Journal articles on the topic 'Bolt tension'
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1
Guo, Tie Neng, Gen Li, Li Gang Cai, and Zhi Liang Wang. "The Study of High Strength Bolt Preload with Hydraulic Tensioner Installation." Advanced Materials Research 314-316 (August 2011): 988–94. http://dx.doi.org/10.4028/www.scientific.net/amr.314-316.988.
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Preloading the high strength bolt using hydraulic extension method is a fast and efficient method for bolt installation. Hydraulic bolt tension device can guarantee the initial tension of bolt well. However, if the relation of initial tension and the final remaining preload of bolt cannot be determined, the preload on the bolts still cannot be guaranteed. This paper uses theoretical analysis method to research the relation between the eventual preload and the initial tension of high strength bolts on Heavy-duty Gantry beams. Then we proposes a set of calculation method of bolt installation preload and the initial tension and provides theoretical basis for the installation of heavy-duty segmented beam.
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Lee, Seung Yong, Cheol Woo Park, Soon Cheol Kwon, and Hee Hyun Lee. "Mechanical Behavior of High-Tension Bolted Joints with Varying Bolt Size and Plate Thickness." Key Engineering Materials 348-349 (September 2007): 81–84. http://dx.doi.org/10.4028/www.scientific.net/kem.348-349.81.
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The use of steel plates has been greatly increased in bridge construction, particularly for long-span bridges, and connections between the plates are made usually using high-tension bolts. However, the specifications on the use of large-sized high-tension bolts are not adequately stated in the currently available construction manuals. In order to provide further information on the use of the large-sized high-tension bolts, this study experimentally investigated the relaxation and slip behavior of M30 bolts with varying bolt size and plate thickness. In addition, numerical evaluation using FEM was performed to investigate the compressive stress occurred on the inside of bolt hole. The analyzed results were compared with the stress distribution measured from strain gages attached on the bolts and bolt holes. From the study presented herein, it was found that the relaxation was increased as the size of bolt increased, and that the M30 high-tension bolts developed slip coefficient greater than 0.4. The thickness of plate did not significantly affect the compressive stress distribution around the bolt holes.
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Sun, Qingchao, Qingyuan Lin, Bin Yang, Xianlian Zhang, and Lintao Wang. "Mechanism and quantitative evaluation model of slip-induced loosening for bolted joints." Assembly Automation 40, no. 4 (April 3, 2020): 577–88. http://dx.doi.org/10.1108/aa-08-2019-0152.
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Purpose Bolted joints are the most common type of mechanical connections, and improving the anti-loosening performance of bolts for the reliable performance of mechanical and building structures is highly significant. Design/methodology/approach Because of the lack of sufficient theoretical basis for the evaluation and design of anti-loosening bolts, a quantitative evaluation model exhibiting the following two evaluation criteria for anti-loosening bolts is introduced: bolt rotation angular acceleration criterion and critical transverse load criterion. Based on the relationship among bolt tension, transverse load and bolt rotation angular acceleration, a critical transverse load calculation model is put forward, and the mechanism by which the critical transverse load increases with the increase of bolt tension is revealed. Findings Based on the above model, a new type of anti-loosening bolt is designed, which generates additional bolt tension when the transverse load increases, and then improves the critical transverse load of the bolt. The effectiveness of the new type of anti-loosening bolt is verified by theoretical calculations and experiments. Originality/value The proposed model and method set a preliminary theoretical foundation for the evaluation of bolt anti-loosening performance and the design of a new anti-loosening bolt.
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Plaitano, Francesco, Aurel Stratan, and Elide Nastri. "Simplified Modelling of Failure in High Strength Bolts under Combined Tension and Bending." Journal of Composites Science 6, no. 10 (October 11, 2022): 302. http://dx.doi.org/10.3390/jcs6100302.
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Bolted connections are widely adopted in steel structures and their behaviour affects to a large extent the global response of the system. High-strength bolts of type HV are commonly employed. Under pure tension, these bolt assemblies usually fail by thread stripping. However, it was observed experimentally that, under combined tension and bending, the failure mode changes to fracture of the shank. The former loading condition commonly occurs in the case of thick extended end plate connections and the latter in the case of flush end plates. In order to analyse the behaviour of the structure, the finite element method (FEM) is usually employed. While there is a wealth of information on FEM modelling of bolts for standard loading conditions (e.g., tension), the authors are unaware of a model able to replicate both tension-only and combined tension and bending conditions. In this paper, a simplified approach to be used in the framework of FEM is proposed to model the behaviour of high-strength HV bolts which can replicate the failure mechanism of bolts under tension only and combined tension and bending. The bolt assembly is modelled with continuum elements, supplemented by a non-linear spring connecting the nut to the bolt shank. The spring captures the stiffness, resistance, and ductility of the bolt-to-nut threaded connection, reproducing the experimentally observed failure mode in the case of pure tension conditions. A simplified damage model is applied to the continuum finite elements used to model the bolt, which replicates shank failure under combined tension and bending as a result of large local stresses and strains occurring under these conditions. The proposed model captures with good accuracy the actual behaviour of high-strength HV bolts under tension only as well as under combined tension and bending.
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Alhazmi and Guldiken. "Quantification of Bolt Tension by Surface Acoustic Waves: An Experimentally Verified Simulation Study." Acoustics 1, no. 4 (September 27, 2019): 794–807. http://dx.doi.org/10.3390/acoustics1040046.
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Quantifying bolt tension and ensuring that bolts are appropriately tightened for large-scale civil infrastructures are crucial. This study investigated the feasibility of employing the surface acoustic wave (SAW) for quantifying the bolt tension via finite element modeling. The central hypothesis is that the real area of contact in a bolted joint increases as the tension or preload is increased, causing an acoustical signature change. The experimentally verified 3-D simulations were carried out in two steps: A preload was first applied to the bolt body to simulate the realistic behavior of bolted joint; and the SAW propagation was then excited on the top surface of the plate to reflect from the bolted joint. The bolt tension value was varied between 4 and 24 kN (properly tightened bolt) in the steps of 4 kN to study the effect of the bolt tension. The results indicate an increased reflected wave amplitude and a gradual phase shift, up to 0.5 µs, as the bolt tension increased. Furthermore, the result shows that the distance between the first reflected wave and the source becomes shorter as the preload increases, as hypothesized. A 1.9 mm difference in the distance between the maximum and minimum preload was observed. As part of this study, the simulation results were also compared with the experimental results, and a good agreement between the simulation and experiments was demonstrated.
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Cheng, Peng, Jian Zhang, and Ai Qing Liu. "Mechanism Analysis of Anchor Bolt and Cable Synergistic Action in Coal Roadway Support." Applied Mechanics and Materials 716-717 (December 2014): 735–38. http://dx.doi.org/10.4028/www.scientific.net/amm.716-717.735.
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Aiming at the current situation of anchor bolt and cable arrangement in mine roadway support, the paper analysis the mechanical characteristics and mechanism of bolts and cables, and numerical simulation method is used to comparison and analysis of pre-tension distribution characteristics under different anchor bolt-cable arrangement. The research indicated that separate anchor bolt-cable layout in different sections, anchor bolt and cable force stable equilibrium, coordinate with each other, at this time roadway surrounding rock of shallow and deep pretension distribution more reasonable, can play a role of bolt anchor cable synergistic action, and form the best pre-tension load-bearing structure, which is helpful to keep the stability of coal roadway.
