Identification of Pre-Tightening Torque Dependent Parameters for Empirical Modeling of Bolted Joints

Tian, Yu; Qian, Hui; Cao, Zhifu; Zhang, Dahai; Jiang, Dong

doi:10.3390/app11199134

Cited by 9 publications

(10 citation statements)

References 29 publications

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“…It should be stated that in reality, the size of this angle (see Figure 5) can differ. Moreover, this angle is very important from a technical point of view and also serves as a basis for new calculation methodologies, e.g., see [5]. However, this issue will be described in more detail in Section 3.…”

Section: Description Of the Basic Approach To Solving Bolted Jointsmentioning

confidence: 99%

“…In the following, the study of literature sources focused on existing theoretical calculation procedures, which are presented, e.g., in [3] and [4]. Attention was also given to new methods of calculations as reported by Y. Tian [5]. Previous research on the effect of the asymmetry of a multi-bolted connection on the asymmetry of the connected pressure vessel shell has also provided an important basis for solving the problem, see [6].…”

Section: Introductionmentioning

confidence: 99%

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Influence of Symmetry of Tightened Parts on the Force in a Bolted Joint

et al. 2023

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This article discusses the issue of force behavior in a pre-tensioned bolt that is part of a symmetrical flange connection, loaded with an operating load parallel to the bolt axis. The first part describes the issue being dealt with in detail. The next part offers a brief description of the generally known theoretical approach to the solution, and also outlines the limitations of this approach. This part is followed by a theoretical analysis of working load behavior in the bolt of the analyzed device, using Finite Element Method (FEM). In this article, a comparison of several different approaches to the solution can be also found, followed by a description of the experiment preparation and its results. The obtained values also serve as a subject for reverse iterative analysis carried out using ANSYS software. The aim is to find a proper modification to the symmetric calculation model that would be consistent with the results of measurements from technical practice. All results achieved are described in the final part of the article.

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Section: Description Of the Basic Approach To Solving Bolted Jointsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influence of Symmetry of Tightened Parts on the Force in a Bolted Joint

et al. 2023

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“…Finally, the nut rotation angle measured by the protractor is compared and analyzed with the detection value of YOLOv5; analysis of the experimental data is shown in Table 3. The error of bolt loosening angle is calculated by Equation (6).…”

Section: Identification Of Bolt Loosening At Any Anglementioning

confidence: 99%

“…The mechanical performance of the bolted connection is related to pretightening torque, thread pair contaction and friction of contact surfaces [ 6 , 7 , 8 ]. In order to explore the mechanism of bolt loosening, Goodier et al [ 9 ] tested the behavior of bolted connections under dynamic load.…”

Section: Introductionmentioning

confidence: 99%

Vision-Based Detection of Bolt Loosening Using YOLOv5

Sun

Dong

et al. 2022

Sensors

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Bolted connections have been widely applied in engineering structures, loosening will happen when bolted connections are subjected to continuous cyclic load, and a significant rotation between the nut and the bolt can be observed. Combining deep learning with machine vision, a bolt loosening detection method based on the fifth version of You Only Look Once (YOLOv5) is proposed, and the rotation of the nut is identified to detect the bolt loosening. Two different circular markers are added to the bolt and the nut separately, and then YOLOv5 is used to identify the circular markers, and the rotation angle of the nut against the bolt is calculated according to the center coordinate of each predicted box. A bolted connection structure is adopted to illustrate the effectiveness of the method. First, 200 images containing bolts and circular markers are collected to make the dataset, which is divided into a training set, verification set and test set. Second, YOLOv5 is used to train the model; the precision rate and recall rate are respectively 99.8% and 100%. Finally, the robustness of the proposed method in different shooting environments is verified by changing the shooting distance, shooting angle and light condition. When using this method to detect the bolt loosening angle, the minimum identifiable angle is 1°, and the maximum detection error is 5.91% when the camera is tilted 45°. The experimental results show that the proposed method can detect the loosening angle of the bolted connection with high accuracy; especially, the tiny angle of bolt loosening can be identified. Even under some difficult shooting conditions, the method still works. The early stage of bolt loosening can be detected by measuring the rotation angle of the nut against the bolt.

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“…At present, domestic and foreign scholars have done a lot of research on the theory of pipe joints and contact mechanics in the aviation hydraulic system, and found that the flarefree connection structure has the advantages of convenient connection, repeatable disassembly and assembly, good sealing performance, and so on. [1] Tian et al [2] proposed a method to determine the stiffness parameters related to the pretightening moment, which could obtain all parameters of equivalent thinlayer elements within a certain range of pretightening moment. Zheng et al [3] conducted repeatability experiments on threaded fasteners in the tightening process and found that the preload force and its loss had a large dispersion.…”

Section: Introductionmentioning

confidence: 99%

Study on tightening characteristics of flareless pipe joint assembly process

Tang

Liao

Yang

et al. 2023

The Journal of Engineering

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The assembly process of flareless pipe joints is very important for the sealing performance of hydraulic pipeline system. Based on the theory of contact mechanics, a theoretical model of the assembly process of pipe joints is established to simulate the extrusion moulding process of flareless pipe joints. It is found that tightening torque is an important factor affecting the sealing performance of pipe joints. By comparing the changes of the contact stress between the sleeve and the pipe joint under different tightening tortures, combined with the mechanical transfer and deformation results of the contact surface, the results show that the fitting situation of the sleeve and the pipe is good when the expansion pressure is 180 MPa, and the sealing performance of the pipe joint is good when the tightening tortures are between 15 and 18 N⋅m. Considering that the contact surface is a clearance fit, the mean value error of contact stress obtained by simulation verifies that the accuracy of the torsional relationship formula is very high.

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Identification of Pre-Tightening Torque Dependent Parameters for Empirical Modeling of Bolted Joints

Cited by 9 publications

References 29 publications

Influence of Symmetry of Tightened Parts on the Force in a Bolted Joint

Influence of Symmetry of Tightened Parts on the Force in a Bolted Joint

Vision-Based Detection of Bolt Loosening Using YOLOv5

Study on tightening characteristics of flareless pipe joint assembly process

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