When designing a slip-critical bolted connection, what is the primary mechanism by which the connection transfers shear forces, and why is this mechanism different from a bearing-type connection?

When designing a slip-critical bolted connection, the primary mechanism by which the connection transfers shear forces is friction. Shear forces are forces that act parallel to the surface of a material, tending to cause one part of the material to slide past another. In a slip-critical connection, high-strength bolts are installed and tightened to a specified tension, known as pretension. This pretension creates a significant clamping force that presses the connected elements, or plates, tightly together. The surfaces in contact, called the faying surfaces, are designed to have a high coefficient of friction, often achieved through surface preparation like grit blasting. This high clamping force, combined with the friction between the faying surfaces, generates a substantial friction resistance that prevents any relative movement, or 'slip', between the connected parts when subjected to shear forces. The connection is designed to resist the applied shear load entirely through this friction wi....