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Kim, Jin Sung, Hoon Huh, Won Mog Choi, and Tae Soo Kwon. "Crash Tests of Tension Bolts in Light Safety Collision Devices." Key Engineering Materials 385-387 (July 2008): 685–88. http://dx.doi.org/10.4028/www.scientific.net/kem.385-387.685.
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This paper demonstrates the jig set for the crash test and the crash test results of the tension bolts with respect to an applied pre-tension. The tension and shear bolts are adopted at Light Collision Safety Devices as a mechanical fuse when tension bolts reach designed failure load. The kinetic energy due to the crash is absorbed by secondary energy absorbing devices after the fracture of tension bolts. One tension bolt was designed to be failed at the load of 375 kN. The jig set was designed to convert a compressive loading to a tensile loading and installed at the high speed crash tester. The strain gauges were attached at the parallel section of the tension bolts to measure the level of the pre-tension acting on the tension bolts. Crash tests were performed with a barrier whose mass was 250 kg and initial speed of the barrier was 9.5 m/sec. The result includes the load response of the tension bolts during both the crash tests and finite element analysis.
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Wang, Rui, Jian-biao Bai, Shuai Yan, Yuan-ba Song, and Guang-dong Wang. "An Improved Numerical Simulation Approach for the Failure of Rock Bolts Subjected to Tensile Load in Deep Roadway." Geofluids 2020 (October 10, 2020): 1–21. http://dx.doi.org/10.1155/2020/8888390.
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Our goal was to develop an effective research tool for roadways with significant deformations supported by rock bolts. The improved numerical simulation approach is constructed through additional development of FLAC3D. The aim is to modify the shortcoming that the original model in FLAC3D regards the plastic tensile strain of any arbitrary rock bolt element node as the rupture discrimination criterion. The FISH programming language is adopted to conduct the secondary development and to embed the revised model into the main program of FLAC3D. Taking an actual mining roadway as the simulation object, two simulation schemes adopting the newly improved approach and the original method were conducted, respectively. The results show that (1) the PILE element that constitutes the rock bolt-free section with the maximum elongation rate ruptures after modification, while the rock bolt tendon elongation rate reaches beyond the predefined tensile rupture elongation rate; (2) the modified model in which the rock bolt is mainly subjected to tension realises the tensile rupture phenomenon at the end of the rock bolt-free section and the rock bolt at the junction between the free section and the anchoring section; and (3) only four rock bolts that are in the roadway sides showed rupture in the modified model, and all rock bolts showed rupture in the original model. The tensile failure of the rock bolt led that the modified model scheme is closer to the actual. Compared with the modified model, in the original model, deformation of the surrounding rock masses is severe. This is resulted by the rupture of all rock bolts in the original model. The analysis shows that the improved numerical simulation approach is much more reliable for large deformation roadway behavior with rock bolt support.
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Li, Ya Na, Chun Yan Wang, Yong Ming Li, Ben Teng Rao, and Lin Zhang. "Strength Calculation Based on Contact Nonlinear Analysis of Coupler Bolt with Three Methods." Advanced Materials Research 1006-1007 (August 2014): 66–70. http://dx.doi.org/10.4028/www.scientific.net/amr.1006-1007.66.
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Bolts as the key connection parts are directly related to the safety of high-speed train. Contact nonlinear static strength of CRH (China Railway High-Speed) coupler bolt was analyzed on traction and compression load with ANSYS software. According to maximum stress of bolts was appeared on tension load, CRH bolt strength was evaluated and compared based on three methods: finite element analysis (FEA), "Verein Deutscher Ingenieure 2230 standard (VDI 2230)" and “Mechanical Design Handbook”. The results show that the axial tensile stress is much greater than the shear stress and gradually increase with three methods.
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Zhao, Yiming, Nong Zhang, Guangyao Si, and Xuehua Li. "Study on the Optimal Groove Shape and Glue Material for Fiber Bragg Grating Measuring Bolts." Sensors 18, no. 6 (June 2, 2018): 1799. http://dx.doi.org/10.3390/s18061799.
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Fiber Bragg grating (FBG) measuring bolts, as a useful tool to evaluate the behaviors of steel bolts in underground engineering, can be manufactured by gluing the FBG sensors inside the grooves, which are usually symmetrical cuts along the steel bolt rod. The selection of the cut shape and the glue types could perceivably affect the final supporting strength of the bolts. Unfortunately, the impact of cut shape and glue type on bolting strength is not yet clear. In this study, based on direct tension tests, full tensile load–displacement curves of rock bolts with different groove shapes were obtained and analyzed. The effects of groove shape on the bolt strength were discussed, and the stress redistribution in the cross-section of a rock bolt with different grooves was simulated using ANSYS. The results indicated that the trapezoidal groove is best for manufacturing the FBG bolt due to its low reduction of supporting strength. Four types of glues commonly used for the FBG sensors were assessed by conducting tensile tests on the mechanical testing and simulation system and the static and dynamic optical interrogators system. Using linear regression analysis, the relationship between the reflected wavelength of FBG sensors and tensile load was obtained. Practical recommendations for glue selection in engineering practice are also provided.
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Hyde, T. H., L. V. Lewis, and H. Fessler. "Bolting and loss of contact between cylindrical flat-flanged joints without gaskets." Journal of Strain Analysis for Engineering Design 23, no. 1 (January 1, 1988): 1–8. http://dx.doi.org/10.1243/03093247v231001.
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Four bolts of a lightweight, steel, flanged joint were strain-gauged to measure bolt tension and bending. Three-dimensional, finite element analysis was used to determine bolt strains and gaps between the flanges due to axial tension and internal pressure for three different contact conditions. Two joints were tested. The front faces of the first joint were nominally flat while the second had a small negative cone angle (⋍ 0 degrees 15 minutes) so that flanges initially touched at the outside only. The non-linearity of experimental bolt strain with external load shows that the contact area around the bolts decreases with increasing axial tension. Comparison with the finite element predictions shows the rate at which the contact area diminishes. The finite element results also demonstrate that flange deflection is underestimated when contact area loss is ignored, and the consequences for leakage prediction are explained.
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Sastry, S. S. Subramanya, Sivanagaraju Reddy, and K. Naresh Babu. "EXPERIMENTAL AND NUMERICAL STUDIES ON MULTI-BOLT DOUBLE COVER BUTT JOINTED GLASS FIBRE REINFORCED COMPOSITE LAMINATES WITH ALUMINIUM BUTT STRAPS." International Journal of Engineering Technologies and Management Research 6, no. 5 (March 25, 2020): 1–40. http://dx.doi.org/10.29121/ijetmr.v6.i5.2019.370.
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Numerical and experimental studies on multi-bolt double cover butt jointed glass fibre reinforced composite laminates with Aluminium butt straps (size 270 x 72 x 3/4/5 mm) subjected to a tensile load are presented. Experiments were conducted using the assembled specimens in Instron testing machine under uniaxial load. The test specimens exhibited bearing failure of the laminate at all bolt points followed by net tension failure along the line of bolts close to the grips. Investigation are conducted to study the effects of material composition, consistency of fabrication, bearing-bypass interaction / damage onset, specimen thickness on the stress-strain behaviour of the specimen, load distribution in bolts, types of fit and friction, material anisotropy and contact condition under bolt preload. Influence of these parameters on the contact stresses around the bolt and stresses in the butt straps are discussed. Finite element analysis was carried out using ANSYS for various parameters and results were compared with test data.
