13.5. Joins - Bonded Face Connections

Bonded contact allows the nodes of an unstructured Part to be bonded to a face of another unstructured Part. Bonded contact alleviates the requirement that for joining purposes two nodes need to reside at the same physical location. The nodes that are to be bonded to a face may have an offset with respect to the face and the offset is a user-defined maximum physical normal distance of a node from a face which can be bonded together.

During the analysis the nodes are kept at the same relative position on the face to which they are bonded.

Bonds are allowed to fail and break upon a user-defined criterion.

Name

Enter a name for the bonded face connection set.

Maximum Offset

The automatic search algorithm for bonded regions will bond a node to the first face found within the specified offset distance. To ensure nodes are bonded to the nearest face, the value of the offset distance should be defined to be as small as possible.

Breakable

By default the bonded face connection will not be breakable. When the option Stress criteria is selected the bonded connection will fail and break upon a user-defined stress failure criterion:

  • Normal stress limit: maximum normal stress that can be sustained at the bond

  • Shear stress limit: maximum shear stress that can be sustained at the bond.

Failure of the bond occurs when:

(13–3)

where σn and σs are normal and shear stress at the bond Sn and Ss are the maximum allowed normal and shear stress limits and expn and exps are user defined exponential coefficients. The normal stress at the bond σn is nonzero for tensile values only.

Selection method

Bonded joins can be generated in Autodyn on a part basis as well as on a (multiple) face group basis.

Bonded Connections can also be defined in an Explicit Dynamic system and automatically transferred into a linked Autodyn system.


Note:
  • The element variable BOND_STATUS is used to record how many nodes are actively bonded to the faces of an element. This variable can be contoured to verify that bonds are correctly defined. If a bond fails during the simulation the bond status will show a reduction in the number of active bonds. When an element has no remaining bonds the value of BOND-STATUS is set to -1.0.

  • Bonded contact is available only with trajectory contact.

  • Bonded contact is available for unstructured volume, shell, and beam elements.



Release 16.2 - © SAS IP, Inc. All rights reserved.