• Journal of the Korean Society for Precision Engineering
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• v.20 no.11
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• pp.127-133
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• 2003

Pin-on-disk and hardness tests using mechanical components of M-20J aircraft braking system were performed to identify the friction and wear characteristics. The intention of this work was also to analyze a 5-year term maintenance record of an M-20J aircraft. used for flight training at Hankook Aviation University, and to determine the reliability of the brake system of an M-20J aircraft. The mean wear coefficients of the lining sliding against the brake disk were compared between the test and reliability estimation to obtain a predictive wear model.

• Journal of Applied Reliability
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• v.16 no.2
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• pp.125-133
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• 2016

Purpose: The purpose of this study is to evaluate durability of platform safety step system in railway. Method: We performed finite element analysis & durability analysis of platform safety step system with VPD (Virtual Product Development) techniques and examined the durability standard & qualification life through the rig test during no failure test time in reliability qualification test. We continued to test 1 million cycles in KRS (Korea Railway Standard) for system's robust design performance. Result: FEM analysis results are 14.9MPa & 14.7MPa of pin-joint, pivot and durability analysis result is above 1 million cycles. we calculated theoretically no failure test time 855,000 cycles and through the 1 million cycles durability rig test in KRS standard we confirmed product quality. Conclusion: This platform safety step system was designed very safe in terms of a mechanical strength & durability.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2004.04a
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• pp.77-82
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• 2004

This study presents reliability assessment of merchant ships with focus on hull girder ultimate limit state, taking into account the time-dependent effects of corrosion, fatigue cracking and local denting. Some considerations for establishing a reliability-based repair and maintenance scheme are also made so as to keep a ship's hull girder strength reliability at an acceptable level even later in life.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1538-1541
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• 2005

For reliability evaluation of AC-PDP, one of the most important factor is sealing property. In this paper, the reliability evaluation test method of the commercialized sealing glass frit in AC-PDP was studied. 6 inch AC-PDP panels were tested for evaluation of sealing glass frit by vibration shock test, thermal shock test, non -destructive X-ray inspection, residual stress inspection and residual gas detection. These test methods are proposed as a standard for testing the reliability of sealing glass frit. The main failure mode of sealing glass frit in AC-PDP seems to be the crack propagation from thermal cycling rather than mechanical factor.

• Smart Structures and Systems
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• v.22 no.2
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• pp.193-200
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• 2018

From the viewpoint of engineering applications, the prediction of the failure of bogies plays an important role in preventing the occurrence of fatigue. Fatigue is a complex phenomenon affected by many uncertainties (such as load, environment, geometrical and material properties, and so on). The key to predict fatigue damage accurately is how to quantify these uncertainties. A Bayesian model is used to account for the uncertainty of various sources when predicting fatigue damage of structural components. In spite of improvements in the design of fatigue-sensitive structures, periodic non-destructive inspections are required for components. With the help of modern nondestructive inspection techniques, the fatigue flaws can be detected for bogie structures, and fatigue reliability can be updated by using Bayesian theorem with inspection data. A practical fatigue analysis of welded bogies is utilized to testify the effectiveness of the proposed methods.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.7 no.2
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• pp.69-73
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• 1998

With increased loads in steered wheels and wider section tires the effort required at the steering wheel makes the driver's job very tiring and difficult. Improvements such as an increase in the mechanical efficiency of the steering system or lower steering box ratios help the reduce driver fatigue. Now using of power steering is increasing. It needs to be considering parts size of steering system as using power steering. This paper presents adjust part size of steering system form estimating reliability according to reducing torque under the dynamic load, In this paper, the spider of universial joint is selected to prove relation between steering and power steering reliability.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.3
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• pp.507-515
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• 2012

Recently RFID(Radio Frequency Identification) technology advances in wireless communication technologies are bringing new challenges. But RFID tag packaging technology has been lagging compared to the demand, so this technology is being required to improve productivity and reliability. This study is performed on FMEA, reliability at development level and analysis failure mode through environment and mechanical test. Robust design is applied to search the optimized condition of factor and RFID tag packaging should be satisfied with high MTTF.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.6
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• pp.90-96
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• 1998

Helical gear system is widely used to transmit heavy duty power with harmonies and silences between parallel shafts. This paper predicts a life with Weibull distribution and estimates a reliability based on recycle principle of helical gear systems. 2-parameter Weibull distribution is generally adopted to estimate the mechanical life and the reliability of most gear systems, because this Weibull distribution is proper to explain a characteristics or a life of parts of gear systems with linearity of probability density data on weibull data sheet. For a high reliability, this paper estimates a number of overhaul times and a number of needed substitutes (exchange attachment,1 or parts) with following renewal theory, One is make an exchange of whole module include failure attachments/parts and second estimating method is only exchange of a failure attachments / parts.

• Journal of Korea Society of Industrial Information Systems
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• v.7 no.2
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• pp.33-39
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• 2002

Accelerated life testing of a car is used to get information quickly on its life distribution. Test cars are no under severe conditions and fail sooner than under usual conditions. A model is fitted to the accelerated failure times and then extrapolated to estimate the life distribution under usual conditions. This paper presents an accelerated test md the reliability growth theory, and applies it to some subsystems of cars during their prototype and pilot testing. The data presented illustrates explicitly the prediction of the reliability growth in the product development cycle. The application of these techniques is a part of the product assurance function that plays an important role in product reliability improvement.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.150-156
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• 2009

The oil pressure switch(OPS) for automobile is very important part to prevent an overheated engine and other problems by checking the operation of an engine oil system and displaying oil signs on a dashboard. OPS is the part that receives various stress caused by temperature, vibration, and corrosion in an engine room. Regarding existing steel OPS cases, there occur field errors due to the rust, and much concern comes from the low anticorrosion caused by CR6+ Free according to the restrictions of heavy metals. Therefore, the study analyzed average life, the failure rate, and reliability through the tests of performance according to temperature changes, mechanical strength, and run-test in order to confirm if the use of the oil pressure switch with Al of anti-corrosion can improves the reliability, instead of the existing steel products.