• Title/Summary/Keyword: test conditions

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Severity Test of Road Surface Profile by Using the Fatigue Life Prediction Method (피로수명 예측법을 이용한 각 도로가 차량의 내구성에 미치는 가혹도 평가)

  • Jung, W.W.;Kang, S.S.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.6
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    • pp.154-161
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    • 1995
  • There are several kinds of driving conditions according to the characteristic of each vehicle diver. Automaker produces vehicle strong enough to satisfy this several driving conditions at the point of vehicle durability. In order to develop the car in a short period, Automaker engineer tests vehicle at serveral accelerated durability test roads. Before testing the vehicle durability, test engineer must know how much this test road severe than general field road which is composed of high way, city road, paved road and unpaved road. This paper suggests two types of road severity test method that is using relative fatigue life prediction method and using absolute fatigue life prediction method, and also present the merits and demerits of two test methods.

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Consideration of Geosynthetics Chemical Resistance Test for Long-Term Performance Evaluation (장기성능 평가를 위한 토목섬유 화학저항성 시험 고찰)

  • Jeon, Han-Yong;Jang, Yeon-Soo;Gong, Hak-Bong
    • Proceedings of the Korean Geotechical Society Conference
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    • 2009.03a
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    • pp.222-232
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    • 2009
  • In this study, the real site test conditions were considered and applied to suggest the improved test method for geosynthetics chemical resistance. For this, index and performance tests were done to specify and regulate the more approached test method. Accelerated model by Arrhenius equation was applied to interpretate the experimental data. Through analysis and comparison the overall experimental results, we could suggest the possibility and setup the advanced chemical resistance test method for geosynthetics.

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Adhesive Performance of Waterproofing System on Concrete Substrate with Moisture Condition (콘크리트 표면 함수비에 따른 교면방수재료의 인장접착성능)

  • 박성기;심재원;이병덕
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.05a
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    • pp.979-984
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    • 2001
  • Poor water-proofing integrity is related to many factors : site procedure, workmanship, weather. substrate conditions, installation(including asphalt application) conditions. The evaluation of adhesive properties tested by concrete surface moisture and asphalt application was based on laboratory test and observations. This report describes the pull-off test results of waterproofing systems currently used for installing and reparing for concrete bridge decks. The test results showed that the moisture condition fully affected the adhesive properties of sheet membranes and sealer but partially for liquid membranes.

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Accelerated Life Test for 1.25Gbps Transceiver (광통신용 1.25Gbps Transceiver 가속수명시험)

  • Yun, Gwang-Su;Yu, Chong-Hee;Heo, Young-Soon
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1391-1393
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    • 2008
  • In this paper, the long-term reliability for 1.25G transceiver in use of high speed optical access network is investigated. High temperature storage tests and accelerated life tests are used to long-term reliability. Accelerated aging test have been during 3,000 hour of the three accelerated aging conditions by caused high temperature stress. Mean life is assumed to follow the Arrhenius relationship and analysis from the failure data obtained in the accelerated aging conditions.

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A Study on Dynamic Test of Distance Relay for Transmission Line with the Unified Power Flow Controller Using the Real-Time Digital Simulator(RTDS) (UPFC가 연계된 선로에서 RTDS를 이용한 거리계전기의 동특성 시험에 관한 연구)

  • Jung, Chang-Ho;Kim, Jin-O
    • Proceedings of the KIEE Conference
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    • 2001.07a
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    • pp.223-225
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    • 2001
  • This paper discusses the dynamic test of distance relay on transmission line connected unified power flow controller(UPFC) using the real-time digital simulator(RTDS). Depending on operating conditions of UPFC, the trip characteristics of distance relay is influenced by the prefault conditions. In this paper, UPFC is established using the RTDS and then relay test is performed on real time.

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Validation of a 750 kW semi-submersible floating offshore wind turbine numerical model with model test data, part II: Model-II

  • Kim, Junbae;Shin, Hyunkyoung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.213-225
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    • 2020
  • Floating Offshore Wind Turbines (FOWT) installed in the deep sea regions where stable and strong wind flows are abundant would have significantly improved energy production capacity. When designing FOWT, it is essential to understand the stability and motion performance of the floater. Water tank model tests are required to evaluate these aspects of performance. This paper describes a model test and numerical simulation for a 750-kW semi-submersible platform wind turbine model-II. In the previous model test, the 750-kW FOWT model-I suffered slamming phenomena from extreme wave conditions. Because of that, the platform freeboard of model-II was increased to mitigate the slamming load on the platform deck structure in extreme conditions. Also, the model-I pitch Response Amplitude Operators (RAO) of simulation had strong responses to the natural frequency region. Thus, the hub height of model-II was decreased to reduce the pitch resonance responses from the low-frequency response of the system. Like the model-I, 750-kW FOWT model-II was built with a 1/40 scale ratio. Furthermore, the experiments to evaluate the performance characteristics of the model-II wind turbine were executed at the same location and in the same environment conditions as were those of model-I. These tests included a free decay test, and tests of regular and irregular wave conditions. Both the experimental and simulation conditions considered the blade rotating effect due to the wind. The results of the model tests were compared with the numerical simulations of the FOWT using FAST (Fatigue, Aerodynamics, Structures, and Turbulence) code from the National Renewable Energy Laboratory (NREL).

