Academic literature on the topic 'Bolt tension'
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Journal articles on the topic "Bolt tension"
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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.
Dissertations / Theses on the topic "Bolt tension"
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Martinez, Garcia Jairo Andres. "A Novel Ultrasonic Method to Quantify Bolt Tension." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4145.
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The threaded fasteners are one of the most versatile methods for assembly of structural components. For example, in bridges large bolts are used to fix base columns and small bolts are used to support access ladders. Naturally not all bolts are critical for the operation of the structure. Fasteners loaded with small forces and present in large quantities do not receive the same treatment as the critical bolts. Typical maintenance operations such tension measurements, internal stress checking or monitoring of crack development are not practical due to cost and time constrains. Although failure of a single non-critical fastener is not a significant threat to the structure's stability, massive malfunction may cause structural problem such as insufficient stiffness or excessive vibrations.
The health of bolted joints is defined by a single parameter: the clamping force (CF). The CF is the force that holds the elements of the joint together. If the CF is too low, separation and bolt fatigue may occur. On the other hand, excessive CF may produce damages in the structural members such as excessive distortion or breakage. The CF is generated by the superposition of the individual tension of the bolts. The bolt tension, also referred as bolt preload, is the actual force that is stretching the bolt body. Maintaining the appropriate tension in bolts ensures a proper CF and hence a good health of the joint.
In this thesis, a novel methodology for estimating the tension in bolts using surface acoustic waves (SAWs) is investigated. The tension is estimated by using the reflection of SAWs created by the bolt head interference. Increments in the bolt tension raise the points of interaction between the waves and the bolt head (real area of contact), and hence the position of the reflective boundaries. The variations are estimated using the "conventional linear synthetic array" imaging technique. A singular transducer is actuated from predefined positions to produce an array of signals that are subsequently arranged and added to construct an acoustic image.
Three sets of experiment are presented in this research for validating the proposed concept: tension estimation of a ¼ inch stainless steel bolt, a ½ inch stainless steel bolt and ¼ inch grade 8 bolt. Acoustic images of the surface of the clamped plate illustrate a clear trend in the position of the reflective boundary when torque is changed. In all cases, the torque increments increase the real area of contact and therefore the position of the reflective boundary. As expected, the real area of contact grew from the bolt head center to the perimeter, which causes an effect of apparent movement of the boundary. This research proves the potential of the ultrasonic imaging methodology to measure applied tension. The result showed that the system can be used to successfully inspect tension in bolts of ½ and ¼ inches. The methodology investigated in this thesis is the first steps towards the development of bolt tension sensor based on surface acoustic waves.
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Kara, Emre. "A Numerical Study On Block Shear Failure Of Steel Tension Members." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606359/index.pdf.
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Block shear is a limit state that should be accounted for during the design of the steel tension members. This failure mechanism combines a tension failure on one plane and a shear plane on a perpendicular plane. Although current design specifications present equations to predict block shear load capacities of the connections, they fail in predicting the failure modes. Block shear failure of a structural connection along a staggered path may be the governing failure mode. Code treatments for stagger in a block shear path are not exactly defined. A parametric study has been conducted and over a thousand finite element analyses were performed to identify the parameters affecting the block shear failure in connections with multiple bolt lines and staggered holes. The quality of the specification equations were assessed by comparing the code predictions with finite element results. In addition, based on the analytical findings new equations were developed and are presented herein.
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Pascual, Pastor Ana María. "Fire behaviour of blind-bolted connections to concrete filled tubular columns under tension." Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/53240.
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[EN] Concrete filled steel tubular columns have many advantages in terms of bearing capacity, aesthetics, execution and fire resistance, thanks to the collaborative work of both materials steel and concrete. The effort made in the last decades to rise a high understanding of their behaviour subjected to different loads and assuming multiple variations has resulted in the wide spread of its use between the designers. Nonetheless, how to solve the connection with I-beams is still a handicap and requires a specific study.
One of the most common and popular solution to connect open section steel beams (I-beams) to open section steel columns are endplate connections. In the cases of columns with hollow section, special fastenings are needed, which are able to be tightened from one external side and are denominated blind-bolts. Nowadays, there are several fastener systems that allow these types of connections. The characterization of their response and their capacity to support different loads is the objective of several investigations, where the geometrical definition and the material properties are crucial parameters.
Despite the promising results of these connections at room temperature regarding their capability to resist bending moments, their performance is un-known at high temperatures. Therefore, the aim of this thesis is the study of the tensile behaviour of blind-bolts in endplate connections to concrete filled tubular columns at elevated temperatures and subjected to bending moment.
Primarily, the research comprises the understanding of the pure thermal transfer problem. The temperature distribution through the connection section is obtained experimental and numerically. The thermal parameters that characterize the connections response are determined through the calibration of the numerical models with the experiments. Secondly, the blind-bolt capacity under pull out and at high temperatures is under analysis. During the fire the temperature increases while connection transmits loads from the beam to the column, the objective of this dissertation is to know how the mechanical response of the pulled blind-bolts changes under these conditions. Thus, the study of the material properties dependent on the temperature and their effect on the connection response is covered by the investigation. Furthermore, the influence of the concrete and the type of fastener is a highlighted aspect through the thermal and the fire analysis.
Finally, the reliability of these connections to comply with requirements of 30 minutes fire exposure before the collapse is evaluated.
