A Review Paper on Looseness Detection Methods in Bolted Structures

Since the looseness is initiated with a reduction in the axial force, measurement and estimation of this force can contribute to a healthy performance of the structure. The methods used to measure axial force of bolts are divided into two: those which measure or estimate the force directly and those which, by controlling physical parameters, do this indirectly. Ba- sed on this categorization, this paper examines over 16 methods used for evaluation of axial force of bolted structures, and presents their theoretical bases, drawbacks and advantages, with the litera- ture on each method being discussed separately.

Finally, the methods are compared and the most important criteria in selecting the methods are introduced.