Q. Internal force of preloaded fasteners?
Force in a bolt in a bolted joint relies on the preloading force applied to it at the time of the tightening operation. For example, when preloaded bolt is tightened with a certain force, bolts' internal force would not increase considerably if the external applied force on bolted joint doesn't exceed the preloading force. It looks like the bolt doesn't feel the external applied force and it's not until the external force has exceeded preloading force when a substantial increase ofinternal force of the bolt will take place.