• 한국산업융합학회 논문집
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• 제5권3호
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• pp.247-254
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• 2002

This study has researched the following conclusion to compare to the existing theory and to examine lateral earth pressure, which have measured to add incremental load on sandy soil, and were different in types of compaction by modeling earth pressure test. Lateral earth pressure by incremental load shows that it is increasing at depth forty four centimeters as 2/3H point for wall high, and under 2/3 H point the variation of earth pressure on incremental load is not conspicuous. Therefor, the more a position of surcharge load is close with fixed wall, the more a variation of lateral earth pressure marks considerably. According to relative compaction density of soil, lateral earth pressure turns up larger effective value for layer compaction test to a thickness of thirty three centimeters than layer compaction test to a thickness of twenty centimeters by the roller.

• Structural Monitoring and Maintenance
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• 제6권4호
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• pp.269-289
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• 2019

This study investigated experimentally the response of thick reinforced concrete specimens having hollow cores with critical parameters. The investigation includes testing of twelve specimens that are solid and hollow-core slab models. Each specimen consists of two pieces, the piece dimensions are (1.2 m) length, (0.3 m) width and (20 cm) thickness tested under both monotonic and repeated loading. The test program is carried out to study the effects of load type, core diameters, core shape, number of cores, and steel fiber existence. Load versus deflection at mid span, failure modes, and crack patterns were obtained during the test. The test results showed that core shape and core number has remarkable influenced on cracking pattern, ultimate load, and failure mode. Also, when considering repeated loading protocol, the ultimate load capacity, load at yielding, and ductility is reduced.

• Tribology and Lubricants
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• 제25권2호
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• pp.108-113
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• 2009

This paper presents a experimental results for the performance evaluation of a double-bumped air foil bearing. The test results of a double-bumped AFB is compared with a single-bumped AFB at a heavily-loaded condition. The diameter of the test bearing is 50 mm, and the axial length is 50 mm. Nominal clearance of the single-bumped AFB is evaluated as $105{\mu}m$, and that of the double-bumped AFB is as $95{\mu}m$. The test of the AFBs are demonstrated at 3 test mode; the load variation mode, the speed variation mode, and start-stop mode. The single-bumped AFB demonstrated a upward load-carrying capacity of 95 N and a downward load-carrying capacity of 130 N at 20,000 rpm. The double-bumped AFB demonstrated a upward load-carrying capacity of 170 N and a downward load-carrying capacity of 170 N at 20,000 rpm. The single-bumped AFB demonstrated a downward lift-off speed of 16,300 rpm at 105 N. The double-bumped AFB demonstrated a downward lift-off speed of 15,400 rpm at 105 N. The start-stop test of the AFBs assure 5,000 cycle endurance life. The test results are compared with the theoretical calculation results. The test and theorectical results show thata double-bump air foil bearing provides a higher load-carrying capacity, stiffness and damping than a single-bump air foil bearing in a heavily-loaded condition.

• Journal of Biosystems Engineering
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• 제34권2호
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• pp.71-76
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• 2009

This study was conducted to investigate the load acting on a tractor engine when it delivers the maximum power at drawbar. The results of the drawbar tests on the 5 locally-made and 14 imported tractors conducted at NIAE in 2004, and the 15 tractors tested at OECD test stations in foreign countries were analyzed and presented by the torque load ratio, defined as a ratio of the engine torque load caused by drawbar pull to its full-load capacity, as a function of pull speed. The NIAE test results showed that the torque load ratio increased from 20 to 80% with pull speed less than 5 km/h. At speeds faster than 5 km/h, it was 80${\sim}$110% regardless of the pull speed. However, the OECD test results showed that the torque load ratio was evaluated mostly to be 70${\sim}$90% in the entire pull speed range. The same trend was also shown for the maximum drawbar load. The difference in the torque load ratio may be attributable to bias-ply tires for locally-made and some imported tractors. It is also suggested that the input torque load may be increased safely up to 120% of the full load capacity of the tractor engine for an accelerated life test of tractor transmissions.

