• Title/Summary/Keyword: Plane bearing

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An Improvement of the Stability of Plane Journal Bearing using Leaf Spring Damper (겹판스프링댐퍼를 이용한 저어널베어링의 안정성 향상)

  • 김종수;최영준;제양규
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.06a
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    • pp.87-92
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    • 2000
  • In order to improve the instability of Plane journal bearing, it is introduced the leaf spring damper(LSD). The effects of dynamic characteristics of LSD on the stability of a plane journal bearing were investigated theoretically. The improvements on the stability of a plane journal bearing with LSD. are compared with the results of a floating ring journal bearing and of journal bearing without LSD. It found that a plane journal bearing with LSD will be an effective way in the improvement on the stability of rotor system.

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An Improvement of the Stability of Plane Journal Bearing using Leaf Spring Damper (겹판스프링댐퍼를 이용한 저어널베어링의 안정성 향상)

  • 김종수;최영준;제양규
    • Tribology and Lubricants
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    • v.17 no.3
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    • pp.179-184
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    • 2001
  • In order to improve the instability of plane journal bearing, it is introduced the leaf spring damper(LSD). The effects of dynamic characteristics of LSD on the stability of a plane Journal bearing were investigated theoretically. The improvements on the stability of a plane journal bearing with LSD are compared with the results of a floating ring journal bearing and of journal bearing without LSD. It found that a plane journal bearing with LSD will be an effective way in the improvement on the stability of rotor system.

An Experimental Study on Improvement of the Stability of Plane Journal Bearing using Leaf Spring Damper (겹판스프링댐퍼를 이용한 저어널베어링의 안정성 향상에 관한 실험적연구)

  • 최영준;김종수;제양규
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.06a
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    • pp.153-158
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    • 2000
  • The purpose of present paper is to prove an improvement on stability of plane Journal bearing due to the leaf spring damper(LSD) experimentally A flexible rotor system is designed and manufackuea in order to generate oil whip instability of journal bearing at relative lower rotating speed. Vibration amplitude and instability onset speeds are investigated for a conventional plane journal bearing and plane journal bearing with LSD. To investigate the damping effects of LSD on stability of bearing, experiments are also conducted on the leaf spring dampers with and without working oil. It is found that the leaf spring damper can considerably increase the instability onset speed of a plane journal bearing.

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An Experimental Study on Improvement of the Stability of Plane Journal Bearing using Leaf Spring Damper (겹판스프링댐퍼를 이용한 저어널베어링의 안정성 향상에 관한 실험적연구)

  • 최영준;김종수;제양규
    • Tribology and Lubricants
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    • v.17 no.3
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    • pp.185-190
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    • 2001
  • The purpose of present paper is to prove an improvement on stability of plane journal bearing due to the leaf spring damper (LSD) experimentally. A flexible rotor system is designed and manufactured, in order to generate oil whip instability of journal bearing at relative lower rotating speed. Vibration amplitude and instability onset speeds are investigated for a conventional plane journal bearing and plane journal bearing with LSD. To investigate the damping effects of LSD on stability of bearing, experiments are also conducted on the leaf spring dampers with and without working oil. It is found that the leaf spring damper can considerably increase the instability onset speed of a plane Journal bearing.

Effects of Asymmetry of Bearing Damper Stiffness on the Stability of Rotors (베어링 지지댐퍼 강성의 비대칭이 회전체 동특성에 미치는 영향)

  • 제양규
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.05a
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    • pp.100-106
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    • 2003
  • In order to improve the instability of a plane journal bearing, the leaf spring dampers (LSD) are introduced. The effects of LSD on the stability of a plane journal bearing are investigated theoretically. The stability of a plane journal bearing with LSD are compared with the results of a plane journal bearing without LSD. And the effects of the asymmetry of the stiffness of the leaf spring damper on the stability of rotors are also investigated.

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Micro modelling of masonry walls by plane bar elements for detecting elastic behavior

  • Doven, Mahmud Sami;Kafkas, Ugur
    • Structural Engineering and Mechanics
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    • v.62 no.5
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    • pp.643-649
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    • 2017
  • Masonry walls are amongst the oldest building systems. A large portion of the research on these structures focuses on the load-bearing walls. Numerical methods have been generally used in modelling load-bearing walls during recent years. In this context, macro and micro modelling techniques emerge as widely accepted techniques. Micro modelling is used to investigate the local behaviour of load-bearing walls in detail whereas macro modelling is used to investigate the general behaviour of masonry buildings. The main objective of this study is to investigate the elastic behaviour of the load- bearing walls in masonry buildings by using micro modelling technique. In order to do this the brick and mortar units of the masonry walls are modelled by the combination of plane truss elements and plane frame elements with no shear deformations. The model used in this study has fewer unknowns then the models encountered in the references. In this study the vertical frame elements have equivalent elasticity modulus and moment of inertia which are calculated by the developed software. Under in-plane static loads the elastic displacements of the masonry walls, which are encountered in literature, are calculated by the developed software, where brick units are modelled by plane frame elements, horizontal joints are modelled by vertical frame elements and vertical joints are modelled by horizontal plane truss elements. The calculated results are compatible with those given in the references.

