A research on tightening characteristics of slotted nut-bolt connection pair

doi:10.16731/j.cnki.1671-3133.2024.06.016

Abstract

Abstract: Since the aircraft is continuously subjected to vibratory loads during flight process,the self-locking slotted nut-bolt connection pair is widely used in design to prevent loosening of the bolt and loss of clamping force.Studying the tightening characteristics of the slotted nut-bolt connection pair is of great significance for ensuring the mechanical performance,safety,and reliability of the connected structure.Theoretical analysis was conducted on the tightening process of the slotted nut,and the clamping force-tightening torque relationship formula was corrected.The influence of factors such as slotted nut type,connected material,lubrication conditions,and repeated tightening times on tightening characteristics was investigated through experiments.The results show that the prevailing torque of NASM14144 slotted nut is increased by 125.9 % and the torque coefficient is slightly decreased compared with the lower NASM14145 slotted nut.Torque coefficient and its fluctuation can be effectively reduced by saturated lubrication method,and lubrication of the nut-plate bonding surface is less effective.In the process of repeated tightening,the prevailing torque of NASM14144 nut was reduced and the torque coefficient was significantly increased,while the tightening characteristics of NASM14145 nut did not change significantly.

Key words: tightening process, slotted nut, prevailing torque, clamping force, composite material

CLC Number:

V229+.1

LI Kun, LIU Longquan. A research on tightening characteristics of slotted nut-bolt connection pair[J]. Modern Manufacturing Engineering, 2024, 525(6): 122-127.

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