As a result, valuable Finite Element models able to simulate the thermal and thermo-mechanical behaviour of the connection are developed, providing useful behavioural patterns of the blind-bolts. Among the main conclusions, it is noted the temperature reduction due to concrete core in concrete filled columns compared to hollow sections, in the exposed bolt surface means 100ºC less. Conversely, a longer bolt shank of the fastener system embedded in concrete has a negligible effect on the temperature of the resistant part of the bolt. Regarding the fire capacity, the concrete core in the steel tube columns presents significant benefits in terms of fire resistance time and connection stiffness. Besides, the bolt anchorage enhances the stiffness at elevated temperatures, however, the failure of the shank next to the bolt head causes that the anchorage does not mean an improvement on the fire time resistance.[ES] Las columnas tubulares de acero rellenas de hormigón presentan múltiples ventajas en términos de capacidad de carga, estética, ejecución y resistencia al fuego, gracias a la acción combinada de acero y hormigón. El esfuerzo realizado en las últimas décadas por conocer su comportamiento frente a diferentes cargas y bajo distintos parámetros ha dado lugar a una amplia difusión de su uso entre los diseñadores. No obstante, la forma de resolver la conexión con vigas de sección en I sigue siendo un hándicap y requiere un estudio específico. Una de las soluciones más comunes y populares para conectar las vigas de acero de sección abierta (vigas I) a columnas de acero de sección abierta es la conexión con chapa de testa, que en el caso de sección hueca requiere de tornillos especiales denominados tornillos ciegos, puesto que reciben el par de apriete desde una cara de la sección. En la actualidad existen diversos sistemas de fijación que permiten este tipo de conexiones y cuya respuesta y caracterización es objeto de numerosas investigaciones. En este sentido, la definición geométrica de la unión y las propiedades de los materiales son parámetros cruciales en el rendimiento de la conexión. La presente tesis analiza el comportamiento de los tornillos ciegos en el área traccionada de conexiones de placa de testa a columnas tubulares de acero rellenas de hormigón sometidas a momentos de flexión y a elevadas temperaturas. Las prestaciones de esta solución constructiva para la unión viga-columna tubular, junto con la ausencia de datos relacionados con su comportamiento en situación de incendio la convirtió en el objetivo del trabajo. En primer lugar, la investigación aborda el problema de transferencia de calor, analizando experimental y numéricamente la distribución de temperaturas en la sección de la conexión. En esta parte del estudio se obtienen los parámetros térmicos que caracterizan la respuesta térmica de la conexión a través de la calibración de los modelos numéricos con los datos experimentales. En segundo lugar, se realiza el estudio de la capacidad de los tornillos ciegos para soportar cargas de tracción en situación de incendio, es decir, se analiza cómo cambia el comportamiento de la conexión con sus características alteradas debido a las altas temperaturas. El estudio de las propiedades del material en función de la temperatura y su efecto sobre la respuesta de la conexión constituyen una parte importante de la investigación. Además, se evalúa la influencia del hormigón y el tipo de elemento de sujeción tanto en el comportamiento mecánico como termo-mecánico de la conexión. Por último, se estudia la capacidad de las uniones para cumplir con requerimientos de exposición al fuego de 30 minutos previamente al colapso. Como resultado de este trabajo se obtuvieron modelos de elementos finitos capaces de simular la conexión térmica y termo-mecánicamente, proporcionando patrones de comportamiento de gran utilidad en el diseño de las mismas. Entre las principales conclusiones, se observó la reducción de la temperatura en los tornillos gracias al núcleo de hormigón en columnas de hormigón lleno en comparación con secciones huecas, que ya en la superficie expuesta del tornillo se cuantificaba en 100ºC menos. Por el contrario, los elementos de fijación que presentaban mayor longitud de vástago de tornillo embebida en el hormigón, no generaban un efecto significativo sobre la temperatura de la parte resistente del perno. En cuanto a la capacidad resistente frente a fuego, el núcleo de hormigón supuso una mejora en términos de rigidez y de tiempo de resistencia al fuego. Sin embargo, el fallo de los pernos en una sección próxima a la superficie expuesta redujo el efecto esperado del anclaje del tornillo, que si bien implicaba una mayor rigidez de la conexión, no parecía mejorar el tiempo de resistencia a fuego. Finalmente se planteó la necesidad de
[CAT] Els pilars tubulars d'acer omplerts de formigó (CFT) presenten molts avantatges en termes de capacitat de carrega, estètica, execució i resistència al foc, gràcies a l'acció combinada de l'acer i el formigó. L'esforç realitzat en les darreres dècades per conèixer el seu comportament enfront a diferents càrregues i sota distints paràmetres ha donat lloc a una amplia difusió del seu ús entre el dissenyadors. No obstant això, la manera de resoldre la connexió amb bigues de secció en I, continua sent un handicap i requereix d'un estudi específic. Una de les solucions més comuns i populars per a connectar les bigues d'acer de secció oberta (bigues I) a columnes d'acer de secció oberta és la connexió amb 'chapa de testa', que en el cas de la secció buida requereix de perns especials denominats perns cecs perquè es rosquen des d'una cara de la secció. En l'actualitat existeixen diversos sistemes de fixació que permeten aquest tipus de connexions, la resposta i caracterització dels quals es l'objectiu de nombroses recerques. En aquest sentit, la definició geomètrica de la unió i les propietats dels materials son paràmetres crucials en el rendiment de la connexió. Aquesta tesi analitza el comportament dels perns cecs en l'àrea traccionada de connexions de 'chapa de testa', a pilars tubulars d'acer omplerts de formigó, sotmeses a moments de flexió i a elevades temperatures. Les prestacions d'aquesta solució constructiva per a la unió biga-pilar tubular junt amb l'absència de dades relacionades amb el comportament en situació d'incendi, la van convertir en l'objectiu d'aquest treball. En primer lloc, la recerca aborda el problema de transferència de calor, analitzant tant experimental com numèricament la distribució de temperatures en la