• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.05a
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• pp.80-87
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• 2002

We predict the unknown cannon tube erosion rate by using observed values of the standard cannon, 155mm Howitzer Ml85. We know the standard cannon's ten erosion observation values each 400 rounds. An approximate formula fitting the erosion values of the standard cannon has been derived. Numerical simulation applying this formula to the Rauf Imam's erosion equations is presented.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.5 no.1
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• pp.19-26
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• 2006

The wear behavior as the hardness of the sliding elements on the dry wear has been investigated using a dual leaf-spring. The materials of the specimens are used as ten kinds along their hardness. In this study, both upper and lower specimens have been used the same materials. Using experimental data, we figured the relationship between wear coefficient and friction coefficient, and the relationship between wear coefficient and friction temperature. Also we combined friction temperature and friction coefficient instead of wear coefficient. We substituted this into wear equation of Archard. The result had been derived a newly wear equation in using dual leaf-spring wear system.

• Proceedings of the Materials Research Society of Korea Conference
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• 2006.05a
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• pp.35.2-35.2
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• 2006

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.581-588
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• 2020

This study examined a brake pad wear compensation method for an Electro-Mechanical Brake (EMB) using the braking test device. A three-phase Interior Permanent Magnet Synchronous Motor (IPMSM) was applied to drive the actuator of an EMB. Current control, speed control, and position control were used to control the clamping force of the EMB. The wear compensation method was performed using a software algorithm that updates the motor model equation by comparing the motor output torque current with a reference current. In addition, a simple first-order motor model equation was applied to estimate the output clamping force. The operation time to the maximum clamping force increased within 0.1 seconds compared to the brake pad in its initial condition. The experiment verified that the reference operating time was within 0.5 seconds, and the maximum value of the clamping force was satisfied under the wear condition. The wear compensation method based on the software algorithm in this paper can be performed in the pre-departure test of rolling stock.

• Tribology and Lubricants
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• v.25 no.3
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• pp.171-175
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• 2009

One of the critical issues associated with the 40mm long hollow cylinder's development and maintenance is the prediction of cylinder erosion. The actual firing test is the most accurate method to measure the cylinder erosion rate. But it costs a great deal and requires a long measurement time. Hence many empirical methods have been proposed to predict the erosion rate and life span of long hollow cylinders. An EFC formula is calculated. An approximate erosion formula for the ammunition type A is derived to interpolate 16 observation values up to 4,000 rounds. A new erosion equation and muzzle velocity formula are also suggested. Several numerical results are presented.

• 한국방재학회:학술대회논문집
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• 2009.02b
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• pp.63.2-63.2
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• 2009

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.205-206
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• 2010

This study is a result of laboratory work about abrasion of artificial lightweight concrete and normal concrete in an equal condition, although the bigger a percentage of W/B is, the more increasing artificial lightweight concrete's persentage of loss, in case of mixing Flyash, artificial lightweight concrete percentage of loss is decreasing and in case of mixing W/B 30% and Flyash 15%, the difference of artificial lightweight concrete and normal concrete's percentage of loss is about 3%, there is little difference.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.3
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• pp.27-33
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• 2008

It is shown that the rate of wear can be related to 'index of wear intensity' using a leaf-spring in the disc on disk on wear tests. Since both upper and lower specimens have used the same hardness values, equivalent hardness of 'the index of wear intensity' used the mean hardness value of specimens. This index is derived from the external variables of load, sliding speed and the hardness of the sliding pairs. The wear behavior as the hardness of the sliding elements on the dry wear has been investigated using a disc on disc configuration. The materials of the specimens are used as ten kinds along their hardness. Using experimental data, we figured the relationship between wear rate and index of wear intensity. A newly wear equation had been derived the result using a leaf-spring in disc on disc wear system.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.57-70
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• 2017

In this study, we investigated the wear measurement methods for slurry pipe applied in the field of mining and oil sand industry and theoretical equations related to the prediction of wear in slurry pipe through literature review. Average daily wear rate and wear rate per excavated distance were determined from slurry discharge pipe thickness measurement data periodically measured at the actual slurry shield TBM site in Singapore. The wear rate of slurry pipe for Bukit Timah Granite was obtained. The wear rates for G (V) grade and mixed zone were 1.5 times higher than that of G (I) to G (IV) grade. Slurry pipe wear rate tends to increase in proportion to the slurry discharge velocity. The optimal slurry pipe replacement or rotation frequency can be estimated through the selection of the pipe wear rate considering geological condition and the reasonable pipe management thickness.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.05b
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• pp.164-169
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• 2005

A.T.S.의 스위칭 구조와 접점 환경은 주로 아크 전류, 접촉 저항, 아크 시간 등의 불리적 요인이 주로 마모와 특성에 영향을 미치게 된다. 사용되는 접점 재료는 W 또는 WC-Cu 계로 형상과 크기는 전형적인 반구형 구조의 접촉으로 구동이 이루어진다. 따라서 A.T.S.용 접점의 아크 마모 특성 시험을 위한 고려 요인은 이러한 점을 고려하여 시험과 분석이 이루어 졌다. 접점의 마모 특성 실험식으로부터 실제적인 관점에서 보면 제한된 수명을 나타내는 $n_L$을 보장하기 때문에 b<1의 경우가 가장 바람직한 결과로 ATS 접점 시편의 경우 $b{\fallingdotseq}0.99$로 안정된 접점 아크 마모 특성을 갖는 것으로 판단된다. 아크 전압에 대한 모델링과 실험에서 접점 간극 거리 1<0.1mm, 아크전류 i<100A의 시험 조건에 대해 검토한 결과 ATS 접점 시편의 아크전압은 $u_a=10.2V$로 계산되었다. 이 값은 설험적인 값과 상당히 접근하는 특성을 갖는 것으로 나타났으며, 아크에 의한 마모를 억제하기 위해 첨가하는 WC 또는 W의 복합 소결로 인해 아크 에너지가 감소되는 것을 보여준다. 한편 접점의 아크 동작이 분리되는 순간의 동작 시험에서 기존 W(50%wt)-Cu(50%wt) 접점의 값과 비교하면 분리시 아크 전압은 상대적으로 낮아지는 현상은 W강화 첨가량의 증가로 인한 아크 에너지 감소의 제한성을 나타내는 것으로 사료된다.