• 한국도로학회논문집
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• 제8권3호
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• pp.21-28
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• 2006

Field or laboratory wheel tracking tests have been employed for the evaluation of the rutting potential of asphalt paving mixtures. Compared to field tests, laboratory wheel tracking tests are much less expensive and more manageable for most road projects. However, most test laboratories are not equipped to perform such tests because there does not exist any standard test procedure, and the required equipment is rather expensive. Futhermore, the size of test specimens and the relatively large quantity of test mixture required present difficulties for laboratory specimen mixing and compaction. This paper describes a project conducted to study the feasibility of replacing wheel tracking testsby a repeated-load creep test for rutting potential evaluation. Comparisons were made between the results of the two tests for different test temperatures, loading speeds and applied pressures. Three types of asphalt mixtures were studied in the test program. Favorable conclusions concerning the use of the repeated-load test for rutting potential evaluation were drawn based on the findings of the experimental test results. The correlation between the two types of tests was found to be good for all threeasphalt mixtures. Adopting the repeated-load creep test would lead to cost savings since it employs standard test equipment already available in most laboratories. It would also result in substantial time savings due to the much smaller quantity of mix needed, and the ease in specimen preparation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.939-950
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• 2011

In this study, the load test of rubber tire bogie for monorail type LRT. Bogie for rolling stock in safety operation of the vehicle as an essential core unit before applying to the vehicle safety and reliability should be tested sufficiently. Rubber tire monorail type bogie compared to the traditional bogie wheel lots of formats, the complexity of the load acting static load test, the bogie of the vehicle operation conditions by structural analysis by considering the loading conditions was evaluated by calculating. Test methods and evaluation criteria based on urban rail vehicle performance testing by applying the test were welded parts and materials for the results leading to material fatigue endurance test by applying the result of evaluating the structure has been identified as safe.

• Journal of Advanced Marine Engineering and Technology
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• 제27권6호
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• pp.776-782
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• 2003

This paper describes a newly developed double squirrel cage induction motor in which the rotor is located outside the stator. The outside rotor type brushless dc motor has been used for VTR's head drum and PC's cooling fan, but this kind of induction motor has not been developed yet. The parameters of outside rotor type induction motor were measured from the locked rotor test and no load test. It is possible to determine the parameters which are presented in the steady-state equivalent-circuit of the outside rotor type induction motor. Load test of induction motor was carried out using a dynamometer. For the characteristics of torque, efficiency, power factor and output. the developed double squirrel cage induction motor is compared with the ordinary induction motor It is believed that the results of this paper can be used for the development of the outside rotor type induction motor.

• 한국정밀공학회지
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• 제32권7호
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• pp.591-595
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• 2015

The roller rig tester for safety performance evaluation of wheel derailment is a test facility which can give the test load condition to the test wheel, similar to the actual dynamic condition in actual running condition. This study describes the evaluation result on the durability of the resilient wheel equipped with the ring damper and the damping material, and installed in the half part of a full scaled bogie in combination with the primary spring when it rotates under the dynamic condition. The evaluation result on durability of resilient wheel after load test of 2 million cycles shows that the safety of wheel is not affected by the applied load in visual inspection and nondestructive test, however, in the bolt used for fastening the ring damper to the wheel the loosening was found. Accordingly the use of self-locking nut and washer is recommended.

• 한국철도학회논문집
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• 제8권6호
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• pp.566-572
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• 2005

This paper describes the results of structural analysis and loading test of a bogie frame. The purpose of the analysis and test is to evaluate the safety and functionality of the bogie frame under maximum load. The bogie system consist of the bogie frame, suspensions, wheel-sets, a brake system and a transmission system. Of these components, the bogie frame is the major components subjected to the vehicle and passenger loads. The evaluation method used the JIS E 4207 specifications throughout the FEM analysis and static load test. The test results have shown the bogie frame to be safe and stable under design load conditions.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2002년도 추계학술대회 논문집(I)
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• pp.92-97
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• 2002

This paper describes the result of carbody and vibration test for freight car. The purpose of the test is to evaluate an safety which carbody structure shall be considered fully sufficient rigidity so as to load a freight car under maximum load and operating condition on line track. The test carbody is constructed by RS korea co., LTD. in accordance with KNR specification. The test cases of the carbody is tested the vertical load and compressive load to verify the strength and stiffness. The vibration test is tested for analysis and evaluation of vibration, to allow for the fact that mechanical vibration in railway vehicles have specific characteristics.