• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.41-49
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• 2001

최근의 대형 디젤 엔진은 고성능, 고효율 및 제작비용 절감 등의 요구에 따른 경량화, 유연화 추세로 설계되고 있는 한편, 엔진 자체에서 발생하는 고유의 큰 기전력 (가스폭발력, 왕복동 관성력, 각종 우력) 때문에 항상 진동 문제에 노출되어 있다. (중략)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.7 no.3
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• pp.101-109
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• 1987

The governing differential equations for the free vibration of general arch are derived including the effect of rotary inertia in addition to the usual actions. These differential equations are applied to the sinusoidal arch and the numerical methods are developed to analyze these equations. A trial eigenvalue method and the Runge-Kutta method are used to determine the natural frequencies and to perform the integration of the differential equations, respectively. A detailed studies are made of the lowest three vibration frequencies for hinged arches with the span length equal to 10 m. The effect of the rotary inertia is analyzed. And as the numerical results the frequency versus the rise of arch and the radius of gyration are presented in figures.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.14 no.4
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• pp.287-294
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• 2004

Dynamic Load/unload (L/UL) mechanism is an alternative to the contact start stop (CSS) technology which eliminates striction and wear failure modes associated with CSS. Inertia latch mechanism becomes important for mobile disk drives because of non operating shock performance. Various types of latch designs have been introduced in hard disk drives to limit a rotary actuator from sudden uncontrolled motion. In this paper, a single spring inertia latch is introduced for a small form optical disk drive, which uses a rotary actuator for moving an optical pick-up. A new small inertia latch with sin91e spring is designed to ensure both feasible and small size. The shock performance of the new inertia latch is experimentally verified.

• Journal of the Korean Institute of Telematics and Electronics T
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• v.35T no.3
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• pp.76-86
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• 1998

The Two-Mass Spring(TMS or Two-Inertia Resonance) system is one of the simplest models which generate a torsional vibration. In this system, it is required to design a controller achieving the control performance while suppressing the torsional vibration. In this paper, we compared and considered with the state feedback effects for the TMS system. By connecting each controller design to the state feedback control, we could predict each controller performances and decide weighting functions and parameters of LQ and $H_\infty$ controller.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.586-590
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• 2006

This paper presents a new vibration control device by which the mass and damping of a structure is increased equivalently. The vibration control system, named toggle-rotational inertia-viscous damper, can be utilized effectively in applications of small structural drift. Numerical analysis shows that because the relative drift of a structure can be effectively amplified by the toggle system, the device has a great performance in the vibration control without the increase of the damper capacity and size. It is also observed that vibration control effects is caused by the increase of equivalent mass and damping due to the rotational inertia and damping of the device.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.10
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• pp.1580-1588
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• 1997

A modeling method for the flapwise bending vibration of a rotating cantilever beam which has small slenderness ratio is presented in this paper. It is shown that as the slenderness ratio decreases the shear and rotary inertia effects increase. Such effects become critical for the accurate estimation of the natural frequencies and modeshapes, especially higher frequencies and modes, as the angular speed increases. It is also shown that the flapwise bending natural frequencies are higher than the chordwise bending natural frequencies. The discrepancy between first natural frequencies are especially significant when the hub radius ratio is small.

• Journal of KSNVE
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• v.6 no.2
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• pp.179-185
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• 1996

This paper presents a modeling method for the vibration analysis of a rotating beam the slenderness ratio of which is relatively small. The smaller the slenderness ratio becomes, the larger the shear and rotary inertia effects become. Such effects become critical for the accurate estimation of the natural frequencies and modeshapes, especially higher frequencies and modes, as the angular speed increases. It is also shown that the effects are important for the accurate estimation of the critical angular speed of the beam.

• Journal of the Korean Geotechnical Society
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• v.38 no.6
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• pp.17-28
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• 2022

The effect of the soil-structure interaction (SSI) on has been recently evaluated in shaking table tests. However, most of these tests were conducted on single-degree-of-freedom (SDOF) superstructures and a single-pile. This study investigates the inertial interaction effect of a multi-degree-of-freedom (MDOF) superstructure system with a group piles on a large-scale shaking table test. Whereas the SDOF superstructure system shows a single-frequency amplification tendency, the MDOF superstructure system exhibited amplification tendencies of the acceleration phase and frequency responses for multiple frequencies. In addition, the amplification phenomenon between the footing and the column-type superstructure exceeded that between the footing and the wall-type superstructure, indicating a greater inertial interaction effect of the column-type superstructure. The relationship between shear force and inertial force, the relative vertical and horizontal displacements on the footing was figured out. Also, the ananlysis of dynamic p-y curve at each depth was conducted. In summary, the MDOF and SDOP superstructure systems exhibited different behaviors and the column-type superstructure exerted a higher interaction effect than the wall-type superstructure.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.4
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• pp.308-315
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• 2016

A new technique for Attitude & Heading Reference System (AHRS) by using sequential measurement noise covariance (SMNC) is addressed in a vibration environments in this paper. In particular, a low-cost inertial measurement unit in general diverges in the acceleration phase or vibrating environments due to inherent properties of gravity and acceleration. In this paper, by considering current and prior measurements to estimate actual attitudes and headings in a local frame, the proposed technique overcomes these problems efficiently. Finally, the performance of the suggested approach is verified by numerical simulations.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.2536-2539
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• 2008

A study has been made on how to occur inertial oscillations in a rotating flow. The flow is considered to be induced by differentially-rotating top and bottom disks with infinite radius. The top and bottom disks are assumed to be set in motion over a finite initial start-up time duration from initial solid body rotation ($\Omega$) to each finial state, i.e., the top disk is rotating at the angular velocity (${\Omega}+{\Delta}{\Omega}$) and the bottom disk (${\Omega}-{\Delta}{\Omega}$). The system Reynolds number, which is a reciprocal of conventional Ekman number in rotating flows, is very high so that a boundary layer flow near disks is pronounced. From a strict theoretical analysis, it is clearly found the fact that inertial oscillation in a rotating flow is caused by excessive input of torque during start-up phase. Above finding comes from the following physics of theoretical result: in the case of abrupt start-up within very shorter time-duration than spin-up time scale, the inertial oscillation is magnified but it could be completely depressed in the case of mildly accelerated start-up, i.e., start-up process being established over diffusion time scale.