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Shi, Gang, Hao Fan, Yong Jiu Shi, and Yuan Qing Wang. "Finite Element Analysis of High-Type Large Capacity End-Plate Connections." Applied Mechanics and Materials 71-78 (July 2011): 3673–79. http://dx.doi.org/10.4028/www.scientific.net/amm.71-78.3673.
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Compared to the traditional configurations, beam-column end-plate connections with two bolt rows located at the external side of the beam tension flange, i.e. high-type large capacity end-plate connections, could stand greater loading. However, seldom research on the static behavior of high-type end-plate connections has been done in China while specification in America has provided corresponding design approaches. In this paper, detailed verified finite element model will be employed to analyze the static behavior of 7 high-type end-plate connections with different configurations. The influence of parameters such as end-plate thickness, bolt layout, end-plate configuration and stiffener geometry has been investigated. The simulation results demonstrate that (1) when the maximum transferred tension force by a single bolt reaches 0.8P, the tension force of the bolts does not satisfy the assumption of linear distribution but depends on the boundary conditions of the bolts; (2) the shear force in the connection is transferred by the contact surface of the end plate and the shear force directly transferred by the bolts is tiny and extremely uneven; (3) considering the effect of the connection configurations, whether the end plate at the compression side is extended or not has little effect on the static behavior of the connection but the geometry of the end-plate stiffener and the distance from the bolt axis to the beam web have great contribution to the initial stiffness of the connection; (4) at ultimate state even the bolts located near the beam axis have significant contribution to the loading capacity of the connection. Then, a model of the bolt transferred tension force distribution has been proposed. What’s more, based on the observation of the stress contour of the tension part of the end plate, a yield line model has been proposed. All these results are important to propose a design approach for the high-type end-plate connection. Introduction
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Couchaux, Maël, Mario D’Aniello, Lucia Falciano, Beatrice Faggiano, Mohammed Hjiaj, and Raffaele Landolfo. "Finite Element Simulations on the Tensile Resistance of Bolted End-Plate Connections with Tubular Members." Open Construction and Building Technology Journal 12, no. 1 (May 23, 2018): 177–86. http://dx.doi.org/10.2174/1874836801812010177.
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Background: Bolted end-plate connections represent the simplest and cheapest way to connect tubular members. EN1993:1-8 provides the general rules based on component method. However, in the case of splices with tubular members the proper definition of the effective length around corner bolts is not clearly addressed. Objective: The objective of the study is to investigate the accuracy and the effectiveness of the existing analytical predictions to estimate the tensile resistance of end-plate connections with tubular members where corner bolts are adopted. Method: Parametric finite element analyses were carried out to investigate the tensile strength of connections of both square and rectangular hollow sections. Results: The tension resistance is largely influenced by the corner bolts. Indeed, the connections with corner bolts exhibit larger resistance that increases when the bolts are closer to the corner of the tubular member. However, reducing the distance between the bolt and the wall of the tubular section can affect the splice ductility. Conclusion: • The method proposed Steige and Weynand to calculate the tension resistance of connections with bolts distributed on all sides of the splice is consistent with EN 1993-1-8. • The finite element simulations showed that the corner bolts can increase the resistance of the connection. In addition, the bolt layout can be optimised by placing the bolts as close to the hollow section as possible.
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Dong, Zheng Yan, and Han Long Zhang. "Bolt Static Finite Element Numerical Simulation and Experimental Research." Applied Mechanics and Materials 494-495 (February 2014): 373–76. http://dx.doi.org/10.4028/www.scientific.net/amm.494-495.373.
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This study investigated the wind turbine blade root bolt static strength using the full scale static test, selected the root bolts of 1/4 bridge strain gauge using the finite element analysis method and the dynamic and static strain instrument. The data of the stress loading combined tension and bending bolt were obtained.
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Zhang, Peng Bo, Zhi Xiang Yu, Yu Ping Sun, and Shi Chun Zhao. "Effect of Lap Gap on the Frictional Performance of Shear-Type Friction Damper." Advanced Materials Research 374-377 (October 2011): 2513–19. http://dx.doi.org/10.4028/www.scientific.net/amr.374-377.2513.
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The shear-type friction damper using aluminum alloy as the friction material were designed and tested under cyclical loading to investigate the effect of the lap gap to the frictional performance. The test results indicated that the dampers with a lap gap could also absorb energy stably with the same hysteretic behavior as a general friction damper; the frictional force of the shear-type friction damper depended not only upon the bolts tension by the high-strength bolts that clamped the sliding steel plate but also strongly upon the scale of lap gap. The lap gap changed in a scale of 0.12mm only, the average sliding force has four times increase at a lower level of bolt tension, and a double effect to increasing sliding force at the higher level of bolt tension.
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Hatami, Mandi, Gregory A. MacRae, Geoffrey W. Rodgers, and George Charles Clifton. "Numerical Study of Asymmetric Friction Connections (AFC) with Large Grip Length Bolts." Key Engineering Materials 763 (February 2018): 600–608. http://dx.doi.org/10.4028/www.scientific.net/kem.763.600.
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A Finite Element (FE) model is used to simulate the experimental behaviour of high strength bolts in asymmetric friction connections (AFC). Two M16 connections tested previously are modelled using ABAQUS and are subjected to cyclic lateral displacements. The numerical results were similar to that from previous experimental studies. It was also shown that hysteresis loop strength and stability reduced for longer bolt grip lengths. Other information, which cannot be easily monitored in experimental tests, such as the bearing stress distribution between plates, component equivalent plastic strain, and bolt tension force, were obtained at different sliding distances. It was shown that bolt and plate plastic deformation tended to occur in bolts with a long grip length to bolt diameter ratio.
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Wang, Yong, Hao Wang, Jue Hui Xu, Shu Xun Zhang, Zhao Ping Feng, and Yan Song. "Bearing Capacity Reduction Factor of High Strength Bolts in the Application of Steel Grid Structures." Applied Mechanics and Materials 638-640 (September 2014): 309–12. http://dx.doi.org/10.4028/www.scientific.net/amm.638-640.309.
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As a important tension member, high strength bolts having crucial effect for bearing capacity of grid structure. Especially for in-service engineering, when high strength bolt tensile load doesn’t meet the standard requirements, how to determine the structure bearing capacity influence is particularly important. The article is aimed at the situation of the design review and analysis, through the bearing capacity reduction, reducing the high strength bolt bearing capacity, and the reduction of bearing capacity and the actual force are compared, to determine the safety of the structure. Through the question processing, provides a discussion for solving the similar problems.
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TANNO, Yohei, Tomohiro NARUSE, and Taiji HASHIMOTO. "S113035 Estimation of Bolt Tension Decreasing for Bolt Tensioner." Proceedings of Mechanical Engineering Congress, Japan 2013 (2013): _S113035–1—_S113035–5. http://dx.doi.org/10.1299/jsmemecj.2013._s113035-1.