secció de la connexió. En aquesta part de l'estudi, s'obtenen el paràmetres tèrmics que caracteritzen la resposta tèrmica de la connexió mitjançant el calibratge del models numèrics amb les dades experimentals. En segon lloc, es realitza l'estudi de la capacitat dels perns cecs per a suportar càrregues de tracció en situació d'incendi, es a dir, s'analitza com canvia el comportament de la connexió amb les seues característiques alterades degut a les altes temperatures. L'estudi de les propietats del material en funció de la temperatura i el seu efecte en la resposta de la connexió formen també part de la recerca. Un contingut important d'aquest treball consisteix en determinar l'influencia del formigó i el tipus d'element de fixació tant en el comportament mecànic com termo-mecànic de la connexió. Per últim, s'estudia la capacitat de les unions per a complir amb els requeriments d'exposició al foc de 30 minuts prèviament al col·lapse. Com a resultat d'aquest treball s'obtingueren models d'elements finits amb capacitat per a simular el comportament tèrmic i termo-mecànic de la connexió, proporcionant patrons de comportament de gran utilitat en el disseny. Entre les principals conclusions, es va observar la reducció de la temperatura en els perns gràcies al nucli de formigó en pilars omplerts de formigó en comparació amb el pilars buits, on ja en la superfície esposada del cargol es quantificava en 100 ºC menys. Pel contrari, els elements de fixació que presentaven major longitud de embeguda en el formigó, no generaven un efecte significatiu en la temperatura de la part resistent del pern. En quant a la capacitat resistent davant del foc, el nucli de formigó va suposar una millora en termes de rigidesa i de temps de resistència al foc. Tanmateix, la fallada dels perns en una secció pròxima a la superfície esposada va reduir l'efecte esperat de la fixació del pern, que si be implicava una major rigidesa de la connexió, no semblava millorar el temps de resistència al foc. Finalment, es va plantejar la necessitat de aprofundir en l'anàlisi incorporant un major rang de paràmetres.
Pascual Pastor, AM. (2015). Fire behaviour of blind-bolted connections to concrete filled tubular columns under tension [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/53240
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Barnett, Tobias C. "Assessment of clamping behaviour of a newly developed blind bolt, and an investigation into its performance in the tension region of moment resisting connections using open and hollow sections." Thesis, Nottingham Trent University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366362.
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Barke, Derek Woolrich 1975. "An in situ test for stress corrosion damage and tension in bolts." Monash University, Dept. of Mechanical Engineering, 2002. http://arrow.monash.edu.au/hdl/1959.1/7686.
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Schnupp, Keith Otto. "Effects of Head Size on the Performance of Twist-Off Bolts." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/43600.
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This study examines a specific application of button-head type twist-off bolts. Currently, the Research Council on Structural Connections Specification (2000) removes the requirement for ASTM F436 washers (ASTM 2000a) under the bolt head of twist-off bolts where the head diameter equals or exceeds that of an ASTM F436 washer when oversized and slotted holes are used. The need for washers is also removed for A490 strength bolts used on steels with specified yield strengths less than 40 ksi provided that the head diameter equals or exceeds an ASTM F436 washer.
The ASTM F1852 Specification (ASTM 2000b) allows for head diameter dimensions that are slightly smaller than an ASTM F436 washer. Following the RCSC Specification, manufacturers that produce bolts using the ASTM F1852 dimensions are required to use ASTM F436 washers under the bolt head. The discrepancies between the specifications lead to this study, which involved the testing of button-head type twist-off bolts with two different head diameters, both of which were smaller than an ASTM F436 washer.
Five bolt diameters between 5/8 in and 1-1/8 in. were tested in standard, oversized, and long-slotted holes. The performance of the twist-off bolts was determined by measuring and comparing the achieved relaxed pretension force in the bolt after tightening. It was found that twist-off bolts with head diameters less than an ASTM F436 washer had no trouble attaining their required minimum pretension force. Bolt head diameter and hole size were found to have no significant influence on the pretension force that was achieved for all bolts tested.Master of Science
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MOORE, AMY M. "EVALUATION OF THE CURRENT RESISTANCE FACTORS FOR HIGH-STRENGTH BOLTS." University of Cincinnati / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1195432529.
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Bond, Douglas Edward. "Analytical and experimental investigation of a flush moment end-plate connection with six bolts at the tension flange." Thesis, Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/76341.
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An analytical and experimental investigation was conducted to study the six bolt flush moment end-plate connection configuration which is used in steel frame construction. The limit states of plate yielding and bolt fracture were analyzed using yield-line theory to predict endplate thicknesses and a split-tee analogy to develop a method to predict bolt forces. Five experimental tests were conducted on four configurations within a matrix of geometric parameters. The predicted ultimate moment showed good . correlation to the yield moment obtained from the experimental deflection plots. The experimental bolt forces correlated well with the predicted bolt forces when plotted versus the applied moment. Additionally, an equation to model the moment-rotation relationship was developed from a regression analysis to determine the construction type suitable for a given connection configuration. Finally, a method of designing the six-bolt flush end-plate configuration is presented and an example given.Master of Science
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Madireddy, Sandeep Reddy. "Finite Element Modeling of Transverse Post-Tensioned Joints in Accelerated Bridge Construction." DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1302.
