• Proceedings of the KSR Conference
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• 2002.10b
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• pp.892-897
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• 2002

The research was requested by Meridian Rail Corporation in United States. The Swing Motion Bogie can application by Korea style if synthesize study result of bogie strength evaluation, bogie dynamic characteristics analysis, actual test(maximum speed, derailment coefficient, lateral force, vertical force, vibration acceleration, steady state lateral acceleration) etc..

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.10a
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• pp.6-11
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• 2005

During the acceptance test of KTX, lateral vibration of carbody at the tail of the train was found. The carbody lateral vibration was occurred on a straight line in the winter season. We analysis to find the cause of the lateral vibration and the countermeasure. The analysis results show that lateral stiffness of air spring is the most important parameter to cause the carbody lateral vibration. The lateral vibration is occurred at frequency range $0.5{\sim}0.6Hz$ with a negative damping value. We also blow that natural frequency of lateral vibration increase with the train speed up to 1Hz at 300km/h.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.821-828
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• 2011

A significantly larger lateral load and moment are applied on a high speed railway bridge foundation than other bridge foundations. Therefore most of bridge foundations on Honam high speed railway project were designed by high strength steel pipe piles to resist lateral load and moment, which caused the increase of construction costs. In order to perform optimum design, it is important to estimate accurate lateral resistance when designing this type of structure. Lateral load tests were carried out based on the field design data with the purpose of examining the lateral behavioral characteristics of a railway bridge foundation. The standard load test method(ASTM D 3966) was used for field tests by applying twice of design load. Total four load tests were performed on high speed railway bridge foundations with strain gages installed by every 1m along piles to measure load-resistance characteristics under applied lateral loads. The back-calculated P-y curves from strain gages were compared with estimated P-y curves using theoretical methods based on geotechnical investment data. Back-calculated P-y curves from field tests for sand and clay ground conditions were presented in this paper, which are different from theoretical P-y curves. By using the research results of this study, more accurate estimations of pile design under lateral loads can be available for similar geotechnical conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.4
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• pp.848-852
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• 2007

Many numerical analysis tools for predicting penetration speed of sheet pile are thought to be unreliable because they overestimate penetration speed for shallow depth of penetration. In order to overcome the defects of numerical analysis, lateral vibration model of sheet pile was suggested and energy consumption due to lateral vibration of sheet pile was estimated. Also, load reduction factor which explains reduction of vibratory driving force due to lateral vibration was introduced.

• Journal of Sensor Science and Technology
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• v.30 no.1
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• pp.30-35
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• 2021

To operate an underwater robot in an environment with fluid flow, it is necessary to recognize the speed and direction of the fluid and implement motion control based on these characteristics. Fish have a lateral line that performs this function. In this study, to develop an artificial lateral line sensor that mimics a fish, we developed a method to measure the flow speed and the incident angle of the fluid using a pressure sensor. Several experiments were conducted, and based on the results, the tendency according to the change in the flow speed and the incident angle of the fluid was confirmed. It is believed that additional research can aid in the development of an artificial lateral line sensor.

• Structural Engineering and Mechanics
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• v.83 no.6
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• pp.835-851
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• 2022

This paper analyzes the variation law of the pipe lateral vibration characteristics, it was treated as a beam model, and was dispersed into several subunits based on the FEM. The corresponding stiffness and mass matrix of the pipe was deduced by using Hermite interpolation function, and the overall dynamic balance equation was established. The lateral vibration under different pipe lengths, thicknesses and towing speeds are solved by integral method. The results show that the pipe vibration trend decreases first and then increases, and the vibration value at the ore bin is larger than that at the pump set, and the value at the top is the largest, and the least value location can change with the length increase. Increasing length and thickness can reduce lateral vibration value, while increasing speed can increase the value. Neither the thickness nor the towing speed will change the location where the least value occurs. The vibration intensity will increase with the decrease of pipe length and thickness and the increase of towing speed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.797-803
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• 2019

This study was carried out to reduce the lateral vibration of high-speed electric multiple units. In the study, the high-speed electric multiple unit prototype (HEMU-430X) has a high lateral vibration at low equivalent conicity regardless of the wheel profiles (XP55, GV40, S1002). As wheel wear progresses and the equivalent conicity increases, the lateral vibration tends to decrease. The reason is that a combination of the suspension characteristics causes the body and bogie to resonate at a frequency of 1.4 Hz when the equivalent conicity is low, resulting in body hunting. An investigation of the lateral vibration of overseas high-speed trains showed that a decrease in the hydraulic stiffness of the yaw damper could improve the vibration. The series stiffness of the yaw damper is a combination of the hydraulic stiffness and elastic joint. In this study, an attempt was made to improve the lateral vibration by lowering the stiffness of the elastic joint. The series stiffness of the adjusted yaw damper was approximately 60% compared to the original one. The on track test results showed improvement in the lateral vibration for both running directions. The vibration reduction method of this study can be used for EMU-250 and EMU-320 in future commercial operations.

• Journal of Aerospace System Engineering
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• v.7 no.2
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• pp.23-28
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• 2013

This is a research on the method of how to improve lateral stability for the small general aviation airplane to meet the FAR part 23 requirements. This research is based on the experience of certification flight tests of KC-100 airplane for Korea first type certification. KAS/FAR Part 23.177 is the static lateral and directional stability requirement. And, 23.177(b) requires to show the tendency to raise the low wing in steady heading side slip maneuver. However, it is very difficult for the low wing to be raised at the low speed during the steady heading side slip maneuver. So, the requirement allows not be negative at the $1.2V_{S1}$ speed and takeoff configuration. (static stability requirement requires low wing picked up at any speed except $1.2V_{S1}$ speed and takeoff configuration) In this paper, the static lateral stability requirements and the lessons & learned of KC-100 airplane certification flight test results are shown.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.05a
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• pp.722-728
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• 2001

Applying a general coupled lateral and torsional vibration finite element model of gear pair element this paper intends to look into in detail the coupled lateral and torsional vibration characteristics in a turbo-chiller rotor bearing system, having a bull-pinion speed increasing gear. Investigations have been carried out systematically by comparing the uncoupled and coupled analyses natural vibration frequencies and their mode shapes upon varying the gear mesh stiffness, and also by comparing the strain energies of lateral and torsional vibration modes. Results have shown that some modes may have coupled lateral and torsional mode characteristics as the gear mesh stiffness increases over a certain value, and moreover that their associated dominant modes may be different from their initial modes, i.e., the dominant mode changes from an initial torsional one to a lateral one or from an initial lateral one to a torsional one.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1034-1039
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• 2000

In turbo-machines operated at high speeds through gear speed increasers a precise coupled analysis of lateral and torsional vibrations is required to achieve highly reliable designs with low vibration and low noise levels, where the vibration coupling is due to the gear pair mesh stiffness. In this paper, applying the generalized coupled lateral-torsional finite element model of a gear pair element, has been analyzed a coupled lateral-torsional vibration of the prototype 800 RT turbo-chiller rotor-bearing system with a bull-pinion gear speed increaser. Results have shown that the coupled torsional natural frequencies have decreased due to the coupling effect of lateral vibration and particularly, the 2nd torsional natural frequency and its mode shape have had big changes. However, changes of lateral vibration characteristics have been noticed only at high lateral whirl natural frequencies above 15,000 rpm.