What is the difference between bonded contact region and fixed joint
I need to connect different parts for a project, and I noticed that there are 2 options. One is using the bonded contact region and one is using the fixed joint. Both can be used for surfaces so I am wondering what the exact difference is. I've done a test by connecting two parts and then calculating some modes (as I need to do modal analysis) and compared the connection methods to see if the result would be the same, but it is not.
I did find this through Ansys help:
Bonded: This is the default configuration and applies to all contact regions (surfaces, solids, lines, faces, edges). If contact regions are bonded, then no sliding or separation between faces or edges is allowed. Think of the region as glued. This type of contact allows for a linear solution since the contact length/area will not change during the application of the load. If contact is determined on the mathematical model, any gaps will be closed and any initial penetration will be ignored. [Not supported for Rigid Dynamics. Fixed joint can be used instead.]
The last line indicates that both can be used for similar purpose but that bonded contact region is not supported for Rigid Dynamics.
Can someone explain to me what the exact difference is?