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The Accelerated bridge construction (ABC) techniques are gaining popularity among the departments of transportation (DOTs) due to their reductions of on-site construction time and traffic delays. One ABC technique that utilizes precast deck panels has demonstrated some advantages over normal cast-in-place construction, but has also demonstrated some serviceability issues such as cracks and water leakage to the transverse joints. Some of these problems are addressed by applying longitudinal prestressing. This thesis evaluates the service and ultimate capacities in both flexure and shear, of the finite element models of the post-tensioned system currently used by Utah Department of Transportation (UDOT) and a proposed curved-bolt system to confirm the experimental results. The panels were built and tested under negative moment in order to investigate a known problem, namely, tension in the deck concrete. Shear tests were performed on specimens with geometry designed to investigate the effects of high shear across the joint. The curved-bolt connection not only provides the necessary compressive stress across the transverse joint but also makes future replacement of a single deck panel possible without replacing the entire deck. Load-deflection, shear-deflection curves were obtained using the experimental tests and were used to compare with the values obtained from finite element analysis. In flexure, the ultimate load predicted by the finite element model was lower than the experimental ultimate load by 1% for the post-tensioned connection and 3% for the curved-bolt connection. The shear models predicted the ultimate shear reached, within 5% of the experimental values. The cracking pattern also matched closely. The yield and cracking moment of the curved-bolt connection predicted by the finite element model were lower by 13% and 2%, respectively, compared to the post-tensioned connection in flexure.
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Pitrakkos, Theodoros. "The tensile stiffness of a novel anchored blind-bolt component for moment-resisting connections to concrete-filled hollow sections." Thesis, University of Nottingham, 2012. http://eprints.nottingham.ac.uk/13937/.
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The use of hollow section columns in steel construction is presently hindered by the lack of adequate connection technologies. Due to access constraints, standard bolting techniques are difficult to achieve, if not impossible without welding. As an alternative to welding, blind-bolting techniques were developed to provide desirable bolted configurations, allowing hollow column frames to be erected in the same way as open profile column frames. But the current blind-bolting techniques are restricted to the construction of simple connections because of their difficulties in achieving sufficient tensile stiffness. More recently, a novel anchored blind-bolt, labelled the Extended Hollo-bolt (EHB), has been developed at the University of Nottingham; as a modification of the standard Hollo-bolt. For the proposed connection technology, its potential in providing moment-resistance has been assessed successfully. However, the existing data related to the performance of this novel connector in tension is insufficient to permit its design. This work investigates the performance of the EHB blind-bolt under tension loading and focuses on determining, and modelling the stiffness of this novel technology in such a way to enable its application within the component method approach. An extensive experimental programme was devised to collect sufficient component characteristic data to enable the development of an EHB component model. This covered data deals with the overall response of the connector and the individual responses of its contributing elements. A total of 51 experimental pull-out tests and 20 pre-load tests have been performed. The force-displacement behaviour of the investigated joint component was determined under monotonic pull-out testing, where remote video gauge techniques have been adopted to capture the full non-linear response of the component, alongside traditional techniques to confirm the reliability of the data. The test matrix varies the grade and size of the component's internal bolt, the strength of concrete, and the depth of its mechanical anchorage. From the pull-out tests it was identified that the EHB component can ultimately develop the full tensile capacity of its internal bolt. This ultimate failure mode is confirmed for the range of parameters that was covered in this study. Increasing concrete strength had the most enhancing effect on the response of the component. A secondary programme was related to the measurement of pre-load that is induced in the internal bolt of the EHB component at its tightening stage; where pre-load was monitored over a five day period. The test matrix varies the grade and size of its internal bolt, and also considers various bolt batches. It was concluded that the relative level of component pre-load to ultimate strength increased only in the case where higher bolt grades were used. To model the tension behaviour of the EHB component, a mechanical model was developed that is based on an assembly of the component's different sources of deformation. The component model employs idealised springs with tetra-linear characteristics for the elongation of Its Internal bolt element, and springs with tri-linear characteristics for the slip of its expanding sleeves and mechanical anchorage elements. By comparing the predictions of the component model with relevant experimental data, the component model has been shown to be capable of describing the EHB component response with reasonable accuracy; capturing its tensile stiffness and its yielding trend. The accuracy of the component model has also been assessed in exclusion of pre-load effects. It was found that if the level of pre-load Is excluded from the assembly process, this can have highly undesirable effects on the predictions of the component's response. The findings of the supplementary pre-load testing programme assisted greatly in the accuracy of the component model by providing the necessary levels of pre-load. The proposed component model has demonstrated that the behaviour of the EHB component can be modelled by the component method approach; by employing Idealised models for the behaviour of its contributing elements. The validated component model is considered to simulate the tension behaviour of the novel anchored blind-bolt with sufficient fidelity that it can be considered as a benchmark for further studies.
Books on the topic "Bolt tension"
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Undershute, Scott T. Strength and installation characteristics of tension-control bolts. Edmonton, Alta., Canada: Dept. of Civil Engineering, University of Alberta, 1994.
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Kulak, Geoffrey L. A field study of fastener tension in high-strength bolts. Edmonton, Alta: Dept. of Civil Engineering, University of Alberta, 1992.
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Maleev, Vladimir. Installation characteristics of F1852 twist-off type tension control structural bolt/nut/washer assemblies. 2007, 2007.
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Tan, Weiyan. Installation behaviour of ASTM F1852 twist-off type tension control bolts. 2004.
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Guyer, J. Paul. Introduction to Tensioned Rock Bolts for Rock Reinforcement. Independently Published, 2018.
