EFFECT OF NON-PARALLEL WEDGED SURFACE CONTACT ON LOOSENING PERFORMANCE OF PRELOADED BOLTS UNDER TRANSVERSE EXCITATION

An analytical model is proposed for investigating the effect of non-parallel (wedge) contact on the loosening performance of a preloaded bolt-nut connection under transverse cyclic excitation along the wedge direction. From the model, if the wedge angle is sufficiently small, the self-loosening may take place. On the other hand, if the wedge angle is large enough, the self-loosening caused by the back off rotation may be prevented. Experimental and analytical results show that the proposed model accurately predicts both the self-loosening performance, and it also establishes the requirements for preventing the loosening of the preloaded bolt-nut system. 1