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Miao, Rusong, Ruili Shen, Songhan Zhang, and Songling Xue. "A Review of Bolt Tightening Force Measurement and Loosening Detection." Sensors 20, no. 11 (June 2, 2020): 3165. http://dx.doi.org/10.3390/s20113165.
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Pre-stressed bolted joints are widely used in civil structures and industries. The tightening force of a bolt is crucial to the reliability of the joint connection. Loosening or over-tightening of a bolt may lead to connectors slipping or bolt strength failure, which are both harmful to the main structure. In most practical cases it is extremely difficult, even impossible, to install the bolts to ensure there is a precise tension force during the construction phase. Furthermore, it is inevitable that the bolts will loosen due to long-term usage under high stress. The identification of bolt tension is therefore of great significance for monitoring the health of existing structures. This paper reviews state-of-the-art research on bolt tightening force measurement and loosening detection, including fundamental theories, algorithms, experimental set-ups, and practical applications. In general, methods based on the acoustoelastic principle are capable of calculating the value of bolt axial stress if both the time of incident wave and reflected wave can be clearly recognized. The relevant commercial instrument has been developed and its algorithm will be briefly introduced. Methods based on contact dynamic phenomena such as wave energy attenuation, high-order harmonics, sidebands, and impedance, are able to correlate interface stiffness and the clamping force of bolted joints with respective dynamic indicators. Therefore, they are able to detect or quantify bolt tightness. The related technologies will be reviewed in detail. Potential challenges and research trends will also be discussed.
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Xu, Rongchao, and Hui Zhou. "Experimental Investigation of the Anchoring Effect of Two Different Types of Rock Bolts on Fractured Rock." Advances in Materials Science and Engineering 2019 (February 19, 2019): 1–10. http://dx.doi.org/10.1155/2019/9290318.
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A deep understanding of the anchoring effect of rock bolts on fractured rock is essential for support design in rock engineering. In this paper, cubic specimens containing a single preexisting flaw with different inclination angles were made by high-strength gypsum; uniaxial compression tests were conducted on bolted and unbolted specimens to study the anchoring effect of the fully bonded bolt and the prestressed bolt on fractured rock. The mechanical parameters and failure characteristics of bolted and unbolted specimens were compared and analyzed in detail. The results indicated that both the prestressed and fully bonded bolt had a significant influence on the mechanical behavior of fractured rock. The average value of E, σi, σp, and σr of bolted specimens all increased due to the effect of the rock bolt. The increase degree was the greatest for the specimens with flaw inclination angle of 45°. The increase in residual strength, σr, was the most significant among all the mechanical parameters. The mechanical parameters of specimens anchored with a prestressed bolt increased with an increase in pretension stress. Besides, the reinforcement effect of the two types of rock bolts was different for different mechanical parameters. The bolted specimens displayed different failure characteristics compared to the unbolted specimens. Variation of tension stress in the prestressed bolt during the loading process was divided into three different stages. With an increase in the inclination angle from 30° to 60°, the peak tension stress value first increased and then decreased and obtained the maximum value at inclination angle of 45°. Besides, the peak tension stress value increased with pretension stress.
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Jhang, Kyung Young, Hai Hua Quan, Job Ha, and Noh Yu Kim. "Ultrasonic Estimation of Clamping Force in High-Tension Bolts." Key Engineering Materials 321-323 (October 2006): 240–43. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.240.
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High-tension bolts have been used widely for the clamping of many kinds of large structures. In these bolts, the estimation of clamping force has been regarded as the main issue in the evaluation of clamping condition. This paper proposes a method using ultrasonic wave, which is based on the dependency of sound speed on the stress. In order to verify the usefulness of the proposed method, two kinds of experiments are carried out. The first one involves the measurement of sound speed when the bolt is stressed by the tension tester, and here, the relationship between the exact axial force and sound speed is calibrated. The result shows good agreement with the expected linear relationship between sound speed and axial stress. The second experiment involves the measurement of axial stress by the proposed method when the bolt is stressed by the torque wrench. The results are coincident to the strain gage measurement. From these results, we can conclude that the proposed method is indeed useful in evaluating clamping force in high-tension bolts.
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Wong, Henry, Didier Subrin, and Daniel Dias. "Convergenceconfinement analysis of a bolt-supported tunnel using the homogenization method." Canadian Geotechnical Journal 43, no. 5 (May 1, 2006): 462–83. http://dx.doi.org/10.1139/t06-016.
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The behaviour of tunnels reinforced with radially disposed fully grouted bolts is investigated in this paper. Perfect bonding and ideal diffusion of bolt tension are assumed, so that the bolt tension can be assimilated to an equivalent uniaxial stress tensor. An analytical model of the convergenceconfinement type is proposed that accounts for the delayed action of bolts due to ground decompression prior to bolt installation. This factor leads to nonsimultaneous yielding, and more generally, a different stress history for each constituent, requiring special treatments in the incremental elastoplasticity calculations. Nonetheless, the resulting model remains sufficiently simple, and an analytical solution is still accessible. Charts are provided to allow for parametric studies and quick preliminary designs. Comparisons with 3D numerical calculations show that the model gives precise results if the correct convergence at the moment of bolt installation is used as an "external" input parameter, validating the homogenization approach. An approximate methodology based on previous works is proposed to determine this parameter to render the proposed model "self-sufficient." Its predictions are again compared to 3D numerical computations, and the results are found to be sufficiently accurate for practical applications.Key words: reinforcement, anisotropy, analytical, lining, yield, elastoplasticity.
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G., Radha Athipathi, Arunkumar C., and Umamaheswari N. "Investigations on prying forces in flexible connections of steel beams." International Journal of Structural Integrity 10, no. 3 (June 10, 2019): 415–24. http://dx.doi.org/10.1108/ijsi-01-2019-0003.
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Purpose The use of flexible connections throughout the steel structures provides a high level of stiffness compared to that of fully welded connections. Flexible connections allow for rotation to an extent, which make them perform better during earthquake than welded connections. In hanger connections, the applied load produces tension in the bolts and bolts are designed for tensile forces. When the deformation of the flange plate is equal to that of the bolts, a plastic hinge is formed in the flange plate at the weld line and the bolts are pulled to failure. If the attached plate is allowed to deform, additional tensile forces called prying forces are developed in the bolts. The paper aims to discuss these issues. Design/methodology/approach This paper includes the results of investigation on prying force in T-stub connection fabricated with normal grade bolts and high strength friction grip (HSFG) bolts. Finite element analysis has been carried out by creating models and analyzing the effect of external tensile force and bolt force. For different grades of bolt (4.6, 8.8, 10.9, 12.9), the prying force is calculated. Findings It is found that prying force is increasing with the change in grade of bolt used from normal to HSFG. The results obtained from analysis using IS 800:2007 codal provision are also included. It is observed that HSFG bolts do not allow for any slip between the elements connected and hence rigidity is increased. Originality/value The prying force mainly depends on geometrical parameter of the connection. In this research work, the variation of prying force was studied based on the variation in dimensions of T-stub angle section and bolt grade (4.6, 8.8, 10.9, 12.9). The method of obtaining prying force from bolt load and applied load is a unique approach. The results of FE analysis is validated with the analytical calculation as per IS 800:2007 code provisions, which shows the originality of the research.
