• 제목/요약/키워드: axial force

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분기부(分岐部) 장대(長大)레일화시의 축력거동특성(軸力擧動特性) 해석(解析) (The Parameter Study on the Characteristics of Axial Force in Turnout with Continuous Welded Rail)

  • 김두환;고상훈
    • 한국구조물진단유지관리공학회 논문집
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    • 제5권2호
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    • pp.163-174
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    • 2001
  • This paper is to study the characteristics of axial force behavior that operates to the part of turnout when it makes the turnout and the continuous welded rail unifying. The study is to model by using the 50kgN rail No. 15 turnout used in the domestic national railway and the UIC60 rail No. 18 turnout used in the rapid transit railway as the finite elements for analyzing the axial force behavior of the turnout by the continuous welded rail. It is to analyze the characteristics of behavior according to the change of creep resistance, ballast resistance and the change of parameter valuables of heel joint by the axial force simulation in making the continuous welded rail and then, it is to present the result. As the result of research on the parameter valuables through the analysis, it shows that the maximum axial force of turnout by the continuous welded rail are largely subordinated to the maximum resistance of heel joint and the fitting devices than the ballast resistance. Also it shows that the maximum axial force produced changes a lot according to the characteristics of creep resistance of the fitting part and the ballast resistance.

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마찰을 고려한 이중 오프셋 등속조인트의 축력 해석에 관한 연구 (Analytic Study on the Axial Forces of a Double Offset Constant Velocity Joints in Consideration of Friction Effect)

  • 배병철
    • 한국자동차공학회논문집
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    • 제16권2호
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    • pp.120-127
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    • 2008
  • The constant velocity joint(CVJ) used for transmitting torque to the front wheels is an important part in automotive drive system. There are several types of constant velocity joints. Typically, they are classified by fixed and plunging constant velocity joints. The axial force generated in plunging constant velocity joints influences significantly the noise, vibration and harshness. For heaps of time, many constant velocity joint markers have been studying and developing a valid method to reduce the axial force and extensive tests have been carried out on rigs. This paper presents the analysis method to predict the axial force of a double offset constant velocity joint(DOJ), a kind of plunging constant velocity joint, and the influence of ball-cage dimension tolerance on the axial force.

공작기계 주축 테이퍼 결합부 정강성에 관한 연구 (A Study on the Static Stiffness in the Main Spindle Taper of Machin Tool)

  • 김배석;김종관
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2001년도 춘계학술대회 논문집(한국공작기계학회)
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    • pp.149-154
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    • 2001
  • This paper presents the experimental study of the static stiffness for the BT Shank(7/24 Long Taper) and the HSK Tool Shank(1/10 Short taper). The static stiffness test was performed under different experimental conditions. The results obtained are as follows ; As known in the analysis results of the Load-Deflection diagram of the 7/24 Test tool shank, it is turned out that the diagram is a linear characteristics without regard to axial drawing force and according as the axial drawing force get to the 6kN, the static stiffness of the shank increase linearly. Thus the effective axial drawing force which maintains the static stiffness of the Main spindle taper of Machine Tool is larger than 6kN. It is found that the Load-Deflection diagram with 6kN of drawing force in the 1/10 Test tool shank is characterized by non-linear. But according as the axial drawing force is increasing by the 8kN, the diagram is characterized by linear. And increasing amount of deflection is about 60%. Therefore commendable axial drawing force is larger than 8kN. As a result, considering that the actual drawing force of the Machining Center is about 1300kgf and axial drawing force 12kN is equivalent amount as a 1220kgf, it is turned out that 1/10 Test tool shank superior to 7/24 Test tool shank in the static stiffness.

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Experimental axial force identification based on modified Timoshenko beam theory

  • Li, Dong-sheng;Yuan, Yong-qiang;Li, Kun-peng;Li, Hong-nan
    • Structural Monitoring and Maintenance
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    • 제4권2호
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    • pp.153-173
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    • 2017
  • An improved method is presented to estimate the axial force of a bar member with vibrational measurements based on modified Timoshenko beam theory. Bending stiffness effects, rotational inertia, shear deformation, rotational inertia caused by shear deformation are all taken into account. Axial forces are estimated with certain natural frequency and corresponding mode shape, which are acquired from dynamic tests with five accelerometers. In the paper, modified Timoshenko beam theory is first presented with the inclusion of axial force and rotational inertia effects. Consistent mass and stiffness matrices for the modified Timoshenko beam theory are derived and then used in finite element simulations to investigate force identification accuracy under different boundary conditions and the influence of critical axial force ratio. The deformation coefficient which accounts for rotational inertia effects of the shearing deformation is discussed, and the relationship between the changing wave speed and the frequency is comprehensively examined to improve accuracy of the deformation coefficient. Finally, dynamic tests are conducted in our laboratory to identify progressive axial forces of a steel plate and a truss structure respectively. And the axial forces identified by the proposed method are in good agreement with the forces measured by FBG sensors and strain gauges. A significant advantage of this axial force identification method is that no assumption on boundary conditions is needed and excellent force identification accuracy can be achieved.

신뢰성 이론을 이용한 고강도콘크리트 구조물의 축력-모멘트관계에 있어서의 해석방법에 대한 평가 (The Estimation of Analytical Method for Axial Force-Moment Relationships of High-Strength Concrete Structures using Reliability Theory)

  • 최광진;장일영;송재호;홍원기
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 봄 학술발표회논문집(II)
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    • pp.447-454
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    • 1998
  • The main object of the study is that axial force-moment relationships for high strength concrete structures using reliability theory(Linear statstical method, Monte Carlo Simulation) including probability conception. And mean stress factors and centroid factors proposed to high strength concrete structures using reliability theory(Linear statstical method, Monte Carlo Simulation). Finally, The established experimental data for axial force-moment relationships are compared to the analytical data(data for Linear statstical method and Monte Carlo Simulation) for axial force-moment relationships in this analytical method.