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Programmes Aimed at Technological Self Reliance (India), India. Dept. of Scientific & Industrial Research., and Interaction Meeting on Technological Evaluation in High Tensile Fasteners Industry (1992 : New Delhi, India), eds. Technology evaluation in high tensile fastener industry: A report prepared under Programmes Aimed at Technological Self Reliance (PATSER). New Delhi: Govt. of India, Dept. of Scientific and Industrial Research, Ministry of Science and Technology, 1992.
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The 2006-2011 World Outlook for Aircraft and Aerospace Bolts of at Least 161 KSI Tensile Which Meet Specifications for Flying Vehicles Excluding Plastics. Icon Group International, Inc., 2005.
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Parker, Philip M. The 2007-2012 World Outlook for Aircraft and Aerospace Bolts of Less Than 161 KSI Tensile Which Meet Specifications for Flying Vehicles Excluding Plastics. ICON Group International, Inc., 2006.
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The 2006-2011 World Outlook for Aircraft and Aerospace Bolts of Less Than 161 KSI Tensile Which Meet Specifications for Flying Vehicles Excluding Plastics. Icon Group International, Inc., 2005.
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Parker, Philip M. The 2007-2012 World Outlook for Aircraft and Aerospace Bolts of at Least 161 KSI Tensile Which Meet Specifications for Flying Vehicles Excluding Plastics. ICON Group International, Inc., 2006.
Find full textBook chapters on the topic "Bolt tension"
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Brøns, M., A. Plaugmann, J. J. Thomsen, and A. Fidlin. "Vibration-Based Bolt Tension Estimation for Multi-bolt Joints." In Nonlinear Structures & Systems, Volume 1, 129–33. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-47626-7_21.
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Pichon, Guillaume, Alain Daidie, Adeline Fau, Clément Chirol, and Audrey Benaben. "Cold Working Process on Hard Metal Stacked Assembly." In Lecture Notes in Mechanical Engineering, 41–47. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-70566-4_8.
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AbstractDesigned for aeronautical and automotive applications, the split sleeve cold expansion process is used to improve the fatigue life of bolted metallic parts. Although its application has been well tested on aluminum assemblies, hard metal applications are still being studied. This paper presents experimental results of double bolt joint assemblies under double shear fatigue tests after stacked split sleeve cold expansion. The behaviors of two sizes of assemblies with different degrees of expansion are investigated. S-N curves are the main indicators of this study but thermal aspects are also investigated to observe fretting in the specimens as bolts are preloaded. Bolt tension is a major parameter in assembly regarding fatigue life. Interference between those two phenomena is at the heart of this paper. The first results show that stacked cold expansion has a negative effect on mechanical performances, as it deteriorates the fatigue life of the assembly. However, an examination of these results provides a coherent explanation for the loss of performance that occurs.
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Kim, Noh Yu, and Sang Soon Lee. "Elastic Property Measurement of High-Tension Bolt Based on Mode Converted Ultrasound." In Experimental Mechanics in Nano and Biotechnology, 709–12. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-415-4.709.
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Kawabe, D., C. W. Kim, and Y. Goi. "Bayesian damage detection on full-scale pole structure with anchor bolt tension loosening." In Bridge Safety, Maintenance, Management, Life-Cycle, Resilience and Sustainability, 1011–18. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003322641-121.
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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." In Advances in Fracture and Damage Mechanics VI, 81–84. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-448-0.81.
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Kim, Tae Soo, Han Seung Lee, Sung Ho Tae, and Sung Ok Oh. "Friction Coefficient in High Tension Bolt Joints Using a Zn/Al Metal Spray Corrosion Resistance Method." In Advances in Fracture and Damage Mechanics VI, 465–68. Stafa: Trans Tech Publications Ltd., 2007. http://dx.doi.org/10.4028/0-87849-448-0.465.
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Kagawa, Yuji, and Akihiro Fukushi. "Tension Drop in Cable-Band Bolts on Suspension Bridges." In Bridge Management, 725–35. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4899-7232-3_63.
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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." In Advanced Nondestructive Evaluation I, 240–43. Stafa: Trans Tech Publications Ltd., 2006. http://dx.doi.org/10.4028/0-87849-412-x.240.
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Taylor, Becky. "‘Our Most Foreign Refugees’: Refugees from Vietnam in Britain." In When Boat People were Resettled, 1975–1983, 109–43. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-64224-2_4.
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AbstractBritain’s response to the ‘boat people’ crisis, as Becky Taylor shows in this chapter, had at its heart a contradiction. On the one hand, Margaret Thatcher’s government was keen to be seen as an ally of the US in the Cold War, and still a leader on the international stage. On the other, the arrival of 19,000 Vietnamese ‘boat people’ after 1979 came at a time of growing anti-immigration rhetoric, Britain’s deepest recession for fifty years and just as Thatcher’s New Right government’s marketisation and anti-statist policies were being enacted. This chapter explores how the tension between these different elements shaped Britain’s reception of the ‘boat people’, in particular pointing to the central place of voluntary organisations and multiculturalism in the resettlement programme.
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Chew, Peter A. "Exposing Bot Activity with PARAFAC Tensor Decompositions." In Proceedings of the 2018 Conference of the Computational Social Science Society of the Americas, 25–37. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-35902-7_2.
Full textConference papers on the topic "Bolt tension"
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Shoji, Yasumasa. "An Effect of Gasket Contact Stress Distributions on the Tightness Estimation in Pipe Flange Connections by Finite Element Analyses." In ASME/JSME 2004 Pressure Vessels and Piping Conference. ASMEDC, 2004. http://dx.doi.org/10.1115/pvp2004-2629.