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Hockey, B., F. Lam, and H. GL Prion. "Truss plate reinforced bolted connections in parallel strand lumber." Canadian Journal of Civil Engineering 27, no. 6 (December 1, 2000): 1150–61. http://dx.doi.org/10.1139/l00-040.
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This paper summarizes the results of an investigation into the behaviour of truss plate reinforced single and multiple bolted connections in parallel strand lumber (PSL) under static tension loading. Sixty single-bolt connections were tested with bolt and PSL size combinations of 12.7 mm bolts in 38×140 mm specimens, 15.9 mm bolts in 89×140 mm specimens, and 22.2 mm bolts in 133×191 mm specimens. Another sixty multiple-bolt specimens were tested, using the above-mentioned PSL size and bolt combinations. The multiple-bolt connections consisted of two rows of five bolts in the 38×140 mm and 89×140 mm specimens and two rows of two bolts in the 133×191 mm specimens. Each connection was configured according to the Canadian Standard for Engineering Design in Wood (CAN/CSA 086.1-94) in terms of bolt spacing, edge distances, and end distances. All reinforced single-bolt connections had average ultimate strength increases, compared to unreinforced connections, of 3% for the 133×191 mm, 12% for the 89×140 mm, and 37% for the 38×140 mm specimens. Reinforcement had little effect on the strength of multiple-bolt connections in both the 38×140 mm specimens and the 89×140 mm specimens. The reinforced four-bolt connections in the 133×191 mm specimens had a 7% increase in average ultimate strength. Reinforcement significantly improved the ductility in all the connections tested. Key words: timber connections, parallel strand lumber, multiple bolts, reinforcement, truss plates, ductility, composite wood products, testing, experimental, composite structural lumber.
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Mínguez, José María, and Jeffrey Vogwell. "Theoretical Analysis of Preloaded Bolted Joints Subjected to Cyclic Loading." International Journal of Mechanical Engineering Education 33, no. 4 (October 2005): 349–57. http://dx.doi.org/10.7227/ijmee.33.4.5.
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In this paper the performance of preloaded bolted joints is analysed. The prior torque tightening creates compression in the clamped members and tension in the bolt. So, when an external tensile load is applied to the joint a large amount of it is taken up by the members, thereby relaxing their compression, at the expense of only a slight increase in bolt tension. In this way preloading the joint has the effect of changing the bolt fatigue regime from a low mean load with high alternating load to a high mean load with a low alternating load. This is beneficial for its fatigue life.
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Kim, Noh Yu, and Sang Soon Lee. "Elastic Property Measurement of High-Tension Bolt Based on Mode Converted Ultrasound." Key Engineering Materials 326-328 (December 2006): 709–12. http://dx.doi.org/10.4028/www.scientific.net/kem.326-328.709.
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Elastic properties of high tension bolt are evaluated non-destructively by measuring acoustic longitudinal and shear wave velocities using mode-converted ultrasound. Mode-converted longitudinal and shear waves along bolt are captured to calculate acoustic wave velocities and determine elastic constants such as Young’s modulus and Bulk modulus based on acoustoelasticity. Ray analysis to select a specific mode conversion from longitudinal mode to shear mode is carried out and discussed with experimental results. From experiment results of maximum 5% of measurement error, it is shown that the proposed mode-converted ultrasonic technique is very effective and sensitive enough to characterize mechanical modulus of high-tension bolts quantitatively.
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Jia, Hou Sheng, Xi Dong Zhao, Ming Jiang Yu, and Xiao Long Yang. "Research to the Tension Monitoring Instrument of Bolt and Cable in Multi-Point." Advanced Materials Research 868 (December 2013): 255–60. http://dx.doi.org/10.4028/www.scientific.net/amr.868.255.
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Since safety of roadway and steady of rock depend on bolt and cable supporting quality [~[, it is important to evaluate timely bolt and cable supporting quality that monitors tension state of bolt and cable. With separated type design, the monitoring instrument, which is to monitor tension of multiple survey point and separation type Bolt and Cable, is made up of tension of bolt and cable sensor and secondary measuring instrument. This paper focuses on the composition and the basic principle of the tension of bolt and cable sensor structure, the composition of secondary measuring instrument structure and functional partition of the chips and circuit theory of the monitoring instrument. This paper introduces the concrete implementation way and the conditions of usage of the monitoring instrument and introduces the monitor in the application of the auxiliary slot of 22301 working face of Shen Dong coal group Shi Ge Tai ore.
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Chapman, Ian, John Newnham, and Paul Wallace. "The Tightening of Bolts to Yield and Their Performance Under Load." Journal of Vibration and Acoustics 108, no. 2 (April 1, 1986): 213–21. http://dx.doi.org/10.1115/1.3269326.
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The mechanism of tightening bolted joints and the stress distribution in the bolt are analyzed. Measurements were made of static and dynamic strength of joints. It is shown that all bolts behave elastically when external loads are applied to the joint even when the fastener was tightened to its torque-tension yield point. It is shown that joints generally fail when the external loads are sufficient to overcome the bolt preload. Fatigue reesults show that joint fatigue strength increases with preload, and that high fatigue bolts gave an improvement over standard fasteners at all preloads.
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Guzas, Emily, Kevin Behan, and John Davis. "3D Finite Element Modeling of Single Bolt Connections under Static and Dynamic Tension Loading." Shock and Vibration 2015 (2015): 1–12. http://dx.doi.org/10.1155/2015/205018.
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The Naval Undersea Warfare Center has funded research to examine a range of finite element approaches used for modeling bolted connections subjected to various loading conditions. Research focused on developing finite element bolt representations that were accurate and computationally efficient. A variety of finite element modeling approaches, from detailed models to simplified ones, were used to represent the behavior of single solid bolts under static and dynamic tension loading. Test cases utilized models of bolted connection test arrangements (static tension and dynamic tension) developed for previous research and validated against test data for hollow bore bolts (Behan et al., 2013). Simulation results for solid bolts are validated against experimental data from physical testing of bolts in these load configurations.
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Adams, RD, T. Brearley, E. Nehammer, E. Rouse, and D. Vaughan. "Frictional damping in hollow beam structures joined by bolts, rivets, and adhesive." Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 235, no. 6 (May 12, 2021): 1477–87. http://dx.doi.org/10.1177/1464420721994305.
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The objective of this work was to investigate how different joining techniques affect the level of damping in structures. Beams were constructed from four different joining techniques, bolting, riveting, adhesive bonding, and brazing by joining two lengths of steel each with a ‘U’-shaped cross-section. They were joined such that the edges of the ‘U’ overlapped to form a tube. The damping of each beam was determined by flexural vibration. The bolted beam had a series of bolts along its length. The effect of removing bolts was investigated. It was found that removing bolts increased damping. When bolts were removed successively from holes at the end of the beam, the damping increased more than when bolts were removed from holes in the middle of the beam. A further objective of this project was to investigate the effect of introducing penetrant between two surfaces. WD-40 was introduced between the contacting surfaces for the beams joined by mechanical fastening. The penetrant had the effect of increasing damping. This may be because the penetrant has the effect of increasing the relative displacement between the two beams, leading to greater energy dissipation. Introducing penetrant also changed the order of which beam had the greatest damping, with the bolted beam now having greater damping than the riveted beam. The effect of increasing bolt tension on the bolted beam was also investigated. When the beams were dry, increasing bolt tension reduced the damping, but when penetrant was introduced increasing the bolt tension increased the damping. A comparison between the damping properties from different joining techniques was made. The conclusions could be applied in industry by engineers constructing beams of a similar fashion.
