• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.250-254
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• 2002

It is conducted to analyze vibration loads on KSR-III(KSR: Korea Sounding Rocket) and its major segments during their ground transportation and various handling process. These loads may be different from the real flight environment. Inadequate assessment of these loads can cause not only local damages on the rocket system but also the critical problem like flight mission failure. Therefore, transportation and handling loads must be considered during design and attenuated to ensure that the rocket structural damage does not occur. This work is concerned with the generation of criteria and prediction of transportation and handling loads for KSR-III. The results show that the shipping container is well designed to satisfy the design requirements. The maximum vibration level recorded during whole transportation and handling for KSR-III is less than 2g, the criteria of KSR-III movement condition.

• Journal of Biosystems Engineering
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• v.37 no.6
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• pp.359-364
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• 2012

Purpose: This study was conducted to analyze the vibration absorption effect for the agricultural product transportation-trailer equipped with vibration absorbable connecting hitch, leaf spring suspension, and shock absorber simultaneously (HLS), comparing with the trailer equipped with vibration absorbable connecting hitch only(H), trailer equipped with connecting hitch and leaf spring suspension (HL), and existing trailer with no vibration absorption device (E). Methods: Vertical accelerations were measured at driver seat and front, middle, rear parts of trailer bottom with no load for 4 types of transportation-trailer, and analyzed using FFT analyzer. Results: The magnitude of average vibration accelerations occurred up to 20 Hz, at this low frequencies the severe damage for agricultural products could be represented, was lower (maximum 6 times) for HLS trailer compared with H trailer. And vibration absorption effect for HLS trailer was also higher up to 40-80 Hz and 80-100 Hz, but the difference was less. At driver seat, the vibration absorption effect was high severely for HL and HLS trailer, and the magnitude of vibration acceleration was showed less difference in comparing at trailer bottom. Conclusions: From the test results, it could be recommended that the agricultural products transportation trailer should be equipped with vibration absorption device of HLS.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.19 no.10
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• pp.1083-1091
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• 2009

Modern military equipments are tend to be mounted on a movable truck for their survivability and operation performance. Special units and electronic equipments installed on the truck experience the vibration caused by road roughness during their transport. The level of the transportation vibration is affected by both road conditions and vehicle speeds. In this paper, various experiments on the vibration characteristics of the equipment are carried out via road tests. Transportation vibration is also investigated by numerical analysis using FEM, and natural frequencies and random responses of the launcher are obtained. The PSD and RMS values of acceleration of the equipment are predicted and compared with test results.

• Journal of the Korean Geosynthetics Society
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• v.21 no.4
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• pp.41-53
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• 2022

In the excavation work like blasting/excavator work bordering on the urban railway, the dynamic safety of railway structures like tunnel, open-cut box structure and elevated bridge was investigated by numerical analysis in this study. The practically presented criteria on influential zones at the blasting work in the construction industry was numerically checked in cases of the precise vibration-controlled blasting (type II) and the small scale vibration-controlled blasting (type III) and it was shown that the criteria on blasting work methods needed to be supplemented through continuous field tests and numerical analyses. The influence of excavation vibration by mechanical excavators was especially investigated in case of earth auger and breaker. The numerical analysis of tunnel shows that the criteria on vibration velocities from the regression analysis of field test values was conservative. The amplification phenomenon of excavating vibration velocity was shown passing through the backfilling soil between the earth auger and the open-cut box structure. It was shown that the added-vibration on the superstructure of elevated bridge was occurred at the bottom of pile like earthquake when the excavator vibration was arriving at the pile toe. The systematic and continuous research on the vibration effect from excavating works was needed for the safety of urban railway structures and nearby facilities.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.53-59
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• 2019

To reduce the vibrations and shocks during the cargo transportation of high value-added goods, the vibration history was measured on the truck transportation section (Asan-Uiwang) and the freight train transportation section (Uiwang-Pusan). The internal vibrations of the container were obtained by attaching acceleration sensors in three axis directions (longitudinal, lateral. and vertical directions) on the front and rear bogies. The rail vibration profile (0.29Grms) proposed in ASTM D-4169 was approximately 50% higher than the truck vibration profile (0.54Grms). The overall vibration was 16% and 33 % lower in the longitudinal and transverse directions, respectively, compared to the ASTM truck transport vibration profile. On the other hand, the vertical vibration measurement history partially exceeded the ASTM truck transport vibration profile over the range, 4 - 15Hz, and over 60Hz. The vibration measurement history of the cargo train was similar to that of the road. The longitudinal and lateral vibration history was lower than the ASTM D-4169 rail vibration profile, while the vertical history was over 30Hz.