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신뢰성이론을 이용한 고강도콘크리트 구조물의 축력-모멘트관계에 관한 해석적인 연구 (The Analytical Study of Axial Force-Moment Relationships for High Strength Concrete Structures using Reliability Theory)

  • 최광진;홍원기;장일영;송재호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.500-506
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    • 1997
  • The main object of the study is that axial force-moment relationships for high strength concrete structures using reliability theory probability conception. And mean stress factors and centroid factors proposed to high strength concrete structures using reliability theory. Finally, the established experimental data for axial force-moment relationships are compared to the analytical data for the axial force-moment relationships in this analytical method.

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Effect of the height of SCSW on the optimal position of the stiffening beam considering axial force effect

  • Azar, B. Farahmand;Hadidi, A.;Khosravi, H.
    • Structural Engineering and Mechanics
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    • 제41권2호
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    • pp.299-312
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    • 2012
  • Stiffened coupled shear walls (SCSW) are under axial load resulting from their weight and this axial load affects the behavior of walls because of their excessive height. In this paper, based on the continuum approach, the optimal position of the stiffening beam on the stiffened coupled shear walls is investigated considering the effect of uniformly distributed axial loads. Moreover, the effect of the height of stiffened coupled shear walls on the optimal position of the stiffening beam has been studied with and without considering the axial force effect. A computer program has been developed in MATLAB and numerical examples have been solved to demonstrate the reliability of this method. The effects of the various flexural rigidities of the stiffening beam on the internal forces and the lateral deflection of the structure considering axial force effect have also been investigated.

RC 부재의 전단거동에 미치는 축력의 영향에 대한 연구 (Effect of Axial Force on Shear Behavior in Reinforced Concrete Beams)

  • 정제평;김대중;염환석;김우
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
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    • pp.264-267
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    • 2004
  • It is well known that axial tension decreases the shear strength of RC beams without transverse reinforcement, and axial compression increases the shear resistance. What is perhaps not very well understood is how much the shear capacity is influenced by axial load. RC beams without shear reinforcement subjected to large axial compression and shear may fail in a very brittle manner at the instance of first diagonal cracking. As a result, a conservative approach should be used for such members. According to the ACI Code, the concrete contribution is calculated by effect of axial force and the vertical force in the stirrups calculated by $45^{\circ}$ truss model. This study was performed to examine the effect of axial force in reinforced concrete beams.

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자동차용 등속조인트의 AXIAL FORCE와 VEHICLE SHUDDER(I) (Vehicle Shudder Associated with Axial Thrust Force of C.V.Joint For Automobile)

  • 오승탁
    • 한국자동차공학회논문집
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    • 제4권2호
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    • pp.198-208
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    • 1996
  • The plunge joints of C.V. Joint for vehicle tend to produce a cyclic axial disturbance at a frequency of three of six times shaft speed, in which this distrubance caused by internal frictional effect is related to joint angle, rotational speed, torque, and joint size. This principal axial thrust force might make vehicle shuddered when coinciding with vehicle frequency of tranverse direction, and be one of reasons to have driver feel uncomfortable, unesay, while driving vehicle. The paper makes analysis of axial thrust force & vehicle shudder through computer simulation, comparing the result with experimental data, and reviewing the effect by changing of variables such as dimensions and driving conditions.

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내연기관 크랭크축계 종진동에 관한 연구 (제2보 : 크랭크축계 종진동의 공진진폭계산) (The Axial Vibration of Internal Combustion Engine Crankshaft (Part II. Resonant Amplitudes Calculation of the Crankshaft Axial Vibration))

  • 김영주;고장권;전효중
    • Journal of Advanced Marine Engineering and Technology
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    • 제6권2호
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    • pp.69-91
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    • 1982
  • The major factors which affect the crankshaft axial vibration are such items as the axial stiffness and mass of crankshaft, the thrust block stiffness, the propeller's entrained water and the exciting and damping forces of engine, propeller and shafting. Among above mentioned items, the axial stiffness and mass of crankshaft, thrust block stiffness and propeller's entrained water were treated in detail in part I, and so in this paper, the rest of above items will be studied. The exciting forces of crankshaft axial vibration are generated mainly from the gas explosion pressure of cylinder, the thrust fluctuation of propeller, and sometimes the torsional vibration of crankshaft induces the crankshaft axial vibration. As for the propeller thrust fluctuation, its harmonic components can be fairly exactly calculated from the experimental results of propeller in the towing tank, but as the calculation process is rather tedious and laborious, the empirical values are ordinarily used. On the other hand, the table of harmonic components of gas pressure has been already published by major slow speed diesel engine makers, but the axial thrust conversion factor of radial force is not unknown yet, and as its estimated value is unreliable, the axial vibration force of gas pressure is uncertain. As the calculation of damping force is very complicated and it includes some uncertain factors, the thoretically estimated amplitudes of axial vibration are much more incorrect in comparison with those of torsional vibrations. Authors have paid special attentions to deriving the theoretical calculation formula of axial conversion factor of radial force and damping force of crankshaft axial vibration and developed a computer program to calculate resonance amplitudes and additional stresses of crankshaft axial vibrations. Also, to check the reliability of the developed computer program, the axial vibrations of three ships' propulsion shaftings were analyzed and their results were compared with those of measured values and makers' results.

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