Changes in Absorbency and Drying Speed of a Quick-drying Knit Fabric by Repeated Laundering

  • Roh, Eui-Kyung;Kim, Eun-Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.12
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    • pp.2062-2072
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    • 2010
  • This research evaluates the change of the water absorbency and drying speed of a quick-drying knit fabric by repeated laundering and laundering conditions and investigates the influence of laundering conditions on the functional properties of the knit fabric. Four factors of laundering conditions were studied: detergent, water hardness, water temperature, and frequency of rotation. Knit fabrics were washed for 25 laundering cycles in a drum-type washing machine with nine different laundering conditions derived from an orthogonal array. The properties of knit fabrics were measured with a drop absorption test, a strip test, and a drying time test. Relaxation shrinkage pointed to a change in the structural characteristics of the knit fabric. Wetting time was faster and wickability was greater in the knit fabrics that underwent 5 laundering cycles; in addition, there were no obvious changes in wetting time and wickability. The detergent was the most important factor in wetting time (40.4%) and wickability (60% or above). Water hardness, water temperature and RPM had less of an effect on wetting time and wickability. There were no significant differences between the levels of laundering conditions (except for detergent) on wetting time and wickability. Drying times with neutral and alkali were slower by repeated laundering; however, there was no obvious change in drying time. Hardness, water temperature and RPM had less of an impact on drying time.

The Effects of Working Conditions on Internship Satisfaction of Hotel & Restaurant Management Students (산학 실습 근무 여건이 호텔 및 외식 전공 학생들의 산학 실습 만족도에 미치는 영향 - 전북 지역을 중심으로 -)

  • Mun, Min-Kuk;Jo, Mi-Na
    • Korean journal of food and cookery science
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    • v.25 no.6
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    • pp.725-738
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    • 2009
  • The purpose of this study was to investigate the effects of working conditions on internship satisfaction. Hotel & Restaurant management students at universities in Jeonju participated in this study. Out of 156 questionnaires, 149 were analyzed using SPSS 17.0 and descriptive analysis, frequency test, factor analysis, reliability test, chi-square, t-test, ANOVA, duncan's multiple regression analysis, correlation analysis and regression analysis were used. Based on the result of the conducting factor analysis, the working conditions were classified into 2 factors: work suitability and work environment. Internship satisfaction was classified into 3 factors: internship preference, education and work satisfaction, company satisfaction. Cronbach's alpha was calculated for the reliability of the survey instrument. Consequently, the working conditions were shown to affect internship satisfaction. Among the working conditions, work suitability had a lower effect on internship satisfaction than work environment. At the resort used in this study, the salary level was high, but the level of work environment, internship preference, and company satisfaction was low. The students wanted attend an internship program at the desired place to be hired and found that it was more important to be assigned to the desired department than having a higher salary.

Experimental and Measurement Methods for the Small-Scale Model Testing of Lateral and Torsional Stability

  • Lee, Jong-Han;Park, Yong Myung;Jung, Chi-Young;Kim, Jae-Bong
    • International Journal of Concrete Structures and Materials
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    • v.11 no.2
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    • pp.377-389
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    • 2017
  • Tests of the lateral and torsional stability are quite sensitive to the experimental conditions, such as support conditions and loading system. Controlling all of these conditions in a full-size test is a very challenging task. Therefore, in this paper, an experimental measurement method that can control the experimental conditions using a small-scale model was proposed to evaluate the lateral and torsional stability of beams. For this, a loading system was provided to maintain the vertical direction of the load applied to the beam, and a support frame was produced to satisfy the in-plane and out-of-plane support conditions. The experimental method using a small-scale model was applied successively to the lateral and torsional behavior and stability of I-shaped beams. The proposed experimental methods, which effectively accommodate the changes in the geometry and length of the beam, could contribute to further experimental studies regarding the lateral and torsional stability of flexural members.

Welded plate and T-stub tests and implications on structural behavior of moment frame connections

  • Dong, P.;Kilinski, T.
    • Steel and Composite Structures
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    • v.2 no.1
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    • pp.35-50
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    • 2002
  • A series of tests on simple-welded plate specimens (SWPS) and T-stub tension specimens simulating some of the joint details in moment frame connections were conducted in this investigation. The effects of weld strength mismatch and weld metal toughness on structural behavior of these specimens were considered under both static and dynamic loading conditions. Finite element analyses were performed by taking into account typical weld residual stress distributions and weld metal strength mismatch conditions to facilitate the interpretation of the test results. The major findings are as follows: (a) Sufficient specimen size requirements are essential in simulating both load transfer and constraint conditions that are relevant to moment frame connections, (b) Weld residual stresses can significantly elevate stress triaxiality in addition to structural constraint effects, both of which can significantly reduce the plastic deformation capacity in moment frame connections, (c) Based on the test results, dynamic loading within a loading rate of 0.02 in/in/sec, as used in this study, premature brittle fractures were not seen, although a significant elevation of the yield strength can be clearly observed. However, brittle fracture features can be clearly identified in T-stub specimens in which severe constraint effects (stress triaxiality) are considered as the primary cause, (d) Based on both the test and FEA results, T-stub specimens provide a reasonable representation of the joint conditions in moment frame connections in simulating both complex load transfer mode and constraint conditions.