• Structural Engineering and Mechanics
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• 제65권3호
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• pp.349-357
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• 2018

An extensive research was undertaken to study the vibration serviceability of a long-span and light-weight floor subjected to human loading experimentally and numerically. Specifically, heel-drop test was first conducted to capture the floor's natural frequencies and damping ratios, followed by jumping and running tests to obtain the acceleration responses. In addition, numerical simulations considering walking excitation were performed to further evaluate the vibration performance of a multi-panel floor under different loading cases and walking rates. The floor is found to have a high frequency (11.67 Hz) and a low damping ratio (2.32%). The comparison of the test results with the published data from the 1997 AISC Design Guide 11 indicates that the floor exhibits satisfactory vibration perceptibility overall. The study results show that the peak acceleration is affected by the walking path, walking rate, and adjacent structure. A simpler loading case may be considered in design in place of a more complex one.

• Smart Structures and Systems
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• 제23권5호
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• pp.467-478
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• 2019

Composite floor structures formed by continuous slab panels may be susceptible to excessive vibrations, even when properly designed in terms of ultimate limit state criteria. This is due to the inherent vibration characteristics of continuous floor slabs composed by precast orthotropic reinforced concrete panels supported by steel beams. These floor structures display close spaced multimode vibration frequencies and this dynamic characteristic results in a non-trivial vibration problem. Structural stiffening and/or insertion of struts between floors are the usual tentative solution applied to existing vibrating floor structures. Such structural alterations are in general expensive and unsuitable. In this paper, this vibration problem is analyzed on the basis of results obtained from experimental measurements in typical composite floors and their theoretical counterpart obtained with computational modeling simulations. A passive control system composed by multiple synchronized dynamic attenuators (MSDA) was designed and installed in these floor structures and its efficiency was evaluated both experimentally and through numerical simulations. The results obtained from experimental tests of the continuous slab panels under human walking dynamic action proved the effectiveness of this control system in reducing vibrations amplitudes.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.446-452
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• 2002

This paper Presents a 3-D design and a Vibration control of a new walking R.G.O.(Robotic Gait Orthosis) and would like to develop a simulation by this walking system. The vibration control and evaluation of the new knee joint mechanism on the biped walking R.G.O.(Robotic Gait Orthosis) was a very unique system and was to obtain by the 3-axis accelerometer with a low frequency vibration for the paraplegia It will be expect that the spinal cord injury patients are able to recover effectively by a biped walking R.G.O.. The new knee joint system of both legs were adopted with a good kinematic characteristics. It was designed attached a DC-srevo motor and controller, with a human wear type. It was able to accomodate itself to a environments of S.C.I. Patients. It will be expect that the spinal cord injury patients are able to recover effectively by a new walking R.G.O. system.

• 대한의용생체공학회:의공학회지
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• 제30권2호
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• pp.162-168
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• 2009

Implantable middle ear hearing devices (IMEHDs) have been widely studied as an alternative hearing aids to solve the problems of conventional hearing aids. Vibration transducer of middle ear hearing aids is a key component because vibration characteristics of transducer is directly involved performance of hearing aids. So, the study about middle ear hearing aids concentrate on the transducers. A floating mass type transducer is most efficient. In this paper, we suggest a lumped mechanical model of electromagnetic floating mass transducer implanted on human middle ear. The proposed model enables analysis of the vibration characteristics of a floating mass transducer and prediction of the variation after implant on ossicle that offers a simple and easy to analyze. The parameters was drawn based on the components and the structures of transducer. The Lumped mechanical model was converted by the electrical-mechanical equivalent model, and simulated using PSpice. So, we investigated vibration characteristics of transducer influenced it's components. And we predict vibration characteristics of stapes footplate due to implanted transducer's vibration using combining model of transducer and human ear. To prove the feasibility of the suggested model, we fabricated a differential floating mass transducer (DFMT) as one of floating mass transducers and performed experiments using the human temporal bones.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.1425-1429
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• 2007

