• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
• /
• pp.222-225
• /
• 2006

Pull-off test is widely used to evaluate bond performance between concrete and FRP composite. However, reliability of experiment result declines due to many difference between test methods of each national standards. This study analyzed problems of various existing test methods for pull-off test and suggested standardized test method. In addition, since tensile strength of concrete is smaller than bond strength of epoxy resin, maximum bond strength of epoxy resin shall be limited within tensile strength of concrete. Alternative testing method, therefore, which decrease FRP adhesion areas than concrete adhesion areas is suggested to widen test range of bond strength in pull-off test. In the experimental results, bond performance can be estimated up to two times of tensile strength of concrete by reducing FRP adhesion areas by 1/3.

• Structural Engineering and Mechanics
• /
• 제85권2호
• /
• pp.265-274
• /
• 2023

The spherical steel bearings (SSBs) has been gradually replaced traditional rubber bearings and extensively applied to high-speed railway (HSR) bridges in China, due to their durability and serviceability. Nevertheless, SSB is generally simplified to the ordinary constraints in the finite element model, which cannot reflect its detailed mechanical characteristics, especially its seismic performance. To provide a more precisely simulation, an innovative and simplified finite element simulation method is proposed and the combined element group is developed in ANSYS. The primary parameters were determined by means of the performance test of SSB. The finite element model of SSB applied to a single-span HSR simply supported girder bridge was established through the proposed method. The seismic performance of the SSB was further investigated. A shake table test was conducted to evaluate the accuracy of the proposed simulation method. It is found that the numerical results could have a good agreement with the experiment, namely, the proposed method is feasible and efficient.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제18권1호
• /
• pp.80-86
• /
• 2018

Purpose: This article provides a mathematical model for the accelerated degradation test when the performance degradation characteristic follows the lognormal distribution. Method: For developing test plans, the total number of test units and the test time are determined based on the minimization of the asymptotic variance of the q-th quantile of the lifetime distribution at the use condition. Results: The mathematical model for the accelerated degradation test is provided. Conclusion: Accelerated degradation test method is widely used to evaluate the product lifetime within a resonable amount of cost and time. In this article. a mathematical model for the accelerated degradation test method is newly developed for this purposes.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
• /
• pp.1121-1124
• /
• 2004

Aging test to estimate life property of polymer insulator is executed through several international standard such as IEC 61109 and CEA tracking wheel test, but is not getting clear conclusion yet. There are two methods in the diagnosis method of polymer insulator such as off-line and on-line. The diagnosis methods in off-line are external condition analysis by the eye, contaminant analysis on surface, surface analysis, pollution withstand voltage test, power frequency flashover voltage test, lightning impulse flashover test, tensile fracture load test and flexural load test. The diagnosis methods in off-line most are the method for virgin and last aged sample. However, the diagnosis method in on-line is method that can be evaluate sample state as progressing continuously aging test in beginning, The diagnosis method in on-line is arranged as following: leakage current measurement, electric field, surface state investigation, thermal image, emitting light measurement and then so. In this paper, the tracking performance of polymer insulator with salt solution which is added surface active agent. The diagnosis of insulator sample has been analyzed by leakage current and visual examination.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2011년도 춘계학술대회 논문집
• /
• pp.1449-1450
• /
• 2011

• 한국산업정보학회논문지
• /
• 제11권3호
• /
• pp.59-68
• /
• 2006

Recently, introduction of Open Source Software into informatization of the government and public sector has been actively examined, however, Open Source Software is being rarely adopted due to the lack of verified and reliable data with regard to the criteria, process, performance and stability for introduction of Open Source Software. In this paper, the process, method and plan for performance verification for introduction of Open Source Software into mission critical systems of the government and public sector are suggested in order to solve the aforesaid problem Specially, a test system to judge whether or not to adopt Open Source Software in school affairs system of the NEIS(National Education Information System) of the Korean government was set up, and the method and process of performance verification by stage in addition to feasibility study were applied to the test system for verification. Based on the result of performance evaluation in the test system, the application of Linux to school affairs system of the NEIS is being successfully practiced. It is expected that this study will be a guideline to technical review process and performance verification method as necessary to introduce Open Source Software into the mission critical systems of government and public agencies.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2009년도 춘계학술대회 논문집
• /
• pp.223-228
• /
• 2009

Cooling and heating equipments of railroad passenger cabin is one of the most important part in keeping the good thermal comfort of the passengers. The bad performance of these equipments usually results in the comfort of the passengers. However, there is no testing method for cooling and heating equipments during manufacturing the passenger car, and calculation method is frequently used. Many railroad operators spend a lot of money for the maintenance. In this study, a new environmental performance test for railroad passenger cabin was suggested. The temperature of the chamber will be changed from $-40^{\circ}C$ to $60^{\circ}C$. The performance test of cooling and heating equipment in controlling the passenger cabin temperature was carried out under various temperature condition. The testing method to investigate the effect of artificial sunlight irradiation on the passenger cabin temperature was also suggested.

• 대한기계학회:학술대회논문집
• /
• 대한기계학회 2004년도 추계학술대회
• /
• pp.372-376
• /
• 2004

In this paper, the standard test methods at low temperature of rubber suspension components of railway vehicle are investigated and reviewed. In order to connect the TKR(Trans-Korean Railway)-TSR(Trans-Siberian Railway), it is necessary to evaluate the performance of rubber suspenion components of railway vehicle. In the current Korean Standard, the test method at low temperature of railway vehilce components and the test method of rubber bellows of air spring are specified. But, the specified test temperature is higher than the the operating temperature of TSR railway. So, the in-depth research for the test method and performance evaluation technique of rubber suspension component at low temperature is necessary and current KS code should be adjusted.

• 재활복지공학회논문지
• /
• 제4권1호
• /
• pp.9-14
• /
• 2010

인구의 고령화와 국민의 소득증대에 따라 정보통신기술을 활용한 새로운 형태의 보건의료서비스인 유헬스케어에 대한 관심과 보급이 증가되어 가고 있어 이러한 용도의 유헬스 의료기기의 안전성 확보를 위한 사용환경을 고려한 안전성 및 성능 평가방법이 필요하다. 본 연구에서는 유헬스의료기기와 관련된 국제규격(IEC)과 국내규격(KS)을 참고하여 유헬스케어의료기기의 사용환경에 대한 안전성을 평가할 수 있는 기준 및 방법과 전원문제등을 고려한 필수성능을 평가할 수 있는 기준 및 방법을 개발하였다.

• 한국신뢰성학회지:신뢰성응용연구
• /
• 제13권1호
• /
• pp.11-18
• /
• 2013

For a reliability assessment of machinery parts, accurate performance test, environmental test, life test, etc. are required on the sample. In the performance test conditions of various machinery parts, some problems happen such as needs to rise temperature rapidly with large flow of oil having very low thermal conductivity and to measure very high torque or tiny torque, etc. This study brings out the method to apply heat to rise temperature for large flow of oil without chemical change in a performance test of oil cooler. To measure large scale of torque in a performance test of planetary gearbox of excavator, the method of torque measurement is proposed by replacing the large torque meter priced very expensive. To measure very small torque on lubricated friction, a methode of force balance type test mechanism is introduced for tests of piston assembly.