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The force in a bolt in a bolted joint depends on the preloading force applied to it during the tightening operation. For instance, when the preloaded bolt is tightened with a certain force, the bolts’ internal force will not increase significantly if the external applied force on the bolted joint does not exceed the preloading force.
It looks like the bolt does not feel the external applied force and it is not until the external force has exceeded the preloading force when a substantial increase of internal force of the bolt will occur.
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