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Recently bolting procedures for flanged connection is one of the important research topics, and several procedures for bolting process are proposed or about to be issued. These procedures are based on bolting experimental and/or analytical results, namely by Finite Element Analyses. Among these researches, only a few are addressing the relationship between bolt tension scatter and gasket contact stress distribution. Bolt tension scatters in nature due to elastic interaction of the bolts as the bolts are tightened one by one. In order to obtain a uniform, or nearly uniform, tension along all the joint bolts, many “rounds” or “passes” are necessary to eliminate this elastic interaction. If the installer does not iterate this tightening process, gasket stress will be distributed undesirably due to the bolt tension scatter. The bolt tension scatter is now mostly calculated using the analysis programs that are developed by research laboratories themselves. In this paper, the author suggests to use a general purpose finite element analysis code for bolt stress, gasket stress and flange stress, which accommodates such advanced functions as bolt pretension and gasket plastic behavior. The author will show that it is possible to analyze the bolt tension, gasket stress and flange stress at the same time using a market sold analysis code, ABAQUS, and examine how many “rounds” are necessary to achieve uniform gasket contact stress. This paper also describes the relationship between the gasket contact stress and the bolt tension scatter, and the effect of internal pressure of piping or pressure vessels. Based on these results, the tightness parameters are estimated and the methods in the standards are verified in the aspect of allowable and achieved leakage.
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van Zyl, Gys. "Determination of Target Bolt Tension for Flanges With Lens Gaskets." In ASME 2017 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/pvp2017-65439.
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A lens gasket is a specific type of metallic ring gasket that is usually only deployed in high pressure gas applications where a high integrity bolted flange joint is required. Lens gaskets are not common in ASME design and there are no ASME rules that guide the design of flanges with lens gaskets, nor are there ASME standards to control lens gasket specifications. Lens gaskets present a special challenge when determining target bolt tension values for flange assembly. For calculating target bolt tension, the gasket seating width is an important parameter. With lens gaskets, the gasket seating width depends on the applied bolt tension, therefore calculation of bolt tension is by nature an iterative process. In these flange joints, the lens gasket has spherical machined surfaces that are in contact with conical gasket seats in the flanges. At low bolt tensions, gasket contact is nearly equivalent to line contact. At high bolt tensions, finite contact widths are developed, sometimes involving plastic deformation of the gasket. This paper will present a method that was developed to determine target bolt tension for a lens gasket bolted flange. Reference will be made to European standards that address lens gaskets, and the results of finite element analysis studies that were used to validate the calculation method will be presented. The successful deployment of the outcome of this work for all the lens gasket flange joints on a plant will be discussed.
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Tsuji, Hirokazu, and Makoto Nakano. "Bolt Preload Control for Bolted Flange Joint." In ASME 2002 Pressure Vessels and Piping Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/pvp2002-1094.
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Tightening method for flange joints proposed by ASME PCC-1 specifies that bolts are tightened by the cross-pattern sequence and tightening torque is raised with several steps. On the other hand, new tightening method has been proposed by Japan BFC committee, in which bolts are tightened in the clockwise-pattern sequence and tightening torque is 100% of the target torque in all steps after an install step with some snug torque. Tightening tests using flanges with various nominal sizes, performed in this study, show that the new tightening method achieves comparable uniformity in bolt preloads and in flange alignment with ASME PCC-1 procedure. This new tightening method is able to reduce both the work volume in the tightening operation and the possibility of human errors like missing the tightening order in it. Step-like increment of the bolt tension under the repeated tightening with small increment of the tightening torque is also discussed. Experimental results show that continuous control of the bolt tension by the repeated tightening is impossible. The step-like increment of the bolt tension is observed in the tightening process of the actual bolted flange joints so that the excessive iteration of the repeated tightening round hardly improves the uniformity of the bolt preloads.
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Noble, Robert. "Design Considerations: Torque or Tension — Advantages and Disadvantages." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-98002.
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To seal effectively gasketed bolted flanged joints require the application of bolt load in a controlled manner. There are two main methods of achieving this — application of bolt load by controlled torque and application of bolt load by controlled tension. The paper considers the practical merits and limitations of each technique under criteria including: Practicality, accuracy, scatter, bolt load or stress, bolt material, bolt length, tool access limitations, cost of tooling, time, safety and ease of understanding. The paper does not seek to recommend one technique over the other but rather to give the joint designer, specifier or tool selector a set of guidelines to ensure the most effective and practical technique is chosen for each joint being designed. Following the recommendations in the paper will allow a designer to recommend a technique that will deliver the best results for the joint based on the principle that long term integrity is more important that short term gain.
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Meisterling, Jesse R. "Joint Integrity Monitoring Using Permanent Ultrasonic Bolt Load Transducers." In ASME 2010 Power Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/power2010-27046.
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Most bolts are designed as tension members, developing a compressive force in a joint (clamp load) that reacts against the external forces of the system: pressure, wind, shock, etc. The main objective of the assembly operation is the creation of the design tension force in the bolt. The degree of success in the assembly process has a direct relationship to the successful operation of the joint system in the field. Until today, the only convenient methods to determine bolt load in the field or on the production floor was to re-apply the tightening tool: wrench or tensioner. The application of the permanent metal/ceramic sputter deposited ultrasonic transducers on large, tension critical fasteners allows for bolt load measurement at any time. This technology delivers ultrasonic direct load measurement while removing all of the inconvenience and variability of conventional ultrasonic techniques. The thin film transducer is small: O̸ 3–5mm, inert, thin (<25um) and permanently attached to the fastener. It is an easy and convenient way to directly measure clamp load in a fastener during production, inspection and in the field: today, tomorrow and next year. The thin-film transducer can be used on a wider range of fastener sizes than possible with conventional hand-held transducers in long-term maintenance applications. The presentation will discuss ultrasonic bolt load measurement theory, and applications with case histories.
