Citation

Hou J, Li C, Zhao N, Zhang D, Du C. China Saf. Sci. J. 2022; 32(11): 55-64.

Copyright

(Copyright © 2022, China Occupational Safety and Health Association, Publisher Gai Xue bao)

DOI

10.16265/j.cnki.issn1003-3033.2022.11.1462

PMID

unavailable

Abstract

In order to effectively improve the pre-tightening force of prestressed thread steel bolt and reduce the anchor bolt broken anchor loss phenomenon, the transformation relationship between bolt torque and pre-tightening force and the dangerous points of a bolt in the nut assembly process were analyzed theoretically. The factors affecting pre-tightening force and the causes of bolt fracture were obtained. The bolt torque-pre-tightening force conversion test tooling was developed. The bolt pre-tightening process applied to the total torque, thread pair torque, and tray bearing surface torque were detected, respectively. The rolling friction-reducing gasket of the anchor rod was developed. Through theoretical analysis and field application, the relationship between torque and preload was obtained, and the influence of friction loss of pallets on preload was reduced. The tension-compression separation nut was developed. The force cloud diagram and torque-preload transformation relationship were obtained through numerical simulation and laboratory tests, and the influence of thread pair deformation and poor stress environment on preload was reduced. The results show that the rolling friction-reducing gasket can reduce the friction between the nut and the supporting surface of the tray, improve the torque-preload conversion efficiency, and increase the preload by more than two times. By applying the tension-compression separation nut, the concentrated load bearing of the tension-compression composite of the traditional bolt thread pair is optimized to the uniform load bearing of the tension-compression separation type, which significantly alleviates the stress of the dangerous surface and dangerous point of the bolt, realizes the coordinated deformation of the thread pair, and reduces the phenomenon of broken anchor. © 2022 China Safety Science Journal. All rights reserved.

Language: zh