A Study to Predict Fatigue Limits of Bolted Joints under Transverse Vibration

Hashimura, Shinji; Kurakake, Yu

doi:10.4271/2010-01-0964

Cited by 3 publications

(2 citation statements)

References 5 publications

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“…The friction coefficient between contact surfaces was µ=0. 25. The left clamped plate was constrained as shown in Fig.…”

Section: Finite Element Modelmentioning

confidence: 99%

“…Fukuoka et al reproduced the spiral shape of screw thread to conduct FEM analysis and found the characteristics of self-loosening, fatigue strength, and load change (21)(22)(23) . Hashimura 5 et al clarified the difference of occurrence conditions of self-loosening and fatigue destruction when bolted joints are subjected to axial transverse vibration to show the method to evaluate fatigue destruction mechanism as well as fatigue strength in the case that bolted joints receive axial transverse vibration (24,25) . Thus a lot of self-loosening studies have been conducted in the case that bolted joints are subjected to axial transverse load.…”

Section: Introductionmentioning

confidence: 99%

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Influences of Various Parameters on Shear Stiffness of Bolted Joint Subjected to Shear Load

Murai¹,

Watanabe²,

Fukuda³

et al. 2023

Preprint

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Multi-material structures have been required to reduce weight of vehicles in order to improve fuel efficiencies. To realize multi-material structures effectively, we have to select not only the optimum material for each structure but also the optimum joining techniques for each joint. Bolted joints are one of the most popular methods to join dissimilar materials. Various characteristics for the bolted joints had been revealed in the literatures. Especially self-loosening characteristics of bolted joints subjected to shear cyclic load have been still investigated. However it has not been sufficiently investigated which parameters effect on shear stiffness of bolted joints which is subjected to shear load. When two plates are joined by a bolt and a nut, it is important for functionally designing machines to know if the shear stiffness of the joining point is the same as the plate stiffness or not and if the stiffness changes or not. In this study, we have revealed experimentally and analytically the shear stiffness characteristics of bolted joints and which parameters determine the shear stiffness. Washers with different contact areas to the clamped plates were used in the experiments. The results showed that the shear stiffness of bolted joints increases with an increase in the contact area size between washers and clamped parts. The result indicates that the shear stiffness of bolted joint is mainly determined by the bending stiffness that is an easiness of bolted joints to rotate due to shear tensile force rather than the clamping force. But if the slippage occurs between the clamped plates, the shear stiffness of bolted joint markedly decreases. The results also showed that the tensile force with which the clamped plates begin to slip between them depends on the clamp force of bolted joints and the contact area size between the clamped plate and the washers.

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“…The friction coefficient between contact surfaces was µ=0. 25. The left clamped plate was constrained as shown in Fig.…”

Section: Finite Element Modelmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Influences of Various Parameters on Shear Stiffness of Bolted Joint Subjected to Shear Load

Murai¹,

Watanabe²,

Fukuda³

et al. 2023

Preprint

Self Cite

View full text Add to dashboard Cite

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Influences of various parameters on shear stiffness of bolted joints subjected to shear load

Murai

Watanabe

Fukuda

et al. 2023

Int J Adv Manuf Technol

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Parameters which affect shear stiffness characteristics of bolted joints subjected to shear load should be elucidated in order to design mechanical structures for functionality focusing not only on their strength and self-loosening but also on their shear stiffness. In this study, we have both experimentally and analytically investigated the behaviors of a bolted joint subjected to shear load and primary parameters which determine the shear stiffness characteristics of bolted joints. The experiments have been conducted applying the shear load four times repeatedly on clamped plates of a bolt/nut assembly with washers. We measured the shear stiffness of bolted joints and the shear load at which the slippage started to occur between the clamped plates. Four types of washers were used in the experiments with different contact areas on the clamped plates in order to reveal the effect of contact area of washers. We also conducted FE analysis under the same conditions. As the results, it was seen that the shear stiffness slightly increased with an increase in the clamp force of bolted joint. The shear stiffness was not influenced by the number of loading cycles. It was also seen that the amount of rotational deformation in the bolted joint depended on the slippage between the clamped plates. Although the rotation deformation was very small until the slippage occurrence, the rotational deformation remarkably increased after the slippage occurred. In general, it is well-known that the joining portion of lap jointed plates by spot welding, for example, slightly and rotationally deformed, but it has never been elucidated that the inclination angle due to the rotational deformation depends on the slippage between the clamped plates in the bolted joint. It was also seen that the shear stiffness until the slippage occurrence increased with an increase in the contacting surface area between the clamped plates. Although we investigated the effect of surface roughness of the clamped plates only in the experiments, we cannot clearly reveal its effect on the shear stiffness. But it is seen from the FE analysis result that the friction coefficient between clamped plates had a slight influence on the shear stiffness. The result shows that the shear stiffness of bolted joint mainly depends not only on the slip resistance between the clamped plates but also on increase of the contact surface between the washers and clamped plates. The results can be applied in order to control the shear stiffness of lap-jointed plates by spot welding and so on.

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Low Friction Coating for High Temperature Bolted Joints in IC Engines

Zhang¹,

Wang²,

Barber³

et al. 2023

SAE Technical Paper Series

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<div class="section abstract"><div class="htmlview paragraph">The IC engine still plays an important role in global markets, although electrified vehicles are highly demanded in some markets. Emission requirements for stoichiometric operation are challenging. This requires the bolted joints for turbo, EGR (Exhaust Gas Recirculation) and exhaust manifold to work under much higher temperature than before. How to avoid fastener breakage due to bolt bending caused by cyclic changes of the thermal conditions in engines is a big challenge. The temperatures of the components in the exhaust, EGR (Exhaust Gas Recirculation) and turbo systems change from ambient temperature to about 800 ~ 1000 °C when engines run at peak power with wide-open throttle. The temperature change induces catastrophic cyclic bending and axial strain to the fasteners. This research describes a method to reduce the cyclic bending displacement in the fasteners using a low friction washer. Mathematical modeling and FEA methods have been employed to specify the design space based on the engine operating conditions. A series of tribological bench tests were conducted to evaluate different coatings on the washer under room temperature and up to 600 °C. A sensitivity study has also been done to identify the factors that affect the coefficient of friction (CoF). A multi-layer coating has been found to be able to provide a low coefficient of friction under high temperature and high pressure. It meets the design requirements and has been validated by engine dyno tests on the exhaust system.</div></div>

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A Study to Predict Fatigue Limits of Bolted Joints under Transverse Vibration

Cited by 3 publications

References 5 publications

Influences of Various Parameters on Shear Stiffness of Bolted Joint Subjected to Shear Load

Influences of Various Parameters on Shear Stiffness of Bolted Joint Subjected to Shear Load

Influences of various parameters on shear stiffness of bolted joints subjected to shear load

Low Friction Coating for High Temperature Bolted Joints in IC Engines

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