• Smart Structures and Systems
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• v.17 no.2
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• pp.257-274
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• 2016

The nonlocal static bending, buckling, free and forced vibrations of graphene nanosheets are examined based on the Kirchhoff plate theory and Taylor expansion approach. The nonlocal nanoplate model incorporates the length scale parameter which can capture the small scale effect. The governing equations are derived using Hamilton's principle and the Navier-type solution is developed for simply-supported graphene nanosheets. The analytical results are proposed for deflection, natural frequency, amplitude of forced vibration and buckling load. Moreover, the effects of nonlocal parameter, half wave number and three-dimensional sizes on the static, dynamic and stability responses of the graphene nanosheets are discussed. Some illustrative examples are also addressed to verify the present model, methodology and solution. The results show that the new nanoplate model produces larger deflection, smaller circular frequencies, amplitude and buckling load compared with the classical model.

• Journal of Biosystems Engineering
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• v.27 no.5
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• pp.391-398
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• 2002

During handling unitized products, they are subjected to a variety of environmental hazards. Shock and vibration hazards are generally considered the most damaging of the environmental hazards on a product and it may encounter while passing through the distribution environment. A major cause of shock damage to products is drops during manual handling. The increasing use of unitization of pallets has been resulted in a reduction of the shock hazards. This has caused an increasing interest in research focused on vibration caused dam age. Damage to the product by the vibration most often occurs when a product or a product component has a natural frequency that falls within the range of the forcing frequencies of the particular mode of transportation being used. Transportation vibration is also a major cause of fruit and vegetable quality loss due to mechanical damage. This study was conducted to determine the vibration characteristics of the corrugated fiberboard bones for packages of pears, and to investigate the degree of vibration injury of the pears in the boxes during the simulated transportation environment. The vibration tests were performed on an electrohydraulic vibration exciter. The input acceleration to exciter was fixed at 0.25 G for a single container resonance test and 0.5 G for the vertical stacked container over the frequency range from 3 to 100 Hz. Function generator (HP-33120A) was connected by wire to the vibration exciter for controlling the input acceleration at a continuous logarithmic sweep rate of 1.0 octave per min. The peak frequency and acceleration on the single box test were 22.02 Hz, 1.5425 G respectively, and these values on the vertical stacked boxes were observed from the bottom box 19.02, 18.14, 16.62 and 15.40 Hz and 2.2987, 3.7654. 5.6087, and 7.9582 G, respectively. The pear in the bottom box had a slightly higher damage level than the fruit packed in the other stacked boxes. It is desirable that the package and transportation system has to be so designed that 15∼20 Hz frequency will not occur during the transportation environment.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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• pp.330.2-330
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• 2002

It is conducted to analyze vibration loads on KSR-III and its major segments during their ground transportation and various handling process. These loads may be different from the real flight environment. Inadequate assessment of these loads can cause not only local damages on the rocket system but also the critical problem like flight mission failure. Therefore, transportation and handling loads must be considered during design and attenuated to ensure that the rocket structural damage does not occur. (omitted)

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.11 no.1
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• pp.11-16
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• 2005

Fruits are subjected to complex dynamic stresses in the transportation environment. During a long journey form the production area to markets, there is always some degree of vibration present. Vibration inputs are transmitted from the vehicle through the packaging to the fruit. Inside, these cause sustained bouncing of fruits against each other and container wall. These steady state vibration input may cause serious fruit injury, and this damage is particularly severe whenever the fruit inside the package is free to bounce, and is vibrated at its resonance frequency. The determination of the resonant frequencies of the fruit may help the packaging designer to determine the proper packaging system providing adequate protection for the fruit, and to understand the complex interaction between the components of fruit when they relate to expected transportation vibration inputs. The first frequency of the pear in packaged freight be stacked in resonance frequency band of the pear packaged freight was increased from the bottom to the top of the stack but the second frequency of that in resonance frequency band of the pear was decreased. This indicated that the high damage score of the pear in bottom tier in vibration test was due to higher acceleration level in resonance frequency band of the pear.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.1
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• pp.29-35
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• 2019

The unit modular system is a type of prefabricated construction method that completes the building by uniting the modular units on site by transporting the unit module structure manufactured in the factory to the site. Since the unit module structure is not only the frame but also the finished form including the inner and outer materials, it is most likely to be brought into the field. Therefore, not only the damage of the inner and outer materials but also deformation of frame structure due to the vibration generated during the transportation of the vehicle, And it is necessary to take appropriate methods when transporting the module structure. However, there are no methods to prevent modular structure damage due to vehicle vibration in domestic and foreign modular transportation guidelines or standards. In this study, we investigate the vibrations during the vehicle transportation of the module structure through the road driving test, identify the vibration frequency characteristics of the vehicle through FFT analysis, and propose a vibration reduction methods for module transportation.