• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2001년도 추계학술대회 논문집 전기물성,응용부문
• /
• pp.155-157
• /
• 2001

Various types suspension insulators made of toughness glass or porcelain are used in the power transmission. And, Insulators are continually subject to mechanical and electrical stresses which depend on the characteristics of the line. The main factor that influence the increase in reliability of insulators. In operation is the capacity of the design to withstand the certain load over a long time, the mechanical strength of the insulators. This paper describes the results of a study on the stress analysis of suspension insulator based on the finite element analysis using NASTRAN. And, the mechanical strength was evaluated through such as kinds of pin type.

• 대한설비공학회지:설비저널
• /
• 제17권3호
• /
• pp.230-237
• /
• 1988

An experiment was carried out to study the condensation heat transfer enhancement of horizontal circular cylinders with varying outside surface configurations. The refrigerant used is Freon-22 and the test condensing temperature is 34.1C. Pin-finned tube shows about 2.5-3.5 times higher overall heat transfer coefficient compared to that of smooth surface tube, thus has larger encomic benifit for condenser design. The condensation heat transfer coefficient was shown to increase as the fin-pitch of the pin-finned tube decreases for film Reynolds number larger than 100.

• The Korean Journal of Ceramics
• /
• 제2권4호
• /
• pp.212-215
• /
• 1996

This paper focuses the strength and wear resistance of CVD diamond films. The strength of free-standing CVD diamond films synthesized by microwave plasm CVD, DC plasma CVD, RF plasma CVD and arc discharge plasma jet CVD has been measured by three-point bending test. The wear resistance of CVD diamod films has been evaluated by the pin-on-disk type testing. diamond films coated on the base of sintered tungsten carbide pin by hot filament CVD have been rubbed with a sintered diamond disk in muddy water. Volume removed wear of CVD diamond has been compared with stellite, WC alloy and bearing steel.

• 한국정밀공학회지
• /
• 제17권3호
• /
• pp.149-157
• /
• 2000

Tool wear in the shearing process such as blanking, piercing and trimming is very important, because it has great effects on the dimensional accuracy, working efficiency and economy. Most of tools in the shearing process have the coated layer at surface fur good wear and corrosion resistance. When the surface of tool is teated, the wear Phenomena of coated surface layer and inner layer may be different. This paper describes a computer modelling technique by the finite element method in order to investigate the wear mechanism and to predict the wear profile of Ti-N coated tool in piercing process according to the volume of Production. Wear coefficients of the coated layer and inner layer are obtained through Pin-on-Disk wear test, respectively. To verify the effectiveness of the suggested technique, the technique is applied to wear analysis in piercing recess of piston pin and simulation results are compared with experimental ones.

• Tribology and Lubricants
• /
• 제27권2호
• /
• pp.65-70
• /
• 2011

The power servo cylinder for driving accurately turbine stop valve of an atomic power plant is necessary to do turn-over owing to a leakage of oil and a structure problem, especially, it of a power plant be in demand a high quality standard depends entirely on import. There are much problem that the AlBC be to used as a material of piston head in cylinder are caused by wear. Therefore, it is necessary to examine friction characteristics of it. In this study, wear test experiments was carried out with AlBC and SCM440, using reciprocating friction tester of pin on disk. This result was shown that the wear mechanism of AlBC on working condition is adhesive wear and the maximum temperature of infra redray thermal image of frictional surface show over 2 mm from contact surface of pin and disk.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2009년도 춘계학술대회 논문집
• /
• pp.294-297
• /
• 2009

The frictional behaviors of Cermets/Cr-Ceramics and Cu-Al coatings of piston ring were investigated. Friction tests were carried out by pin-on-disk test and materials properties of coating layer were analyzed by nano indentation tester. Higher friction coefficient was obtained at harder coating with rougher surface. In case of hard-coating, the scratch depth, width and pile-up height had close relationship with indentation hardness. So the scratch width, depth and pile-up height increases with decreasing friction coefficient. But in case of soft-coating, the friction coefficients are strongly dependent on the morphological characteristics after nano scratching more than indentation hardness.

• Composites Research
• /
• 제25권1호
• /
• pp.14-18
• /
• 2012

구조용 접착제는 알루미늄이나 복합재료 같은 가벼운 재질의 접합에 적용함으로써 자동차의 경량화를 이루어 연비 및 승차감등 성능향상에 큰 효과를 얻을 수 있다. 자동차와 같이 충돌환경에 노출이 되어있는 기계 구조물에 접착제를 적용하기 위해서는 접착제의 충격특성에 관한 연구가 필수적이다. 본 연구에서는 pin-ring 타입의 접착조인트를 이용하여 접착제의 전단 충격특성에 관한 연구를 수행하였으며, 충돌해석을 하기 위해 LS-DYNA를 사용하였다.

• 한국안전학회지
• /
• 제26권4호
• /
• pp.27-33
• /
• 2011

Forensic Engineering is the area covering the investigation of products, structures that fail to perform or do not function as intended, causing personal injury or damage to property. To investigate explosion accident of the centrifugal casting machine in terms of the forensic engineering, in this paper, the computing simulation using ADINA FSI has performed to investigate that the effect of the Check-Pin fracture by the flow phenomena and molten metal weight and the mechanical properties test of the accident Check-Pin has performed using the instrumented indentation technique. Through these studies, the safety accident that may occur in centrifugal casting machine can be minimized by performing specialized and systematic investigation of the accident cause in terms of the forensic engineering.

• 한국항공운항학회지
• /
• 제27권3호
• /
• pp.15-23
• /
• 2019

This paper contains analyses and development processes of the requirements to detect the possible intermittent failure in an old avionics backplane. Interconnections for signal transmission between electronic components, such as Pin-to-PCB, FPCB-to-FPCB, pin-to-FPCB, and pint-to-wire, were selected as the main cause of intermittent failure by analyzing target equipment and documents. The possibility of detecting intermittent failures occurring in the target equipment is verified by physics-of-failure analyses. In order to verify the occurrence of intermittent failures and their detectability, latching continuity circuit testers were manufactured and accelerated life tests were performed by applying temperature and vibration cycle in consideration of flight conditions. Through the above process, the detection requirements for the major intermittent failure in the target avionics backplane was developed.

• Journal of Information Processing Systems
• /
• 제6권2호
• /
• pp.197-208
• /
• 2010

Test scenarios can be derived based on some system models for requirements validation purposes. Model-based test suite reduction aims to provide a smaller set of test scenarios which can preserve the original test coverage with respect to some testing criteria. We are proposing to apply Formal Concept Analysis (FCA) in analyzing the association between a set of test scenarios and a set of transitions specified in a state machine model. By utilizing the properties of concept lattice, we are able to determine incrementally a minimal set of test scenarios with adequate test coverage.