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Korzeniowski, Waldemar, Krzysztof Skrzypkowski, and Łukasz Herezy. "Laboratory Method for Evaluating the Characteristics of Expansion Rock Bolts Subjected to Axial Tension / Laboratoryjna Metoda Badania Charakterystyk Kotew Rozprężnych Poddanych Rozciąganiu Osiowemu." Archives of Mining Sciences 60, no. 1 (March 1, 2015): 209–24. http://dx.doi.org/10.1515/amsc-2015-0014.
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Abstract Rock bolts have long been used in Poland, above all in the ore mining. Worldwide experience (Australia, Chile, Canada, South Africa, Sweden, and USA) provides evidence of rock bolt supports being used for loads under both static and dynamic conditions. There are new construction designs dedicated to the more extreme operating conditions, particularly in mining but also in tunneling. Appreciating the role and significance of the rock bolt support and its use in Polish conditions amounting to millions of units per year, this article describes a new laboratory test facility which enables rock bolt testing under static load conditions. Measuring equipment used as well as the possibilities of the test facility were characterized. Tests were conducted on expansion rock bolt supports installed inside a block simulating rock mass with compression strength of 80 MPa, which was loaded statically as determined by taking account of the load in order to maintain the desired axial tension, which was statically burdened in accordance with determined program load taking into consideration the maintenance of set axial tension strength at specified time intervals until capacity was exceeded. As an experiment the stress-strain characteristics of the rock bolt support were removed showing detailed dependence between its geometrical parameters as well as actual rock bolt deformation and its percentage share in total displacement and deformation resulting from the deformation of the bolt support elements (washer, thread). Two characteristic exchange parts with varying intensity of deformation /displacement per unit were highlighted with an increase in axial force static rock bolt supports installed in the rock mass.
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Hassan, Md Kamrul, Bulbul Ahmed, Anmol Ram, and Swapan Saha. "Behaviour and Design of Bolt-Coupler Connections under Compression in Prefabricated CFST Columns." Sustainability 14, no. 19 (September 26, 2022): 12166. http://dx.doi.org/10.3390/su141912166.
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The paper presents the investigated results of bolt-coupler connections under compression experimentally. Bolt-coupler connections have been developed recently for prefabricated column-to-column (PCC) connections to simplify the construction process of prefabricated concrete-filled steel tubular (CFST) columns and to transfer the upper column load to the bottom column through bolt-coupler connections. However, the behaviour of bolt-coupler connections under compression has not been investigated in the past although there are some experimental and numerical studies conducted on bolt-coupler connections under tension. To address these research gaps, the behaviour of bolt-coupler connections under compression has been investigated. The main parameters considered in this study are bolt diameters (M16, M20, M24), bolt grades (8.8, 10.9 grade), gap inside the coupler between two bolts of bolt-coupler connection (0, 10, 20 mm), and coupler grade (5.6, 8.8 grade). It is observed that the ultimate capacity of bolt-coupler connections is reduced significantly with an increase in the bolt gap inside the coupler of the bolt-coupler connection. Based on the test data, a design equation is developed to determine the design capacity of bolt-coupler connections under compression, which will be very useful in designing the PCC connections of sustainable prefabricated CFST columns.
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CHOI, JAE-HYOUK, and KENICHI OHI. "PSEUDO-DYNAMIC RESPONSE TESTS ON SELF-RETURNING JOINT MECHANISM USING Ni-Ti-Co ALLOY." International Journal of Modern Physics B 20, no. 25n27 (October 30, 2006): 4439–44. http://dx.doi.org/10.1142/s0217979206041483.
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This paper deals with a beam-to-column connection using mechanical fasteners made of shape memory alloy, abbreviated as 'SMA bolt' hereafter. A flush-type endplate connection at beam-ends is arranged by use of SMA bolts, and the connection works as a super-elastic joint mechanism. This paper describes sub-structure pseudo-dynamic response tests on a super-elastic frame system with fictitious tension-bar diagonal braces. For the comparison, a similar structural system bolted by ordinary mild-steel bolts is also tested pseudo-dynamically. It was observed that the SMA bolt system returned to its original position, while the ordinary bolt system showed some permanent set after earthquakes. Additionally, response analysis based on a nonlinear-elastic model and a slip model is performed and compared with the test results.
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Korzeniowski, Waldemar, Krzysztof Skrzypkowski, and Krzysztof Zagórski. "Reinforcement of Underground Excavation with Expansion Shell Rock Bolt Equipped with Deformable Component." Studia Geotechnica et Mechanica 39, no. 1 (March 28, 2017): 39–52. http://dx.doi.org/10.1515/sgem-2017-0004.
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AbstractThe basic type of rock mass reinforcement method for both preparatory and operational workings in underground metal ore mines, both in Poland and in different countries across the world, is the expansion shell or adhesive-bonded rock bolt. The article discusses results of static loading test of the expansion shell rock bolts equipped with originally developed deformable component. This component consists of two profiled rock bolt washers, two disk springs, and three guide bars. The disk spring and disk washer material differs in stiffness. The construction materials ensure that at first the springs under loading are partially compressed, and then the rock bolt washer is plastically deformed. The rock bolts tested were installed in blocks simulating a rock mass with rock compressive strength of 80 MPa. The rock bolt was loaded statically until its ultimate loading capacity was exceeded. The study presents the results obtained under laboratory conditions in the test rig allowing testing of the rock bolts at their natural size, as used in underground metal ore mines. The stress-strain/displacement characteristics of the expansion shell rock bolt with the deformable component were determined experimentally. The relationships between the geometric parameters and specific strains or displacements of the bolt rod were described, and the percentage contribution of those values in total displacements, resulting from the deformation of rock bolt support components (washer, thread) and the expansion shell head displacements, were estimated. The stiffness of the yielded and stiff bolts was empirically determined, including stiffness parameters of every individual part (deformable component, steel rod). There were two phases of displacement observed during the static tension of the rock bolt which differed in their intensity.
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NISHIWAKI, Takeo, Mitsutoshi KURODA, and Nobutoshi MASUDA. "Bolt length and hole alignment in long-bolt tension-type connections." Doboku Gakkai Ronbunshu, no. 437 (1991): 115–23. http://dx.doi.org/10.2208/jscej.1991.437_115.
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Kawohl, Anne, and Jörg Lange. "Experimental study of post-fire performance of high-strength bolts under combined tension and shear." Journal of Structural Fire Engineering 7, no. 1 (March 14, 2016): 58–68. http://dx.doi.org/10.1108/jsfe-03-2016-005.
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Purpose This study aims to verify whether the reduction factors for the post-fire performance of Grade 10.9 bolts stated in an earlier study at the TU Darmstadt are also valid for shear and combined tension and shear. Design/methodology/approach Tests on Grade 10.9 bolt sets under combined tension and shear were carried out. The tested bolts were heated and cooled without being stressed by an additional mechanical load before being tested. Findings The test results show that the reduction factors can also be adopted for bolts under combined tension and shear, but the tension-shear-ratio has an influence on the load bearing capacity. Originality/value The post-fire performance of high-strength bolts is of special interest when a building structure is evaluated after an event of fire. In contrast to conventional structural steel, high-strength bolts do not recover their original strength and material properties.
