• 한국신뢰성학회지:신뢰성응용연구
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• 제15권3호
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• pp.154-162
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• 2015

We have performed accelerated photo-degradation test using a 10-Sun level high irradiance $Weather-Ometer^{(R)}$ (10-Sun Ci5000) in an attempt to study acceleration and correlation between accelerated and service conditions for ink-jet ink. The accelerated test was used to predict lifetimes of ink-jet ink through the calculation of scaling factor for intensity of irradiance and duration of usage combined with estimation of lifetime distribution and inverse power model as a life-stress model. The lifetimes and acceleration factors for foreign and domestic inks were compared with each other. The results showed that the failure mechanisms and life-stress models for ink-jet ink were different among the color of ink which means that we might be in need of further study by color of inks.

• 동력기계공학회지
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• 제16권2호
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• pp.43-48
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• 2012

Generally accelerated life test is well known as one method to reduce reliability qualification test period. This test is conducted under the higher stress condition than normal condition. So it can save the test time by calculating the acceleration factor from the relationship between the worst stress condition and normal condition. This paper investigates the worst stress condition for the accelerated life test to increase the acceleration factor. Especially, we focused on the method to obtain effective acceleration factors under the worst stress condition. Moreover, we considered how to decide the worst stress condition by looking for the operating limit of this system. The acceleration factor can be estimated from the ratio of the kinematic viscosity in the normal condition and the worst stress condition, the lowest temperature, by using Arrhenius relationship. Through some experiments for a refrigerator's compressor, we were able to confirm how to increase acceleration factors and how to reduce the reliability qualification test period with minimum samples.

• 한국소음진동공학회논문집
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• 제18권3호
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• pp.323-334
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• 2008

According to the delivery condition, the breakage of a product occurs when it is delivered to the customers. Therefore product's makers evaluate the durability under the delivery process by accelerated life testing. In order to conduct this accelerated life testing accurately, it is very important to identify the acceleration-factor exactly between on-road and accelerated life test condition. In this paper, the acceleration-factor is identified by applying linear damage summation law, rain-flow cycle counting and Dirlik theory under the conditions of the random vibration. And approximated FEM model of the connecting-pipe to the compressor is developed for fatigue analysis. This model is finally verified by comparing the experiment results to the numerical analysis results.

• 한국전기전자재료학회논문지
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• 제32권6호
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• pp.490-495
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• 2019

This study performs the thermal aging of chlorosulfonated polyethylene (CSPE) for 807.36 and 1,614.48 hours at $110^{\circ}C$, which is equivalent to 40 and 80 years of aging at $50^{\circ}C$ in nuclear power plants, respectively. Flat-type CSPEs were soaked in seawater for five days and then dried for five days at room temperature. Furthermore, the soaked CSPEs were cleaned for 5 days with fresh water and dried for 1,100 days at room temperature. Through this process, the log IV of the CSPEs decreases, whereas the dissipation factor of the CSPEs increases as thermally accelerated aged years increase at the measured frequency. Although the phase degree of the response voltage versus excitation voltage of the CSPEs increases, that of the response current versus excitation voltage decreases with the thermally accelerated aging. The thermal conductivity of the CSPEs increases slightly, but the thermal diffusivity does not vary with the thermally accelerated aged year increase. The displacement of the compressive strength of the CSPEs decreases gradually as the thermally accelerated aged years increase.

• Journal of the Korean Data and Information Science Society
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• 제7권1호
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• pp.37-46
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• 1996

계단충격가속수명시험에서 얻은 자료를 토대로 통계적 추론을 위해 가정하는 수명분포에 대한 적합도 검정을 Kolmogorov-Smirnov, Cramer-von Mises, Anderson-Darling과 같은 비모수적 검정통계량들을 이용한 검정절차를 제안하고, 각 통계량들을 검정력 측면에서 비교하고자 한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
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• pp.1945-1947
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• 2005

This study considers find out best accelerated life testing and lifetime prediction of electrolytic capacitors. We proved about relation between failure and deterioration mechanism from last thesis. Beside we performed test that temperature and voltage press higher than allowance specification. Failure distribution acquired from those test. And wiebull function and Minitab program applied to accelerated constant and lifetime by means of calculation. At the result, goodness of fit affect to weibull function and acceleration factor therefore fitting is important factor in reliability testing.

• 공업화학
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• 제28권1호
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• pp.35-41
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• 2017

외부에 노출된 재료는 자외선, 열, 온도, 습도 등의 다양한 환경 인자에 의해 성능저하가 일어나게 되며, 열화속도 및 사용수명에 대한 예측은 매우 중요한 문제이다. 본 연구에서는 가장 많이 사용되고 있는 색상 중 흰색, 초록색 재귀반사시트를 가지고 미국 아리조나, 인도 첸나이, 프랑스 세너리, 한국 서산 등 4개 지역에서 옥외폭로시험 및 제논아크촉진시험을 통하여 재귀반사시트 반사성능의 변화율을 측정하였다. 서산지역 및 제논아크 촉진시험을 통하여 얻어진 반사성능 값을 통해 회귀분석을 이용하여 가속계수를 구하였다. 또한, solar uv 프로그램을 이용하여 다양한 기후지역별 가속계수를 구할 수 있었으며, 그 결과 서산지역을 기준으로 프랑스 세너리 1.04배, 미국 아리조나 1.82배, 인도 첸나이 1.92배의 가속계수를 확인할 수 있었다.

• 대한안전경영과학회지
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• 제10권3호
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• pp.73-79
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• 2008

Display's life time is defined as the time of 50% luminance drop. It was used luminance and temperature as accelerated factor to accelerated lifetime at test. When it's working jule-heat is generated and device's temperature is growing as any temperature because OLED is self-luminance display device. So we decided temperature condition is 25, $70^{\circ}C$, and luminance condition is $60{\sim}300cd/m^2$ in test. It's assumed accelerated lifetime model by result of the test.

• 한국신뢰성학회:학술대회논문집
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• 한국신뢰성학회 2004년도 정기학술대회
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• pp.129-137
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• 2004

This paper presents an accelerated life test for burnout of tungsten filament of incandescent lamp. From failure analyses of field samples, it is shown that their root causes are local heating or hot sports in the filament caused by tungsten evaporation and wire sag. Finite element analysis is performed to evaluate the effect of vibration and impact for burnout, but any points of stress concentration or structural weakness are not found in the sample. To estimate the burnout life of lamp, an accelerated life test is planned by using quality function deployment and fractional factorial design, where voltage, vibration, and temperature are selected as accelerating variables. We assumed that Weibull lifetime distribution and a generalized linear model of life-stress relationship hold through goodness of fit test and test for common shape parameter of the distribution. Using accelerated life testing software, we estimated the common shape parameter of Weibull distribution, life-stress relationship, and accelerating factor.

• 한국신뢰성학회지:신뢰성응용연구
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• 제11권3호
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• pp.281-291
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• 2011

This paper presents an accelerated life test of booster pump for home water purifier. The failure analysis shows that decreased flux due to the plastic deformation of bypass spring adjusting pressure is the predominant failure mechanism. An accelerated life test is designed and implemented to estimate the lifetime of the booster pump. Temperature, water pressure and voltage are selected as accelerating variables through the technical review about failure mechanism. It is assumed that the lifetimes of booster pumps follow lognormal distribution and the combination model of temperature and non-thermal stresses holds. The life-stress relationship, acceleration factor, and $B_{10}$ life at design condition are estimated by analyzing the accelerated life test data.