• Title/Summary/Keyword: Durability tests

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COMPUTATIONAL DURABILITY PREDICTION OF BODY STRUCTURES IN PROTOTYPE VEHICLES

  • Kim, H.-S.;Yim, H.-J.;Kim, C.-B.
    • International Journal of Automotive Technology
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    • v.3 no.4
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    • pp.129-135
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    • 2002
  • Durability estimation of a prototype vehicle has traditionally relied heavily on accelerated durability tests using predefined proving grounds or rig tests using a road simulator. By use of those tests, it is very difficult to predict durability failures in actual service environments. This motivated the development of an integrated CAE (Computer Aided Engineering) methodology for the durability estimation of a prototype vehicle in actual service environments. Since expensive computational costs such as computation time and hardware resources are required for a full vehicle simulation in those environments with a very long span of event time, the conventional CAE methodologies have little feasibility. An efficient computational methodology for durability estimations is applied with theoretical developments. The effectiveness of the proposed methodology is shown by the comparison of results of the typical actual service environment such as the city mode with those of the typical accelerated durability test over the Belgian road.

Thermal Barrier Coating Durability Testing Trends for Thrust Chamber of Liquid-propellant Rocket Engine (액체로켓엔진 연소기 열차폐코팅 내구성 시험 기술동향)

  • Lee, Keum-Oh;Ryu, Chul-Sung;Lim, Byoung-Jik;Choi, Hwan-Seok
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.1
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    • pp.103-115
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    • 2013
  • Durability testing method trends of the thermal barrier coating(TBC) for the combustion chamber of the liquid-propellant rocket engine have been investigated. Many types of the durability testing method such as the mechanical tests to measure surface cohesion force, the thermal fatigue tests with laser, furnace, burner or plasma, the small scale combustion tests using injectors, and the thermo-mechanical fatigue tests were observed. The TBC with sufficient durability can be selected for the use of combustion chamber through such specimen-level tests and the durability can be verified by the tests using the real scale combustion chambers.

Thermal Barrier Coating Durability Testing Trends for Thrust Chamber of Liquid-propellant Rocket Engine (액체로켓엔진 연소기 열차폐코팅 내구성 시험 기술동향)

  • Lee, Keum-Oh;Ryu, Chul-Sung;Lim, Byoung-Jik;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2012.05a
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    • pp.603-615
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    • 2012
  • Durability testing method trends of the thermal barrier coating(TBC) for the combustion chamber of the liquid-propellant rocket engine has been investigated. Many types of the durability testing method such as the mechanical tests to measure surface cohesion force, the thermal fatigue tests with laser, furnace, burner or plasma, the small scale combustion tests using injectors, and the thermo-mechanical fatigue tests were observed. The TBC with sufficient durability can be selected for the use of combustion chamber through such specimen-level tests and the durability can be verified by the tests using the real scale combustion chambers.

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Feasibility of utilizing oven-drying test to estimate the durability performance of concrete

  • Chen, How-Ji;Tang, Chao-Wei;Peng, Hsien-Sheng
    • Computers and Concrete
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    • v.8 no.4
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    • pp.389-399
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    • 2011
  • The increasing concern for reinforced concrete structure durability has been justifying in many ways in the last few decades. However, there is no perfect durability test method till now. In this research an alternative method, which is based on the cumulative moisture loss percent of the concrete specimens after oven-drying, was proposed to estimate the durability performance of the concrete. Two temperatures were considered for the oven-drying tests: $100^{\circ}C$ and $200^{\circ}C$. Test results showed that oven-drying at $200^{\circ}C$ was obviously an unsuitable procedure to preserve the fragile microstructure of cement-based materials. By contrast, experimental results through oven-drying at $100^{\circ}C$ allowed estimating the moisture loss percent of cement-based materials in a more rational manner. Moreover, the magnitudes of the cumulative moisture loss percent obtained from oven-drying tests at $100^{\circ}C$ for 48 hours have good correlations with the data of other well-known methods, namely, electrical resistance test, water permeability test, and mercury intrusion porosimetry test. This investigation established that regarding the oven-drying test as one of the tests for evaluating the potential durability of concrete is considerably practicable.

A study on the vibration durability test for the energy harvesting part of vehicle (에너지 활용 부품의 진동내구 평가기법 연구)

  • Ju, Hyung-Jun;Kim, Chan-Jung;Lee, Gee-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.587-588
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    • 2014
  • Studies that the vehicle exhaust system applied by the TEG(thermal electric generator) are actively in progress in order to improve the fuel efficiency of the vehicle. Vehicle exhaust system is on a poor vibration condition, it is susceptible to TEG. This paper is about the development of vibration durability test of TEG mounted on a vehicle exhaust system. Vehicle driving tests are performed to measure the vibration condition of the vehicle exhaust system. The vibration durability test mode of TEG is evaluated using equivalent vibration energy method. The vibration durability tests of TEG are performed using the multi-axial vibration simulation table.

