An Investigation of the Self-Loosening Behavior of Bolts Under Transverse Vibration

Investigation of the Axial Stiffness of a Bolt Using a Three-Dimensional Finite Element Model

“…Zadoks and Yu [1] analyzed the conditions needed for transversely loaded connections to loosen and stated that the o!-torque in the bolt must overcome all of the frictional resistances for the bolt to loosen. With their experiments on a connection with a single bolt, as shown in Figure 1, they proved that impact is a su$cient condition for the bolt to loosen dynamically.…”

“…Even though considerable research has explored the self-loosening behavior of bolts, the exact mechanisms of this behavior had remained obscure until recent papers by Zadoks and Yu [1] and Hess [2] accurately predicted the self-loosening behavior of a single bolt subject to harmonic base excitations in the transverse and axial directions, respectively (see Figure 1). …”

Characterization of contact condition in a flange connection by longitudinal waves

“…Individual pipes are connected with a flange joint that is composed of two metal disks and a gasket with a low elastic stiffness. In aged pipe systems, leaks occasionally occur because the contact conditions at the joint may deteriorate owing to degradation of the gasket and vibration due to fluid flow and/or cyclic thermal stress (Zadoks et al, 1997). The contact condition may not be uniform because of the misalignment of pipes during construction.…”

An Analytical Model for Rotation Stiffness and Deformation of an Antiloosening Nut under Locking Force

“…Some researches intended to make clear of the phenomenon of self-loosening of bolt based on the vibration theory [4][5][6][7][8][9]. However, the popularly known antiloosening fasteners do not seem to possess much resistance to loosening by the test results [10,11] for the effectiveness of screw threads, spring washers, nylon inserted nuts, double nuts, and eccentric nuts of few sizes to resist loosening.…”