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Johnston, Carol. "Effect of Low Pretension on the Fatigue Performance of Large Bolts." In ASME 2022 41st International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/omae2022-78556.
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Abstract Large bolts are used in applications which are subjected to fatigue loads, such as the M72 bolts used in ring flanges of wind turbine towers. Pretension is used as a means of protecting bolts against fatigue loading. Design standards require particular levels of pretension to be applied. For example, 70% of the bolt’s proof strength is often specified. However, in practice, bolts may not be experiencing the required level of pretension. Pretensioning procedure, joint face distortion and in-service relaxation can all influence resulting bolt pretension. However, no guidance is available on the fatigue performance of pretensioned bolts when the pretension is less than the specified value. In this work, a series of tests was carried out using a specially designed test jig, which allowed bolts to be pretensioned and then a fatigue load to be applied to the joint faces. Pretension was applied to the bolts using a hydraulic tensioning tool, and the resulting bolt tension was measured using strain gauges. The pretensions used were intentionally less than the recommended level. The fatigue test results showed that it was necessary to apply a significantly higher level of tension (an overtension) with the hydraulic tool prior to tightening the nut in order to achieve a particular target level of pretension. This overtension was more than two times the target tension. In terms of bolt fatigue performance, as expected, increasing the pretension reduced the load range experienced by the bolts and so increased fatigue life. The mean S-N curve for the pretensioned bolts was similar to and slightly higher than the mean S-N curve obtained from bolts tested without pretension. A relationship was derived, which allows bolt load range to be calculated for a given bolt pretension and applied load range.
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Shoji, Yasumasa. "Self-Loosening Behavior of the Nut Due to Tension Change Considering the Inclination of Bearing Surface." In ASME 2021 Pressure Vessels & Piping Conference. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/pvp2021-62497.
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Abstract Self-loosening behavior is a topic which many researchers are tackling and the principle is coming clearer. Self-loosening occurs mainly when transverse load is applied to the bolt/nut system and the loosening also occurs when such other loads are applied as impact of the bolt (NAS3350 test type) or temperature difference between bolt and nut. The author reproduced the phenomena by using finite element analyses and found the self-loosening is caused by radial relative displacement between bolt and nut threads. On the other hand, some researchers say the self-loosening occur when the tension changes repeatedly while others say it doesn’t. This axial force phenomenon is not yet clear even in experiment. In this paper, the self-loosening phenomenon by the tension change is examined using Finite Element Analyses. The results show that the self-loosening depends on the inclination of the bearing surface. The loosening does not occur when the inclination of the bearing surface is small enough and it occurs when the inclination is large. As the inclination of the bolt head and nut is allowed within the engineering tolerance and flanges rotate when it fastened making the bolt head or nut bearing surface inclination, the self-loosening may happen for any bolts in nature if tension changes repeatedly.
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Nassar, Sayed A., and Mohan Ganganala. "Effect of Load Eccentricity on the Behavior of a Bolted Joint With a Yielded Fastener." In ASME 2009 Pressure Vessels and Piping Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/pvp2009-78135.
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A nonlinear model is proposed for studying the effect of the eccentricity of applied tensile forces on the clamp load loss in bolted joints that were initially tightened beyond the bolt elastic limit. The joint may not have been yielded at initial assembly, however. A closed form solution is obtained for the amount of clamp load loss due to a cyclic separating force. The proposed model takes into account two sources of nonlinearity; namely, the strain hardening behavior of the yielded bolt material as well as the nonlinear deformation behavior of the clamped plates under an external separating load. After the initial tightening of the fastener past its elastic limit, the subsequent application of a tensile separating force on the joint tends to increase the fastener tension in a nonlinear fashion, and simultaneously reduce the clamping force in the bolted joint from its initial value. Upon the removal of the cyclic tensile load, the bolted joint system reaches a new equilibrium point between the residual fastener tension, and the joint clamping force. At the new equilibrium point, the fastener tension is reduced from its preload due to its plastic elongation; simultaneously, a partial-yet permanent-loss in the clamp load level takes place. Excessive clamp load loss may lead to joint leakage, fastener loosening, or fatigue failure. For a known amplitude of the external cyclic tensile load, the increase in bolt tension and corresponding reduction in the joint clamp load are highly sensitive to the eccentricity of the tensile load (from the bolt center). Variables studied include the eccentricity value of the separating load, the rate of strain hardening of the bolt material, compressive and tensile stiffnesses of the clamped plates, bolt stiffness, bolt preload, and the magnitude of the separating tensile load.
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Alkelani, Ali A., Sayed A. Nassar, and Basil A. Housari. "A Novel Formulation of Elastic Interaction in Gasketed Bolted Joints." In ASME 2007 Pressure Vessels and Piping Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/pvp2007-26084.
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A novel mathematical model is proposed for studying elastic interaction in gasketed bolted joints. The model predicts the tension changes in tightened bolts due to the subsequent tightening of other bolts in the joint. It also predicts the final clamp load distribution after the completion of joint tightening. The model is used to investigate the effect of various factors on the elastic interaction phenomenon; factors include the gasket thickness, bolt spacing, fastener preload level, and the tightening sequence of various bolts. Experimental verification is provided for the validation of the mathematical model. Experimental and analytical results are presented and discussed. The proposed model provides good prediction of the final clamp load in the joint. Moreover, the proposed model may be used to determine the level of initial bolt tension in each bolt that would be necessary to achieve the desired level of uniform clamp load in the joint at initial assembly.
