The bonded contact condition in SolidWorks Simulation can be used to accurately handle load transfer in a multitude of cases where bodies stay in contact such as welded or glued bodies among others. The software achieves this through two methods; aligning the meshes of the two bodies hence bonding the nodes of the two bodies (compatible) or by applying equivalent internal equations to the contact interface to achieve the same result (incompatible). The latter is of course used in situations when the mesh does not allow for compatible bonding. You can control when to use which inside of the property manager by selecting the options at the bottom.
Incompatible bonding is achieved in two ways as well. Simplified bonding applies the equation only at the nodes which lie completely within an element on the opposite body while mortar or more accurate bonding applies the equation at all the nodes down the entire line of contact between the two bodies. Through the study properties, you can choose to use either option or leave it up to the software by selection the automatic option.
In the case when a mid-surface is used to mesh the body with shell elements, it is paramount that this is accounted for when using the bonded condition. While the two bodies might be clearly touching, the mid-surface is NOT the contact surface and so applying the bonded condition directly on it will over stiffen the study. In this case, you must use the offset option when defining the shell to account for the gap between the mid-surface and the contact surface.
Simply select the surface used to create the shell and then insert the distance between it and the contact surface and the software will account for this mass when applying the bonded condition as the load is transferred from one body to another.
Applications Engineer, CATI