Learning Forum

[peteroznewman]

Jack,

To avoid artificial stress, replace Bonded Contact with Frictional Contact. Below are brief comments on riveting.

Deforming the Rivet: To create a permanent joint, the rivet needs to be deformed or “set.” This is typically done by applying a large force to the protruding end of the rivet. The force can be applied using various methods, such as manual rivet guns, pneumatic or hydraulic tools, or even automated machinery. As the force is applied, the tail end of the rivet is deformed, which causes the shaft of the rivet to expand and fill the hole, creating a secure and tight connection between the plates.

Residual Compression: During the process of deforming the rivet, a significant amount of force is applied. This force causes the rivet to plastically deform and create a tight joint. Additionally, some residual compression is locked into the structure as a result of the deformation. This residual compression helps to maintain the integrity and strength of the joint over time, even under loads and vibrations.

Are you interested in simulating the residual compression?  If you have a rivet shaft that is the same diameter as the holes and the length of the rivet shaft is the same as the thickness of the two plates, there will be no residual compression. This may result in a larger deformation of the tip of the plate due to a tip force than you might get from the real parts.

You can make a rivet shaft diameter that is slightly larger than the hole diameter and a rivet shaft length that is slightly shorter than the two plate thickness dimension. As the frictional contact resolves the interference, a compression stress will be developed. This may result in a smaller deformation of the tip of the plate with a tip force compared with the non-interfering geometry.