• Journal of KSNVE
• /
• v.9 no.1
• /
• pp.25-32
• /
• 1999

Ground vibrations induced from road were investigated to get the basic data that can be used to prepare countermeasures for environmental vibration problems. Vibration levels were measured simultaneously at three points in double distances from road. These data were analyzed with the type of vehicles. roads, media to understand the magnitudes and characteristics of distance attenuation of road vibrations. Vibration levels recorded on tapes were analyzed to understand the characteristics of frequency of road vibration. The range which could be influenced by the road vibration was estimated to take into account the mean of$L_{max}$ and distance attenuation of vibration level 5 m from roadside.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.12 no.3
• /
• pp.266-271
• /
• 2009

Electronic equipments and a missile carried by heavy trucks are often subjected to vibration and shock excitation during their transportation. Electronic equipments are so vulnerable to vibration and shock input that it is necessary to know in advance the vibration level of the truck which cause the damage of equipments. Road tests of a heavy truck carrying a canister on different road conditions such as paved road, unpaved road, and washboard are performed and the effect of road conditions on the vibration characteristics are analyzed. Vibration levels were measured at various locations of the truck along the path through which vibration was transmitted. This study reveals that the velocity of the truck as well as the road surface conditions are main factors which affect the vibration levels of the truck. The power spectrum density of the measured vibration signal and the factors affecting the PSD are also analyzed in this paper.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.16 no.6
• /
• pp.1211-1216
• /
• 2002

To evaluate whole-body vibration(WBV) exposure and fatigue-decreased proficiency(FDP) boundary in passenger car driver, several roads in Busan were divided into 3 types by the condition of road surface; Road 1 was partially damaged, Road 2 was normal without damage, and Road 3 was better than Road 2. The results were following: The highest passenger driver's exposures to whole-body vibration acceleration and fatigue-decreased proficiency boundary at 40km/h were 0.108m/s² and about 2099 minutes in Road 2 for xh axis, 0.134m/s² and about 1585 minutes in Road 2 for yh axis, and 0.183m/s² and about 1053 minutes in Road 2 for zh axis, respectively. The highest passenger driver's exposures to whole-body vibration acceleration and fatigue-decreased proficiency boundary at 80km/h were 0.219m/s² and about 830 minutes in Road 3 xh axis, 0.203m/s² and about 918 minutes in Road 3 for yh axis, and 0.622m/s² and about 195 minutes in Road 1 for zh axis, respectively. The highest vector sums of whole-body vibration exposure at 40km/h and 804km/h were 0.328m/s² in Road 2 and 0.730m/s² in Road 1, respectively. The highest crest factors at 40km/h were 4.25 in Road 1 for xh, 4.51 in Road 3 for yh, and 5.81 in Road 2 for zh, respectively. The highest crest factors at 80km/h were 5.57 in Road 1 for xh, 5.60 in Road 2 for yh, and 6.46 in Road 3 for zh, respectively. The highest transmissibilities of whole-body vibration from floor to seat at 40km/h and 80km/h were 0.89 in Road 3 and 0.82 in Road 3 for xh axis, 0.83 in Road 3 and 0.87 in Road 1 and 2 for yh, and 0.80 in Road 2 and 0.92 in Road 1 tor zh axis, respectively. The highest fatigue-decreased proficiency boundaries for whole-body vibration exposure of passenger car driver in floor and seat were 457 minutes in Road 3 and 583 minutes in Road 3 at 40km/h and 159 minutes in Road 2 and 251 minutes in Road 2 at 80km/h, respectively.

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

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.581-586
• /
• 2014

In general vibration test considers both harmonic vibration and random vibration, When developing the vehicle component. But the effect of harmonic vibration is larger in the parts around the vehicle engine, sole testing the harmonic vibration is considered. In this study, the fatigue damage of the linear system fixed around the engine is analyzed when the effect of random vibration is higher, harsher than the normal road surface condition. In condition the vehicle speed and the engine RPM are similar, the higher the harshness of the road surface condition is, the larger the fatigue damage level is. Therefore both random vibration and harmonic vibration must be considered in vibration test of components around the engine. Proposing the sine on random(SOR) vibration test that can exam considering both of vibrations, harmonic and random.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.821-822
• /
• 2014

When performing the tunnel excavation blasting, the lower road structure can cause the damage of the structure caused by blasting vibration. In this case the existing structurel meet all of the static and the dynamic stability. But in the domestic management of building structures is presented vibration and is the only criteria, and the criteria for major civil engineering structures insufficient research situation. This study examined the influence of the road structure according to the blast vibration by utilizing the numerical analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2003.11a
• /
• pp.760-765
• /
• 2003

This study is performed in order to determine a method to solve vibration-borne problems by isolating the vibration that is generated by vehicles in case a road passes through a building and also to verify its applicability and effect both theoretically and experimentally.

• Structural Engineering and Mechanics
• /
• v.51 no.2
• /
• pp.315-331
• /
• 2014

The present study investigated the effect of the correlation of the measured road roughness profiles corresponding to the left and right wheels of a vehicle on the vibration of a vehicle-bridge coupling system. Four sets of road roughness profiles were measured by a laser road-testing vehicle. A correlation analysis was carried out on the four roughness samples, and two samples with the strongest correlation and weakest correlation were selected for the power spectral density, autocorrelation and cross-correlation analyses. The scenario of a three-axle truck moving across a rigid-frame arch bridge was used as an example. The two selected road roughness profiles were used as inputs to the vehicle-bridge coupling system. Three different input modes were adopted in the numerical analysis: (1) using the measured road roughness profile of the left wheel for the input of both wheels in the numerical simulation; (2) using the measured road roughness profile of the right wheel for both wheels; and (3) using the measured road roughness profiles corresponding to left and right wheels for the input corresponding to the vehicle's left and right wheels, respectively. The influence of the three input modes on the vibration of the vehicle-bridge system was analyzed and compared in detail. The results show that the correlation of the road roughness profiles corresponding to left and right wheels and the selected roughness input mode both have a significant influence on the vibration of the vehicle-bridge coupling system.

• International Journal of Highway Engineering
• /
• v.15 no.3
• /
• pp.23-29
• /
• 2013

PURPOSES: This paper aims to give a guideline and the way to apply the advanced composite materials theory to the road structures with different cross sections to the practicing engineers. METHODS: To simple but exact method of calculating natural frequencies corresponding to the modes of vibration of road structures with different cross sections and arbitrary boundary conditions. The effect of the $D_{22}$ stiffness on the natural frequency is rigorously investigated. RESULTS: Simple method of vibration analysis for calculating the natural frequency of the different cross sections is presented. CONCLUSIONS: Simple method of vibration analysis for calculating the natural frequency of the different cross sections is presented. This method is a simple but exact method of calculating natural frequencies of the road structures with different cross sections. This method is extended to be applied to two dimensional problems including composite laminated road structures.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2014.10a
• /
• pp.262-266
• /
• 2014

Military vehicle equipped with an antenna and a shelter for operating radar has a vibration exposure during driving time. This vibration would have influence on structure of military vehicle critically. In this paper, driving stability of the military vehicle is obtained through the vibration response analysis. And, vibration level of the military vehicle satisfied the military vibration specification through analysis and comparing the MIL-STD-810G. PSD and Grms data obtained by road test can be used for vibration test specification of cabinets and electronic equipment in shelter.