Consumer's product selection measures are being shifted from the units' operational performance to overall performance. Low noise, low vibration, and low power consumption rate, etc. which used to be additional quality indices, now become vital performance factors. Especially, noise and vibration characteristics are being considered as equivalent to/or even more critical than operational performance in certain products such as office machines and home entertainment systems, which share the same space with human being's daily life. Therefore, noise reduction and sound quality improvement technology becomes an inevitable design issue for those applications. Qualitative noise characteristics of rotating polygonal disk applied to digital printer systems are presented. Overall sound pressure level change and tonal noise variation with respect to the geometrical properties of polygonal disk, operational speed, and others are briefly discussed based on experimental results.

• 한국소음진동공학회논문집
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• 제18권6호
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• pp.606-611
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• 2008

Consumer's product selection measures are being shifted from the units' operational performance to overall performance. Low noise, low vibration, and low power consumption rate, etc. which used to be additional quality indices, now become vital performance factors. Especially, noise and vibration characteristics are being considered as equivalent to/or even more critical than operational performance in certain products such as office machines and home entertainment systems, which share the same space with human being's daily life. Therefore, noise reduction and sound quality improvement technology becomes an inevitable design issue for those applications. Qualitative noise characteristics of rotating polygonal disk applied to digital printer systems are presented. Overall sound pressure level change and tonal noise variation with respect to the geometrical properties of polygonal disk, operational speed, and others are briefly discussed based on experimental results.

• 전자공학회지
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• 제28권6호
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• pp.91.1-91
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• 2001

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.356-361
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• 2001

A research to maximize the force transmitted from a vibration motor at the vibration mode, installed in the cellular phone jig, is presented in this study. When the natural frequencies corresponding to the structural vibration modes of the set exist within the range of the driving frequencies acquired by changing the RPM of the vibration motor, the structural vibration resonance is applicable to maximization of the vibration force sensible to the human body such as hands, arms, and hips. The analytical modal analysis using the Finite Elements and the experimental modal testing for the set jig were performed in order to understand the structural modes and the corresponding frequencies. Then the dynamic responses of the set jig to the given driving frequency were measured and the results on maximizing the vibration were confirmed by the FEM dynamic simulation.

• 한국소음진동공학회논문집
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• 제21권1호
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• pp.31-40
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• 2011

This paper examines the dynamic characteristics of a human carpal muscle through theoretical analysis and experiment. The carpal muscle was modeled as a 1-DOF vibration system and vibration response due to a ramp function force was calculated. The electromyogram signal corresponding to the muscle excitation force was measured, and the excitation force function of an envelope curve from the electromyogram signal was extracted. The ramp input function of electrical stimulation to the carpal muscle was applied by using a device for functional electrical stimulation, and the angular displacements corresponding to steady state response were measured. Theoretical calculations of the vibration response displacements were compared with the experimental results of the angular displacements, and have shown a good agreement with the result that is linearly proportional to the excitation force magnitude. As a result, the relationship between the input current of the electrical stimulation and the excitation force magnitude was inferred. The result was shown that it can be applied to develop rehabilitation training devices.

• 소음진동
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• 제11권1호
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• pp.76-81
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• 2001

This paper addresses experimental results carried out to investigate the transmission of seat vibration to the head for Korean. Vertical seat vibration in the frequency range of 0.5-30 Hz was applied to a seated Korean male subject. To examine the intra-variable effects on transmissibility, five different postures and three different vibration excitation levels were considered. The applied acceleration and head accelerations of the seated subject were measured simultaneously by using a 6-axes bite-bar. Detailed experimental results of measured transmissibilities are illustrated for each posture and/or vibration excitation level, and they were compared to an International Standard. They are found to allow the identification of dynamic characteristics of Korean seated body for various reat vibration environments. Furthermore, they are expected to be very useful in designing new seats for automotive and railway vehicles and in improving their vibration ride quality.