• Title/Summary/Keyword: rotary function

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Analysis of Vibration for the Pre-twisted Beam Considering the Effect of Rotary Inertia Using the Transfer Matrix Mathod (전달행렬법을 이용하여 비틀림 각과 회전관성을 고려한 보의 진동해석)

  • Lee, Jung Youn
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.26 no.2
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    • pp.217-224
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    • 2016
  • In this study, a transfer matrix method (TMM) for a twisted uniform beam considering the effect of rotary inertia is developed, and the differential equation and the displacements and forces are derived from Hamilton's principle. The particular transfer matrix is derived by applying the distributed mass and transcendental function while using a local coordinate system. In addition, the results obtained from this method are independent for a number of subdivided elements, and this method can determine the exact solutions for the free vibration characteristics of a twisted uniform Rayleigh beam. To validate the accuracy of the proposed TMM, the computed results are compared with those reported in the existing literature, and the comparison results indicate notably good agreement. In addition, the method is used to investigate the effects of rotary inertia for a twisted beam.

The Postprocessor Technology of for 5-axis Control Machining (5축가공을 위한 포스트프로세서 기술)

  • Jung, Hyoun-Chul;Hwang, Jong-Dae;Kim, Sang-Myung;Jung, Yoon-Gyo
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.10 no.2
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    • pp.9-15
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    • 2011
  • In order to develop a practical postprocessor for 5-axis machining, the general equations of numerically controlled (NC) data for 5-axis configurations with not only non-orthogonal rotary axes but also orthogonal rotary axes were exactly expressed by the inverse kinematics, and a Windows-based postprocessor written in Visual Basic was developed according to the proposed algorithm. The developed postprocessor is a general system that suitable for all kinds of 5-axis machine tool with orthogonal and non-orthogonal rotary axes. Through implementation of the developed postprocessor and verification by a cutting simulation and machining experiment, the effectiveness of the proposed algorithm is confirmed. Compatibility is improved by allowing exchange of data formats such as rotational tool center position (RTCP) controlled NC data, vector post NC data, and program object file (POF) cutter location (CL)data, and convenience is increased by adding the function of work-piece origin offset. Consequently, the technology of practical post-processor for 5-axis machining is developed.

A Study on Hydro-mechanical Behaviors of Rock Joints using Rotary Shear Testing Apparatus (회전식 전단시험기를 이용한 암석절리의 수리-역학적 거동에 관한 연구)

  • 천대성;이희석;이정인
    • Tunnel and Underground Space
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    • v.9 no.4
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    • pp.328-336
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    • 1999
  • To characterize the hydro-mechanical behavior of a rock joint, a rotary shear testing apparatus was devised in this study. Shear stress was driven by twisting the end of a sample in the rotary shear testing apparatus. The test results show that the rotary shear test underestimates the peak shear strength of a rock joint. The torque is known as a function of the radial distance from the axis of rotation, resulting in the radial variation of the shear stress. Fluid flow through rock joints is mainly dependent on the Joint roughness, contact area, initial aperture. To examine the dependency, the relationship between the hydraulic and the mechanical apertures for shear-flow was established by measuring the initial aperture. It shows that the mechanical aperture and the hydraulic aperture increase linearly with the dilatancy. The difference between the hydraulic and mechanical apertures describes the deviation from the behavior predicted by the parallel plate model.

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A Study on Mathematical Modeling of Forcing Function for the Piping Vibration of Petrochemical Plant Design (플랜트 설계 시 배관진동을 유발하는 가진 함수의 수학적 모델링)

  • 민선규;최명진
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.10a
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    • pp.591-595
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    • 1997
  • In analysis of piping vibration of petrochemical plant, the forcing functions mainly depend upon the equipment working mechanism and vibration resources in the piping systems. In general, harmonic function is used for the system with rotary equipments. Mechanical driving frequencies, wave functions, and response spectrum are used for reciprocating compressors, surge vibration of long transfer piping, and seismic/wind vibration, respectively. In this study, for the spray injection case inside the pipe, forcing function was modeled, in which two different fluids are distributed uniformly. To confirm the results, the scheme used for the forcing function was applied for real piping system. The vibration mode of the real system was consistent with the 4th mode obtained by simulation using the forcing function formulated in this study.

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Rotor Performance Optimization of the Canard Rotor Wing Aircraft (Canard Rotor Wing 항공기의 로터 성능 최적화 연구)

  • Jeon, Kwon-Su;Lee, Jae-Woo;Byun, Yung-Hwan;Yu, Yung H.
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.2
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    • pp.105-114
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    • 2008
  • In this study, the sizing and performance analysis program is developed for the canard rotor wing(CRW) aircraft which operates in dual modes (fixed wing mode and rotary wing mode). The developed program is verified for both fixed wing and rotary wing modes using the existing aircraft data and the design optimization formulation is made to perform the reconnaissance mission. For the canard rotor wing aircraft optimization , multi-objective function is constructed to consider both the fixed wing mode and rotary wing mode the weighting factor. For six design cases with different weighting factors and different design constraints, the optimization is performed and improved rotor design results are derived.

A Study on Deduction of Equivalent Circuit Parameters and Verification of Control Algorithm of Thrust Force of a Small-scaled LIM for a Railway Transit (철도차량용 선형유도전동기 축소형 모델의 등가회로 파라미터 도출 및 추진력 제어 알고리즘 검증 연구)

  • Park, Chan-Bae;Mok, Hyung-Soo;Lee, Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.59 no.7
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    • pp.1248-1254
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    • 2010
  • Authors conducted a deduction of some parameters using the magnetic equivalent circuit method and a verification study of the thrust force control algorithm of a rotary-typed small-scaled linear induction motor for a railway transit. In a LIM, it is possible to express the parameters of the magnetic equivalent circuit into a function of the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. It means that the LIM properties can be changed considerably by the shape of the secondary aluminium plate and the airgap between the LIM primary core and the secondary aluminium plate. So, authors analyzed a tendency of changes of the magnetic equivalent circuit parameters and the LIM characteristics by changing of the airgap of the secondary aluminium plate of a rotary-typed small-scaled LIM. And authors conducted a verification study of the indirect vector control algorithm with constant slip frequency by using the rotary-typed small-scaled LIM tester set on the basis of the calculated LIM parameters. Finally authors accomplished a research on applicability for LIM railway transit.

Development of Compact Phase-difference Controller for an Ultrasonic Rotary Motor (회전형 초음파모터의 소형 위상차 제어기 개발)

  • Yi Dong-Chang;Lee Myoung-Hoon;Lee Eu-Hark;Lee Sun-Pyo
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.8 s.185
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    • pp.64-71
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    • 2006
  • In this paper, a uniform speed controller for an ultrasonic rotary motor is developed using the phase-difference method. The phase difference method uses traveling waves to drive the ultrasonic motor. The traveling waves are obtained by adding two standing waves that have a different phase to each other. A compact phase-difference driver system is designed and integrated by combining VCO(Voltage Controlled Oscillator) and phase shifter. Theoretically the relationship between the phase difference in time and the rotational speed of the ultrasonic motor is sine function, which is verified by experiments. Then a series of experiments under various loading conditions are conducted to characterize the motor's performance that is the relationship between the speed and torque. Proportional-integral control is adopted for the uniform speed control. The proportional control unit calculates the compensating phase-difference using the rotating speed which is measured by an encoder and fed back. Integral control is used to eliminate steady-state errors. Differential control for reducing overshoot is not used since the response of ultrasonic motor is prompt due to its low inertia and friction-driving characteristics. The developed controller demonstrates reasonable performance overcoming disturbing torque and the changes in material properties due to continuous usage.