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Lowe, S. A. "Tightening a Tension-Control Bolt without a Tension-Control Gun." Practice Periodical on Structural Design and Construction 24, no. 4 (November 2019): 06019003. http://dx.doi.org/10.1061/(asce)sc.1943-5576.0000455.
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Kim, Dong Hak, Ki Seong Seo, and Ju Cahn Lee. "The Effect of a Free Drop Impact on the Bolted Joint of the Radioactive Transport Package." Key Engineering Materials 345-346 (August 2007): 1421–24. http://dx.doi.org/10.4028/www.scientific.net/kem.345-346.1421.
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In this study the effect of a free drop impact on the bolted joint of the transport package of radioactive material was studied under various directions. A drop test of a type A or a type IP transport package of radioactive material should be conducted under normal transport conditions. After a drop test the radioactive content of the transport package should not be loss or dispersal. A bolt tension during a drop impact under various directions was measured using a force sensor. And the torque to loosen a bolt was measured after the tests. A bolt tension measured by the tests was compared with the result of a finite element analysis. The effect of the drop direction was examined. The vertical drop directions shows larger bolt tension than horizontal drop. For the torque to loosen a bolt, a horizontal drop condition shows larger value than a vertical drop direction.
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Feng, Yan Ting, Hao Ke, Xue Xia Xu, Xiao Hao Dai, Hui Fan, Xiao Guang Niu, and Hai Jun Ma. "Research on Characteristics of Joint Point of Power Transmission Tower." Applied Mechanics and Materials 457-458 (October 2013): 624–28. http://dx.doi.org/10.4028/www.scientific.net/amm.457-458.624.
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Based on tension tests for tower bolt, it was found that the pretension increased with the extension of torque retention time, and manifested characteristics of decreasing at early stage then increasing at later stage during the tension process, that provided guidance for bolt fastening.
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Yang, Xu, Honggang Lei, and Y. Frank Chen. "Constant amplitude fatigue test research on M20 high-strength bolts in grid structure with bolt–sphere joints." Advances in Structural Engineering 20, no. 10 (December 26, 2016): 1466–75. http://dx.doi.org/10.1177/1369433216682506.
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The grid structure with bolt–sphere joints is one type of large-span spatial structures. Due to small induced force, light weight, large stiffness, and good seismic performance, such structural system has been widely adopted in industrial plants with suspending cranes. The damage of the grid structure with bolt–sphere joints tends to occur at high-strength bolt joints, with fatigue fracture as the primary failure mode. The alternating and reciprocating action of the suspending crane will cause fatigue problems to the structural components of the grid structure, including rod, cone, sealing plate, bolted sphere, and high-strength bolt. The threads in high-strength bolt result in a significant stress concentration leading to bolt fatigue which is the key issue of fatigue failure. In this study, systematic constant amplitude fatigue tests were conducted for 18 M20 high-strength bolt made of 40Cr material using the developed efficient and smooth loading equipment combined with the Amsler fatigue testing machine, in which the tension condition of the high-strength bolt in the grid structure was simulated, simulation of high-strength bolt in tension works of grid structure. In addition, the signal-to-noise curve and the calculation method of constant amplitude fatigue for the high-strength bolt are proposed in grid structure with bolt–sphere joints.
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Bull, Lucy, Eric J. Palmiere, Richard P. Thackray, Ian W. Burgess, and Buick Davison. "Tensile Behaviour of Galvanised Grade 8.8 Bolt Assemblies in Fire." Journal of Structural Fire Engineering 6, no. 3 (June 17, 2015): 197–212. http://dx.doi.org/10.1260/2040-2317.6.3.197.
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In structural fire engineering, the importance of bolt assemblies is often overlooked. Connection design uses the temperature-dependent bolt strength-reduction factors prescribed in Eurocode 3, despite the existence of two distinct failure modes under tension; necking of the bolt shank, and thread-stripping. While literature exists to predict failure modes at ambient temperature, there is no method for failure mode prediction for elevated temperatures where ductility is critical to avoid collapse. Galvanised M20 structural bolt assemblies and bolt material from a single batch have been tested under tension at a range of temperatures and strain-rates typical of those experienced in fire. Turned-down bolt test data produced stress-strain curves characteristic of different microstructures at ambient temperature, despite a tempered-martensitic microstructure being specified in the standards. The failure modes of bolt assemblies were found to be dependent on the as-received microstructure at ambient temperature. At elevated temperatures, however, only thread-stripping was observed.
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Kim, Sang-Hwan, Ki-Il Song, and Jae-Hyun Park. "Experimental evaluation of the active tension bolt." Geomechanics and Engineering 11, no. 2 (August 25, 2016): 177–95. http://dx.doi.org/10.12989/gae.2016.11.2.177.
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Mikhailovsky, Leonid, D. J. Laurie Kennedy, and Raymond W. S. Lee. "Flexural behaviour of bolted joints of corrugated steel plates." Canadian Journal of Civil Engineering 19, no. 5 (October 1, 1992): 896–905. http://dx.doi.org/10.1139/l92-101.
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Even though the design of corrugated steel plate culverts is based on compression ring theory, soil-steel structure interaction will likely lead to the development of bending moments in the steel plates. Successful application of these structures requires that these moments be accommodated without distress, while the plate carries axial thrust. This requires ductile flexural behaviour.The results of 13 flexural tests, with two-point loading, on lap joints of 3, 5, and 7 mm thick corrugated steel plates, as well as one test on plain 5 mm thick corrugated steel plate, are reported. Bolt configurations consisting of 2, 3, and 4 bolts per complete corrugation were tested to investigate the postulate that lap joints subject to bending moments can be made in a correct or incorrect manner. Correct lap joints are those that do have a bolt near the edge of the lap on the tension side where prying tends to occur, that is, where the gap between the lapped plates tends to open up when the joint is subject to moment. Incorrect laps do have a bolt at this location. Laps with 2 bolts are either correct for both positive and negative bending moments or incorrect for both. Statistically, laps with 3 bolts will be incorrect 75% of the time and laps with 4 bolts all the time.The tests confirm the postulate and show that, in the incorrect laps, tearing of the corrugated plates, starting at the edges of the bolt holes in the critical location where there is prying, occurs shortly after the maximum moment is reached. The tearing leads to a reduction in the moment resistance and reduced ductility even though the maximum moment for incorrect laps may be comparable to that for correct laps. Correct laps exhibit tremendous ductility, achieving joint rotations of 0.4 radians or more. Laps with 4 bolts per corrugation are weaker flexurally than laps with 2 bolts per corrugation because the critical net area on the tension side is less. Shaped washers placed under the bolt heads at the critical location do not improve the behaviour. Inadequate torquing in the bolts leads to increased flexibility, and reduced strength of the lap joints and increased opening of the gap between the plates. Key words: bolted, corrugated, culvert, ductility, flexure, joints, lap, moment resistance, plate, steel, tearing.
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Xue, Bing, Yong Chen, Cong Chen, and Ji Yang Wang. "Experimental Study of Inner-and-Outer Steel Flanges Subjected to Tension and Bending Loads." Key Engineering Materials 737 (June 2017): 459–64. http://dx.doi.org/10.4028/www.scientific.net/kem.737.459.