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Tsuji, Hirokazu, and Kazuo Maruyama. "Estimation of Yield Clamping Force Based on Rigid-Plastic Model." In ASME 1999 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/imece1999-1195.
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Abstract Yield clamping force of a bolt in plastic region tightening depends on yield point load of the bolt under combined loads of axial tension and thread torque induced by the tightening process. A new estimation method using interaction curve for yield is proposed, which is applied to the yield clamping force and maximum additional tension under external force. This estimation method utilizes the general yield criterion based on the rigid-plastic solution for combined loads of tension and torsion. The yield of the bolt is expressed by the point of the intersection between the interaction curve and loading path of the bolt in tightening or external loading. Considering the coefficient of friction at the flank of the thread and the residual thread torque after tightening, yield clamping force and maximum additional tension are obtained respectively by the simple formulas. The yield clamping force and the maximum additional tension of the bolt are examined experimentally by a combined load testing machine which can apply combined tensile and torsional loads on the threaded portion of the bolt. Estimated values by the proposed method shows good agreement with the experimental results. The proposed estimation method is superior to the conventional one which takes into account only the local yield criterion. Finally, the target zones of initial clamping force controlled by elastic region tightening, yield point tightening and plastic region tightening are examined. Usefulness of the yield clamping force is demonstrated based on the rigid-plastic model.
Reports on the topic "Bolt tension"
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VandeKraats, J. D., and S. O. Watson. Direct laboratory tensile testing of select yielding rock bolt systems. Office of Scientific and Technical Information (OSTI), August 1996. http://dx.doi.org/10.2172/367133.
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Moore, Keegan J., and Matthew Robert Brake. A Reduced Order Model of Force Displacement Curves for the Failure of Mechanical Bolts in Tension. Office of Scientific and Technical Information (OSTI), December 2015. http://dx.doi.org/10.2172/1234813.
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TENSILE BEHAVIOR OF T-STUB SUBJECTED TO STATIC AND DYNAMIC LOADS. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.313.
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To study the tensile behavior of T-stubs with various design parameters under different loading scenarios, uniaxial static and dynamic tensile tests were carried out. The effects of flange thickness, bolt preload, bolt strength and loading conditions were discussed. The failure modes observed under different conditions were presented. Besides, the load-displacement response was analyzed in detail. The experimental results showed that the bolt preload only affected the initial stiffness of the specimens, and smaller flange thickness and lower bolt strength would result in unfavorable performance of T-stubs. Under dynamic loading scenarios, the test specimens showed greater resistance but limited deformation capacity compared to the static ones. Furthermore, it was observed that the ductility would be seriously reduced if brittle failure, such as bolt or weld fracture occurred which is recommended to be avoided in structural design.
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ULTIMATE STRENGTH, DUCTILITY AND FAILURE MODE OF HIGH-STRENGTH FRICTIONAL BOLTED JOINTS MADE OF HIGH STRENGTH STEEL. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.239.
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Further structural rationalization of steel bridge such as weight reduction of members is realizable by utilizing high strength steel. However, due to the high yield-to-tensile strength ratio, failure of connected members occur before the members in gross area has been plastic-deformed sufficiently. In this study, tensile tests of frictional bolted joint which varies geometrical configurations and grades of plate and bolts, were conducted to compare failure modes of high strength steel joint and mild steel joint and to investigate the relationship among ultimate strength, ductility and failure mode. From obtained results, failure modes of high strength steel joint were the same as those of mild steel joint and can be almost classified with the respective ratios of net cross-section failure resistance and plate shear failure resistance to bolt shear failure resistance. Ultimate resistance and ductility became highest in the case of split failure mode where these ratios were about 1.0 and they increased as the ratios decreased. Therefore, it’s concluded that these ratios should be less than 1.0 to induce split failure mode for making high strength steel joint be broken after the member has been plastic-deformed sufficiently.
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SIMPLIFIED MODELLING OF NOVEL NON-WELDED JOINTS FOR MODULAR STEEL BUILDINGS. The Hong Kong Institute of Steel Construction, December 2021. http://dx.doi.org/10.18057/ijasc.2021.17.4.10.
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Prefabricated modular steel (PFMS) construction is a more efficient and safe method of constructing a high-quality building with less waste material and labour dependency than traditional steel construction. It is indeed critical to have a precise and valuable intermodular joining system that allows for efficient load transfer, safe handling, and optimal use of modular units' strength. Thus, the purpose of this study was to develop joints using tension bolts and solid tenons welded into the gusset plate (GP). These joints ensured rigid and secure connectivity in both horizontal and vertical directions for the modular units. Using the three-dimensional (3D) finite element (FE) analysis software ABAQUS, the study investigated the nonlinear lateral structural performance of the joint and two-storey modular steel building (MSB). The solid element FE models of joints were then simplified by introducing connectors and beam elements to enhance computational efficiency. Numerous parameters indicated that column tenons were important in determining the joint's structural performance. Moreover, with a standard deviation (SD) of 0.025, the developed connectors and beam element models accurately predicted the structural behaviour of the joints. As a result of their simplification, these joints demonstrated effective load distribution, seismic performance, and ductility while reducing computational time, effort, and complexity. The validity of the FE analysis was then determined by comparing the results to the thirteen joint bending tests performed in the reference.