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A Study on Durability Test Method of Vehicle Suspension Systems (차량 현가장치의 내구성 시험에 관한 연구)

  • 백운경
    • Journal of the Korean Society of Safety
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    • v.10 no.2
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    • pp.24-31
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    • 1995
  • This paper shows the fatigue durability test method for vehicle suspension systems. Durability should be assured for the safe driving during vehicle life cycle. A computer simulation for the vehicle dynamics was used to obtain dynamic loads that were required for the fatigue durability test. Durability tests were done for an Important load-carrying component of the suspension system. Stress analyses using stresscoat and strain gages were also done for the component. This study demonstrated an effective method for the fatigue durability test.

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Current Status and Analysis of Durability for Buildings Long Neglected after Construction Discontinuation in Jeju (제주지역 공사중단 건축물의 현황조사 및 내구성 분석)

  • Han, In-Deok;Kim, Doo-Seong;Jang, Myunghoun
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.4
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    • pp.441-452
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    • 2023
  • Buildings that have been long neglected can suffer severe durability reduction due to factors such as rebar rust and concrete quality deterioration resulting from exposure to outside air. Furthermore, the issues associated with these suspended buildings, including safety accidents, social crimes, and environmental pollution, are becoming increasingly serious. This study investigates the current status of these buildings in the Jeju area, identifies the problems, and examines the durability of the structure in a specific location to assess the possibility of future use. Aesthetic surveys(visual and slope inspections) as well as non-destructive tests(compressive strength tests, neutralization tests, and rebar detection tests) were conducted to assess durability. The analysis revealed that the structure maintained satisfactory durability and the building's condition was good in comparison to the years of neglect.

Strength and durability characteristics of biopolymer-treated desert sand

  • Qureshi, Mohsin U.;Chang, Ilhan;Al-Sadarani, Khaloud
    • Geomechanics and Engineering
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    • v.12 no.5
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    • pp.785-801
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    • 2017
  • Biopolymer treatment of geomaterials to develop sustainable geotechnical systems is an important step towards the reduction of global warming. The cutting edge technology of biopolymer treatment is not only environment friendly but also has widespread application. This paper presents the strength and slake durability characteristics of biopolymer-treated sand sampled from Al-Sharqia Desert in Oman. The specimens were prepared by mixing sand at various proportions by weight of xanthan gum biopolymer. To make a comparison with conventional methods of ground improvement, cement treated sand specimens were also prepared. To demonstrate the effects of wetting and drying, standard slake durability tests were also conducted on the specimens. According to the results of strength tests, xanthan gum treatment increased the unconfined strength of sand, similar to the strengthening effect of mixing cement in sand. The slake durability test results indicated that the resistance of biopolymer-treated sand to disintegration upon interaction with water is stronger than that of cement treated sand. The percentage of xanthan gum to treat sand is proposed as 2-3% for optimal performance in terms of strength and durability. SEM analysis of biopolymer-treated sand specimens also confirms that the sand particles are linked through the biopolymer, which has increased shear resistance and durability. Results of this study imply xanthan gum biopolymer treatment as an eco-friendly technique to improve the mechanical properties of desert sand. However, the strengthening effect due to the biopolymer treatment of sand can be weakened upon interaction with water.

Durability Characteristics of Controlled Low-Strength Materials using Bottom Ash (Bottom ash를 함유한 저강도 고유동 재료의 내구성능)

  • 원종필;이용수
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.1203-1206
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    • 2001
  • The main intent of this research is to determine the feasibility of utilizing bottom ash as CLSM(Controlled Low-strength Materials). The durability tests including permeability, repeated wetting and drying, freezing and thawing for bottom ash CLSM were conducted. Laboratory test results indicated that CLSM using bottom ash has acceptable durability performance.

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The Testing Methods of the Fire and the Electric Shock on the Electric Pad Using the House (가정용 전기매트에 대한 화재 및 감전 시험법에 관한 연구)

  • Jang, In-Hyeok;Lee, Chang-Hoon;Lee, Young-Joo;Lim, Houng-Woo
    • Journal of Applied Reliability
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    • v.14 no.3
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    • pp.169-175
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    • 2014
  • In this paper, the evaluating test methods of the fire and the electric shock on the Electric pad using the house is proposed. We analyzed electric pad using magnetic shielded type hot wire because electric pad using the magnetic shielded type hot wire generally be used in the home. We analyzed FMEA in order to analyze the mechanism of the fire and the electric shock of the electric pad and designed testing methods (Durability tests on the environment, Mechanical durability tests, Electrical durability tests) obtained through the two-step QFD and tested. We verified the evaluating test methods of the fire and the electric shock on the Electric pad using the house through the analysis of the test results.