• Structural Engineering and Mechanics
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• v.64 no.1
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• pp.33-44
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• 2017

In this paper, the dynamic responses of train-bridge system under one-way and two-way high-speed train passing are studied. The 3D finite element modeling is used and the bridge and train are modeled considering their details. The created model is validated by the results of the dynamic field test. To study the effect of train speed, different train passing scenarios are analyzed, including one-way passing, two-way passing in different directions at same speeds, and two-way passing in different directions at different speeds. The results show that the locations of maximum acceleration are different in one-way and two-way passing modes, and the maximum values in two-way passing mode are higher than those in one-way passing mode, while the maximum accelerations in both modes are almost identical. The displacement and acceleration values in different scenarios show peaks at speeds of 260 and 120 km/h, due to the proximity of the natural frequencies of the bridge and loading frequencies of the train at these speeds.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.11
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• pp.1051-1058
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• 2012

The unified lateral control algorithm for automatic valet parking for various types of vehicles is presented and its feasibility is shown experimentally via field tests for the given parking scenario. First, a trajectory generation algorithm for forward driving and backward multi-step parking maneuvers is developed. Then, with consideration of different types of vehicles and operating conditions, a kinematic vehicle model is used and validated using field test data. Using the nonlinear vehicle model, the lateral controller is designed based on dynamic surface control. Finally the proposed lateral control law is validated via hardware-in-the-loop simulations for different types of vehicles and experimentally using a test vehicle through field tests.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.95-109
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• 2020

In this study, a total of six site cases were reviewed to assess the site applicability of portable dynamic cone penetration test (DCPT) by identifying the cause of damage to the damaged reinforced earth wall using portable dynamic cone penetration test. An improved dynamic concrete penetration tester was used at the site to enable ground surveys of more than 6 meters. The test results were compared with the results of the standard penetration test (SPT) and the correlation was analyzed. Through the analysis of various field application cases, it was found that portable dynamic cone penetration test was very convenient to apply at the site of the damaged reinforced earth wall, and DCPT could play a major role in identifying the cause of damage and verifying stability of the retaining wall by continuously identifying the ground strength. In addition, it was found that the results of the dynamic cone penetration test and the standard penetration test showed a correlation of N≒(1/3~2/3)·Nd in sandy soil.

• Proceedings of the Korean Geotechical Society Conference
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• 2004.03b
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• pp.910-921
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• 2004

In this study, the pilot tests on the reclaimed land were performed in order to find the suitable construction method with dynamic compaction Type I, Type II at different dynamic energy and hydraulic hammer compaction. The estimation of the compaction through the various pilot tests was performed by the CPT-qc, SPT-N and field density tests. As the result of the pilot tests, it shows that the dynamic compaction method is better than the hydraulic hammer compaction method in the effect of the ground improvement, especially dynamic compaction Type I is much superior to others. When it comes to method for measuring the intensity of the ground, the value of the cone penetration test-resistance(qc) is much suitable for the ground. Besides, the standards for the compaction control, which showed that over 10Mpa at 0 through 5meters in the upper layer and 7Mpa at 5 through 8meters in the lower layer in the CPT-qc, could be found without discrimination of the upper road and lower road on the reclaimed land. And it also found that the intensity of the reclaimed land gets back to the original status in about 10 through 15 days.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.656-665
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• 2010

Shear modulus has been recognized as one of the important soil properties in dynamic analysis of ground and can be calculated from in situ measurement of shear wave velocity. Field seismic tests are the most accurate but expensive methods to investigate dynamic ground characteristics. Due to that reason, empirical equations for estimating the shear wave velocity are widely used rather than conducting in-situ tests. The most common equations are based on the N value obtained in conjuctions with a standard penetration test. In this paper, the field datas of standard penetration test and suspension PS logging measured in 126 sites of Korea were summarized and the correlation equations between N value and shear wave velocity are suggested.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.626-628
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• 2000

This paper treats the dynamic analysis and test results of Linear Induction Motor. The dynamic analysis is performed by the d,q axis equivalent-circuit model. Equivalent-circut parameters are obtained with no-load, lock test and field analysis. As a results, simulation results are compared with that of dynamic test.

