Click to create the datum coordinate system if it does not already exist. The z-axis of the CSYS should be approximately normal to the surfaces that are being connected, and the local x- and y-axes should be approximately tangent to the surfaces that are being connected.

  3. By default, Abaqus adjusts the orientation that you specified such that the local z-axis for each fastener is normal to the surface that is closest to the fastening point. Toggle off Adjust CSYS to make Z-axis normal to closest surface to use the selected coordinate system to define the local directions precisely.

  4. Each fastening point is associated with a group of nodes on the surface in the immediate neighborhood of the fastening point called a region of influence. The motion of the fastening point is then coupled in a weighted sense to the motion of the nodes in this region by a distributed coupling constraint. Each region of influence contains a minimum of three nodes. Choose either of the following to define the region of influence:

    • Choose Facet-based default to allow Abaqus to compute an internal radius of influence based on the geometric properties of the fastener, the characteristic length of the connected facets, and the weighting method you selected. The default radius of influence is always chosen to be the largest of the internally computed radius of influence, the physical fastener radius, and the distance from the projection point to the closest node.

    • Choose Specify, and enter the radius of influence. If you specify a radius of influence that is smaller than the computed default radius of influence, Abaqus uses the computed value.

    For more information, see Defining the radius of influence.