About Surface-Based Contact and Bonded Contact

Surface-based contact defines a connection between surfaces in very close proximity. Bonded contact is a type of surface-based contact in which the surface of one component attaches to the surface of another component permanently. In a thermal simulation, a surface-based contact feature defines a common interface between two parts across which heat can be conducted.

See Also
Defining Surface-Based Contact or Bonded Contact by Detecting Contact
Defining Surface-Based Contact or Bonded Contact by Selecting Surfaces

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A bonded contact consists of two surfaces on two separate part bodies. These two surfaces remain firmly attached to one another during a simulation, as if they were glued or welded together. The surfaces might stretch, bend, or deform together during the simulation, but they never move relative to each other. Bonds represent the most basic connection between components, essentially joining two components into a single component at a common interface.

Surface-based contact in a thermal simulation consists of two surfaces on two separate part bodies. Heat is transferred between the two components across these surfaces according to a conductance value you can specify. A higher conductance indicates an easier transfer of heat between components, while a conductance of zero prevents heat from transferring across the surfaces. If surface-based contact is not defined in a model, temperature changes and heat fluxes on one component do not affect adjacent components.

The two surfaces in a contact definition should be touching in the assembled product. See About Proximity and Orientation Requirements.

Only the common interface of two surfaces connect during a simulation; surface regions that do not overlap are excluded automatically from the contact definition. Consider the two crossing bars in the following image (left). The surfaces selected for contact overhang each other significantly (center). During the simulation, only the regions of the surfaces that are touching are connected (right); the remainders of the surfaces are free to move and deform independently.

Bonds accurately represent simple, permanent connections, such as welds. You can also use a bond to approximately represent simplified connections between two components that are fastened together using other means. For example, if two components are bolted together, you can define a bond between the contacting surfaces around the bolt; the bolt no longer serves a purpose and can be removed from the assembly for the simulation.