• Proceedings of the KSR Conference
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• 2003.10a
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• pp.156-161
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• 2003

Korean High Speed Train (KHST) has been tested on high speed line in JungBu site since it was developed in 2002. The data acquisition system was used to test successfully the on-line test for proving the dynamic performance of KHST. The recognition of system vibration mode for railway vehicle is essential to understand the characteristics of design for dynamic system and diagnose the dynamic problems of vehicle system during test and operation. But, up to now, there are the efforts to know the system vibration mode within limit of theoretical field only, not experimental approach with systematic method. The theoretical results are too reliable to apply to real design problem, because it is theoretically based on the homogeneous linear system although the real system have the nonlinear characteristics and vary the environmental conditions. Therefor, in this paper, it is proposed the efficient method of vibration analysis for rail vehicle system and this method apply to KHST to recognize the vibration mode characteristics of it. The results show that this method is able to make the system vibration modes for KHST clear.

• Smart Structures and Systems
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• v.11 no.2
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• pp.135-161
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• 2013

This work presents a test platform for the assessment and benchmarking of modern actuators which have been specifically developed for the new field and service robotics applications. This versatile platform has been designed for the comparative analysis of actuators of dissimilar technology and operating conditions. It combines a modular design to adapt to linear and rotational actuators of different sizes, shapes and functions, as well as those with different load capacities, power and displacement. This test platform emulates the kinematics of robotic joints while an adaptive antagonist-load actuator allows reproducing the variable dynamic loads that actuators used in real robotics applications will be subjected to. A data acquisition system is used for monitoring and analyzing test actuator performance. The test platform combines hardware and software in the loop to allow actuator performance characterization. The use of the proposed test platform is demonstrated through the characterization and benchmarking of three controllable impedance actuators recently being incorporated into modern robotics.

• Wind and Structures
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• v.13 no.6
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• pp.557-580
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• 2010

A new inflow turbulence generation method and a combined dynamic SGS model recently developed by the authors were applied to evaluate the wind effects on 508 m high Taipei 101 Tower. Unlike the majority of the past studies on large eddy simulation (LES) of wind effects on tall buildings, the present numerical simulations were conducted for the full-scale tall building with Reynolds number greater than $10^8$. The inflow turbulent flow field was generated based on the new method called discretizing and synthesizing of random flow generation technique (DSRFG) with a prominent feature that the generated wind velocity fluctuations satisfy any target spectrum and target profiles of turbulence intensity and turbulence integral length scale. The new dynamic SGS model takes both advantages of one-equation SGS model and a dynamic production term without test-filtering operation, which is particular suitable to relative coarse grid situations and high Reynolds number flows. The results of comparative investigations with and without generation of inflow turbulence show that: (1) proper simulation of an inflow turbulent field is essential in accurate evaluation of dynamic wind loads on a tall building and the prescribed inflow turbulence characteristics can be adequately imposed on the inflow boundary by the DSRFG method; (2) the DSRFG can generate a large number of random vortex-like patterns in oncoming flow, leading to good agreements of both mean and dynamic forces with wind tunnel test results; (3) The dynamic mechanism of the adopted SGS model behaves adequately in the present LES and its integration with the DSRFG technique can provide satisfactory predictions of the wind effects on the super-tall building.

• Proceedings of the KSR Conference
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• 2003.10b
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• pp.563-568
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• 2003

High-speed railway bridges subject to effect of dynamic loads by interaction between vehicle load which run specially fast and behavior of bridges. Such dynamic load effects result in fluctuations and fatigues to each elements as well as whole conduct of bridges. and is influenced in life of bridges. For these reason. Analysis and estimation of data about dynamic behavior of bridges occupies important factor in that estimate the remaining life of bridges and select the maintenance. repair and retrofit. In this paper. Analysis for the dynamic behavior of bridges using displacement and acceleration data that is actuality measure data to the bridges of Seoul-Susan high speed railroad test section has been made.