Enhancement of in-plane load-bearing capacity of masonry walls by using interlocking units

  • Kayaalp, Fatma Birinci;Husem, Metin
    • Earthquakes and Structures
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    • v.22 no.5
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    • pp.475-485
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    • 2022
  • This paper presents a comparative experimental study on structural behavior of the interlocking masonry walls under in-plane cyclic loading. The main purpose of this study is to increase lateral load-bearing capacities of masonry walls by using interlocking units. The interlocking units were designed by considering failure modes of masonry walls and produced using lightweight foamed concrete. To this end, three masonry walls which are hollow, fully grouted, and reinforced were constructed with interlocking units. Also, a traditional masonry brick wall was built for comparison reasons. The walls were tested under in-plane cyclic loading. Then, structural parameters of the walls such as lateral load bearing and total energy dissipation capacities, ductility, stiffness degradation as well as failure modes obtained from the tests were compared with each other. The results have shown that the walls with the interlocking units have better structural performance than traditional masonry brick walls and they may be used in the construction of low-rise masonry structures in rural areas to improve in-plane structural performance.

A Four Pole, Double Plane, Permanent Magnet Biased Homopolar Magnetic Bearing with Fault-Tolerant Capability

  • Na, Uhn-Joo
    • Journal of the Korean Society of Industry Convergence
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    • v.24 no.6_1
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    • pp.659-667
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    • 2021
  • This paper develops the theory for a novel fault-tolerant, permanent magnet biased, 4-active-pole, double plane, homopolar magnetic bearing. The Lagrange Multiplier optimization with equality constraints is utilized to calculate the optimal distribution matrices for the failed bearing. If any of the 4 coils fail, the remaining three coil currents change via a novel distribution matrix such that the same opposing pole, C-core type, control fluxes as those of the un-failed bearing are produced. Magnetic flux coupling in the magnetic bearing core and the optimal current distribution helps to produce the same c-core fluxes as those of unfailed bearing even if one coil suddenly fails. Thus the magnetic forces and the load capacity of the bearing remain invariant throughout the failure event. It is shown that the control fluxes to each active pole planes are successfully isolated. A numerical example is provided to illustrate the new theory.

Investigations on the bearing strength of stainless steel bolted plates under in-plane tension

  • Kiymaz, G.
    • Steel and Composite Structures
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    • v.9 no.2
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    • pp.173-189
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    • 2009
  • This paper presents a study on the behavior and design of bolted stainless steel plates under in-plane tension. Using an experimentally validated finite element (FE) program strength of stainless steel bolted plates under tension is examined with an emphasis on plate bearing mode of failure. A numerical parametric study was carried out which includes examining the behavior of stainless steel plate models with various proportions, bolt locations and in two different material grades. The models were designed to fail particularly in bolt tear-out and material piling-up modes. In the numerical simulation of the models, non-linear stress-strain material behavior of stainless steel was considered by using expressions which represent the full range of strains up to the ultimate tensile strain. Using the results of the parametric study, the effect of variations in bolt positions, such as end and edge distance and bolt pitch distance on bearing resistance of stainless steel bolted plates under in-plane tension has been investigated. Finally, the results obtained are critically examined using design estimations of the currently available international design guidance.

A Study on the Load Carrying Capacity and Equivalence Friction Coefficient of a Textured Plane Bearing with Semi-spherical Dimples and Semi-ellipsoidal Dimples (반구형 및 반타원형으로 텍스처링된 평면 베어링의 부하지지능력과 등가마찰계수에 대한 해석)

  • Lee, Soo-Young;Kim, Pil-Kee;Seok, Jong-Hyuk;Seok, Jong-Won
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.5
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    • pp.741-746
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    • 2012
  • The increase of energetic efficiency in plane bearing is getting more important in the transfer mechanism of semi-conductor and display panel manufacturing processes. To accomplish this objective, the technique of surface texturing on bearing surface has recently emerged as one of the most effective candidates. In this study, the effects of various pattern parameters on two bearing performance indices(load carrying capacity and effective friction coefficient) are investigated through a semi-analytic method, i.e., the 2-dimensional Reynolds equation incorporated into the finite difference scheme. Here, cavitation effect is also taken into account by employing an appropriate numerical scheme. In this study, the patterns in the textured surface are composed of a series of semi-spheres or semi-ellipsoids in shape. The effects of their size and number density on the performance indices are examined through the performance of various numerical experiments. Also, the effects of the anisotropy of the semi-ellipsoidal pattern on the bearing's lubrication characteristics are investigated and discussed.