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Inner-and-outer steel flange has gained many attentions in China. This type flange has both inner and outer rings, as well as bolts. To gain insight into the intrinsic characteristics of the flange, an experimental study is conducted, taking into account that the tension and bending loads are imposed simultaneously. The varying of relative displacement between two adjacent flange planes with external loading is surveyed. It is indicated that the deformation is almost linearly increased with the external loads, if there is no yielded bolt. Strain gauges are employed to capture the strain distribution in the ribs as well as the tube. The internal tension force of bolt is also measured in the test. It is revealed that the failure mode of the flange is the breaking of the outer bolts. Moreover, the existence of the tension load would reduce the bending bearing capacity of the flange, and prying force could be ignored. It is concluded that the plane-section assumption holds approximately. Accordingly, formulas are given to compute the bearing capacity of the flange. It is found that the computing method is quite conservative if the position of rotation axis takes a value of 0.8 times of the diameter of the steel tube.
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Nassar, Sayed A., and Basil A. Housari. "Effect of Thread Pitch and Initial Tension on the Self-Loosening of Threaded Fasteners." Journal of Pressure Vessel Technology 128, no. 4 (July 30, 2005): 590–98. http://dx.doi.org/10.1115/1.2349572.
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A mathematical model and an experimental procedure are presented to study the self-loosening phenomenon of threaded fasteners that are subjected to cyclic transverse loads. The study investigates the effect of thread pitch, initial bolt tension, and the amplitude of the external excitation on the loosening of a single-bolt joint. The rate of drop in the joint clamp load (fastener tension) per cycle, as well as the total number of cycles that would cause the complete loss of clamp load, are monitored. In the mathematical model, the differential equations of linear and angular motion of the bolt are formulated in terms of the system properties and the external cyclic transverse excitation. Numerical integration of the equation of angular motion provides the bolt rotation in the loosening direction, which causes the partial or full loss of the clamp load. An iterative MATLAB code is developed and used for the calculation of tension loss in the fastener tension due to the self-loosening. Analytical and experimental results are discussed.
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Jasztal, Michał, and Mariusz Ręgowski. "Fatigue life analysis of bolt joints with use of ANSYS software." Mechanik 91, no. 7 (July 9, 2018): 600–602. http://dx.doi.org/10.17814/mechanik.2018.7.96.
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The paper presents selected problems of fatigue life of bolt joints. An analysis of factors influencing fatigue life of bolt joints was performed and selected methods of improving life were described. Authors presents examples of numerical calculations with use of ANSYS software which depict influence of pre-tension in the bolt on fatigue life of the joint. Presented results of life calculation were carried out for bolt joint loaded along bolt axis and for bolt lap joint loaded perpendicular to bolt axis.
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Ruan, Yangjie, Bin Luo, Mingmin Ding, Lifan Huang, and Zhengxing Guo. "Theoretical and Experimental Study on the Antisliding Performance of Casting Steel Cable Clamps." Advances in Civil Engineering 2019 (May 2, 2019): 1–18. http://dx.doi.org/10.1155/2019/1438754.
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For large-span cable structures, a cable clamp is a key joint that connects adjacent structural components. In general, the antisliding performance of cable clamps determines their resistance capacity, and the antisliding force is generated by the clamping force induced by the high-strength bolts and the contact surfaces between the cable and the clamp. Since the existing methods are not sufficiently comprehensive for use to predict the precise bolt preload, a theoretical model developed by considering transversely isotropic material and the generalized Hook’s law is presented to predict the attenuation values of the bolt clamping force and the corresponding parameters. Then, to meet the requirements of Eurocode 3, a new laboratory test is performed to reveal the antisliding mechanism of cable clamps, considering the effects of long-term creep and cable tension. According to the results of the data collected by real-time monitoring, the actual ultimate antisliding force of the clamp and the comprehensive friction coefficient are determined. Finally, a comparative study between the theoretical results and the experimental results is conducted. The proposed theoretical model can predict the actual attenuation of the bolt clamping force after cable tension. The results show that the stiffness of the clamp plate should be minimized when designing the clamp to reduce the loss of the bolt preload.
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Shrih, Ali, Adeeb Rahman, and Mustafa Mahamid. "Finite element analysis of tension-loaded ASTM A325 bolts under simulated fire loading." Journal of Structural Fire Engineering 9, no. 1 (March 12, 2018): 2–18. http://dx.doi.org/10.1108/jsfe-06-2016-0006.
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Purpose Nuts and bolts have been used as fasteners of steel structures for many years. However, these structures remain susceptible to fire damage. While conducting fire experiments on steel structures is sometimes necessary, to better understand their behavior, such experiments remain costly and require specialized equipment and testing facilities. This paper aims to present a highly accurate three-dimensional (3D) finite element (FE) model of ASTM A325 bolt subjected to tension loading under simulated fire conditions. The FE model is compared to the results of experimental testing for verification purposes and is proven to predict the response of similar bolts up to certain temperatures without the need for repeated testing. Design/methodology/approach A parametric 3D FE model simulating tested specimens was constructed in the ANSYS Workbench environment. The model included the intricate details of the bolt and nut threads, as well as all the other components of the specimens. A pretension load, a tension force and a heat profile were applied to the model, and a nonlinear analysis was performed to simulate the experiments. Findings The results of the FE model were in good agreement with the experimental results, deviations of results between experimental and FE results were within acceptable range. This should allow studying the behavior of structural bolts without the need for expensive testing. Originality/value Detailed 3D FE models have been created by the authors have been created to study the behavior of structural bolts and compared with experiments conducted by the authors.
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Xie, Zhengzheng, Nong Zhang, Qun Wei, Jin Wang, and Mostafa Sharifzadeh. "Study on Mechanical Properties and Application of a New Flexible Bolt." Applied Sciences 11, no. 3 (January 20, 2021): 924. http://dx.doi.org/10.3390/app11030924.
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As mining depth extends continuously, complex geological environment and strong mining stress pose serious challenges against excavation safety and higher demand for bolt support. To meet the challenges, a new type of flexible bolt is developed that is free from the limitation of excavation height and can be installed quickly. The flexible bolts have a tail structure which is squeezed together by the locking casing and the steel-strand rod. The tail structure forms the thread through the rolling process, and then can be quickly installed by the nut rotation type, which avoids the disadvantages of the cable tension installation. Through the flexible long bolts, the thick anchoring layer of the roof can be constructed, and the safety control of the roadway is realized. To obtain the optimal specifications, locking casings of three diameters and lengths were used to prepare bolt samples for static tensile test. Test results show that when the diameter of locking casing is fixed, the peak resistance increases as the length of locking casing increases, but the increased amplitude tends to reduce gradually. When the length of locking casing is fixed, too large a diameter makes the mechanical property unstable. Finally, the optimal length and diameter of locking casing are set at 120 and 30 mm, respectively. In addition, cyclic loading tests were conducted, the results of which indicate that cyclic loading does not change the stress state within the bolts and that flexible bolts display a stable mechanical property. Field results indicate that flexible bolts achieve low damage of the surrounding rock and control the maximum roof fracture depth within 2.1 m, thus guaranteeing the roadway safety.