Experimental and numerical studies of bolted joints subjected to axial excitation

Liu, Jianhua; Ouyang, Huajiang; Peng, Jinfang; Zhang, Chaoqian; Zhou, Pingyu; Ma, Liang; Zhu, Minhao

doi:10.1016/j.wear.2015.10.012

Cited by 76 publications

(35 citation statements)

References 31 publications

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“…There has been much research on this topic. Self-loosening mechanisms [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] and their various influencing factors [17][18][19][20][21] were studied through experiments, theoretical analyses and numerical simulation. A variety of measures were proposed to prevent self-loosening, such as chemical locking [21], step lock bolt (SLB) [22], and double-nut [8,23].…”

Section: Introductionmentioning

confidence: 99%

“…However, there has not been a universal acceptance regarding the self-loosening process mechanisms. The focus of the early research in the field was on loosening due to axial loading (dynamic loads acting along the fastener axis) [1][2][3][4][5][6]. Goodier et al highlighted the radial sliding motions between the threads of the bolt and the nut or the interfaces of the clamped bearing surfaces as important factors causing loosening of a threaded coupling structure under axial vibration [1].…”

Section: Introductionmentioning

confidence: 99%

“…Nassar and co-workers considered the irreversible plastic deformation of bolts under axial vibration as a major loosening mechanism [4,5]. Additionally, Liu et al found that the plastic deformation of the structure and fretting wear between contact surfaces were the loosening mechanism of bolted joints under axial excitation [6].…”

Section: Introductionmentioning

confidence: 99%

“…The decrease of friction coefficients increases the preload under the same initial tightening torque which leads to a better anti-loosening performance. Liu et al considered adding MoS 2 lubricant to bolted joints as a good method to prevent loosening when the bolted joint was subjected to axial excitation [6]. Hence, it is crucial to investigate the effect of coating on the self-loosening of threaded fasteners.…”

Section: Introductionmentioning

confidence: 99%

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Anti-loosening performance of coatings on fasteners subjected to dynamic shear load

et al. 2017

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This paper investigates the self-loosening of threaded fasteners subjected to dynamic shear load. Three kinds of typical coatings, PTFE, MoS 2 , and TiN applied to bolts and nuts, are tested in this investigation. The study experimentally examines the loosening mechanisms of fasteners and assesses the anti-loosening performance of the three tested coatings based on their tightening characteristics, loosening curves, and the damage of thread surface. Additionally, the anti-loosening performance of the three coatings is compared under different load forms. The results indicate that the PTFE and MoS 2 coatings have significant anti-loosening effect, whereas the anti-loosening performance of TiN coating is not satisfactory. It is also found that an appropriate increase of the initial tightening torque can significantly improve the anti-loosening effect. In addition, the microscopic analyses of PTFE and MoS 2 coating reveal that a reduced initial tightening torque leads to fretting wear on the thread contact surfaces of fasteners, thereby aggravating the damage.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Anti-loosening performance of coatings on fasteners subjected to dynamic shear load

et al. 2017

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“…5 Naser, 6 Musto and Konkle, 7 Nawras, 8 and Naser and Abbound 9 also proposed mathematical expressions for the bolted-joint stiffness. In addition, Qin et al 10 and Liu et al 11 researched the dynamic behavior of bolted joints. Nearly all of these studies are limited to estimate the stiffness of bolted joint as a fixed unit without any consideration of engaged threaded deformation.…”

Section: Introductionmentioning

confidence: 99%

A new computational method for threaded connection stiffness

Zhang

Gao

2016

Advances in Mechanical Engineering

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For designing bolted connections in machinery applications, it is necessary to estimate the stiffness of the threaded connection. This work provides a new method for computing the stiffness of engaged screw in bolted connections according to the load distribution in screw thread. Finite element analysis is performed by building the three-dimensional model of threaded connection. A set of tensile tests are exerted to validate the accuracy of the suggested model of threaded connection. A good agreement is obtained when the analytical results are compared with finite element analysis results, experimental data, and Yamamoto method. Results reveal that the ultimate strength of thread connections is obviously lower than that of thread material. In addition, the results of calculation and finite element analysis indicated that increasing Young's modulus of material and the engaged length or decreasing thread pitch could increase the stiffness of the thread portion of a bolt and nut.

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01.18: Optimization of the pre‐loading procedure for high‐strength bolts of FREEDAM connections

et al. 2017

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A FREE from DAMage (FREEDAM) friction connection is a particular type of sliding hinge joint where in correspondence of the lower beam flange is realized a friction damper with steel angles and coated plates, pre-stressed with high strength bolts. In order to master the resistance of a FREEDAM connection it is crucial to know accurately the value of the friction coefficient of the materials employed to realize the damper and to control the preload applied to the friction interface by means of high strength bolts. Dealing with this last topic, according to Eurocode 3 and EN 1090-2, High Strength bolts (both of HR or HV type), when installed in friction bearing connections, must be installed based on one of four proposed procedures. The methods currently recommended are torque, combined, HRC and DTI and each of them, as already partially reported in technical literature, can lead to a different level of accuracy. Additionally, once the bolt is tightened it is well known that it undergoes to an "instantaneous" (short-term relaxation) and to a "long-term" loosening that, obviously, may affect the response of the FREEDAM connection which has to be designed not to slip under service loading conditions. Within this framework, the goals of the paper are multiple. First of all, by means of experimental analysis, it is wanted to assess the accuracy of some of the codified tightening methods, namely torque and combined, when applied to FREEDAM connections. Additionally, the possible bolts' loosening occurring in short/medium periods of time (up to one month) are evaluated performing specific tightening tests. Finally, the effectiveness of Belleville spring washers in keeping the pre-loading constant during the life-time of the FREEDAM connection is assessed. In order to analyse all these aspects, an experimental analysis carried out at the STRENGTH laboratory of the University of Salerno, regarding 84 tightening tests performed on specimens of friction dampers is presented. All the specimens have been tested measuring with annular load cells the initial force applied to the bolts in order to evaluate the achievement of the target preload. Additionally, in some cases, the loss of pre-load over a period of time has been monitored.

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Experimental and numerical studies of bolted joints subjected to axial excitation

Cited by 76 publications

References 31 publications

Anti-loosening performance of coatings on fasteners subjected to dynamic shear load

Anti-loosening performance of coatings on fasteners subjected to dynamic shear load

A new computational method for threaded connection stiffness

01.18: Optimization of the pre‐loading procedure for high‐strength bolts of FREEDAM connections

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