유기피복 도금강판의 온간 딥드로잉 성형성에 관한 연구

장성호,신장모,최이천,서대교 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

The limiting drawing ratio(LDR) under uniform beating of blanks was measured at the various temperature ranges between 25℃ and 250℃ by using two different blank shapes, square and circular blanks, and six different blank sizes with the drawing ratios(DR) of 2.4 to 2.7. The orgaric coated steel skeets(SCP3CJ-3K/3K) of 0.7mm thickness were used. The maximum drawing ratio at 200℃ reached 1.2 times of that at room temperature, and the drawing depth without fracture reached 1.8 times. The higher temperature was adopted, the more stable and uniform thickness strain distribution was observed.The limiting drawing ratio(LDR) under uniform beating of blanks was measured at the various temperature ranges between 25℃ and 250℃ by using two different blank shapes, square and circular blanks, and six different blank sizes with the drawing ratios(DR) of 2.4 to 2.7. The orgaric coated steel skeets(SCP3CJ-3K/3K) of 0.7mm thickness were used. The maximum drawing ratio at 200℃ reached 1.2 times of that at room temperature, and the drawing depth without fracture reached 1.8 times. The higher temperature was adopted, the more stable and uniform thickness strain distribution was observed.

증기발생기 세관에서 결함 선단 변화에 따른 와전류 결함신호의 분석

송성진,김의래,김창환,김영환 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

Eddy current signals from flaws with tip variation in steam generator tubes were analyzed. Using finite element models, abundant flaw signals from two dimensional axisymmetric flaws will tip variation were generated. Features of ECT signal were defined and extracted, and sensitive features for flaw classification and sifting were selected. Two neural networks were employed for flaw characterization and sizing. The intercept vector was introduced as a new feature, and its usefulness was discussed.

지능형 알고리즘을 이용한 엘리베이터 안전진단 및 분석 포터블 장비 개발

김태형,김훈모 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

An elevator system, which is essential equipment for vertical movement of an object, as a property of building, has been driven by various expenditures and purposes. Since developing electrical control technology, control systems are highly developed. The elevator system has expanded widely. but a data accuracy acquisition technique and safety predict technique for securing system safety is still at a basic level. So, objective verification for elevator confidence condition requires an absolute accuracy measurement technique. Therefore, this study is executed in order to acquire a method of depending on sense of a manager with simple numeric measurement data, and to construct a logical, analytical foresight system for more efficient elevator management system. As an artificial intelligence for diagnosis, the fuzzy inference algorithm is used for foreseeing the system in this thesis, because the fuzzy algonthm is the most useful method for resolving subjective ideas and a vague judgment of humans. The fuzzy inference algorithm is developed for earth sensor signal (i.e vibration, velocity, current).

구형 스크린을 이용한 준몰입형 VR 시스템 개발

서명원,박대유,조기용 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

The virtual reality technology has been developed as the computer and computer graphic technology are progressed. However it has stall the limits of the use because of it costs a great for system construction. A virtual reality technology is the best application example to reduce time and coat of development in engineering. Actually, VR(Virtual reality) technology has given engineers the ability to design, test and evaluate engineering systems in a virtual environment. The objective of this paper is to construct the arm mounted display VR system by using 3 channel spherical screen and to show its capabilities of an engineering system development. This paper describes the development of arm mounted display VR system with 3 channel spherical screen system and the generation of 3 channel graphic modules. The arm mounted display VR system provides a highly economial efficiency because of it uses a popular computer system as a graphic server.

자유유동 난류강도 변화가 가스터빈 회전익 열전달 특성에 미치는 영향

구경하,김윤제 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

The characteristics of heat transfer and boundary layer flow on the SSME turbine blade are investigated with LRN k- ε turbulence model. The relevant governing equations are discretized to a system of finite different equations by means of a BTBCS implicit method. These equationss have been solved for the velocity and temperature fields using tridiagonal matrix algorithm. Stanton number and heat flux on the blade surface are calculated with various turbulence intensities. Numerical results are compared with the existing experimental data. Results show that the higher free-stream turbulence intensity promotes earlier boundary layer transition and causes much higher heat transfer rate on the suction surface.

소형보행로봇의 이동방법에 관한 연구

박재준, 김동주, 최혁렬 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

This paper describes the locomotion method of Walking robots by introducing two robots, a biped walking robot and a quadraped walking robot, whnch we have manufactured. The biped robot made of LEGO MINDSTORM has bean destined to have the minimal number of actuator. It presents a locomotion method in which robots can walk with a few actuators. The Quadraped Walking robot has three dgree of freedom per a leg, and use RC Servo motor as actuator. we researched walking pattern of quadrated walking robot through this robot. In this paper we also discuss the problems of developing walking robots and solutions.

P92강의 고온피로특성

원성준,정찬서,임병수 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

In this paper, fatigue characteristics of P92 steel at high temperature are investigated to obtain basic mechanical properties and to study effect of temperature on fatigue crack growth behavior in P92 steel. Both tensile test and fatigue crack growth test were cared out at 55O℃, 600℃ and 650℃. From the tensile tests, yield strengths, tensile strengths, reduction rates in area and elongations were obtained. From the fatigue crack growth tests, fatigue crack growth rates were calculated at each test temperature and they were compared with each other to study the effect of temperature on fatigue crack growth rate.

확률론적 파괴역학을 도입한 원전배관의 건전성평가 기법에 관한 연구

곽상록,이준성,김영진 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

For nuclear piping periodic inspections and integrity assessments are needed for the safety. But many flaws are undetectable due to sampling inspection. Probabilistic integrity assessment is applied to take into consideration of uncertainty and variance of input parameters arise due to material properties, applied load and undetectable flaws. This paper describes a Probabilistic Fracture Mechanics(PFM) analysis based on Monte Carlo(MC) algorithms. Taking important parameters at probabilistic variables such as fracture toughness, crack growth rate and flaw shape, failure probability of nuclear piping is archived as a results of MC simulation. Fer the verification of analysis results, a comparison study of the PFM analysis using other commercial code, mathematical method is carried out and a good agreement was observed between those results.

다단 원판형 드래그펌프의 배기특성에 관한 실험적 연구

황영규,허중식,권명근 성균관대학교 기계기술연구소 2001 성균관대학교 논문집 기계기술편 Vol.4 No.1

In this paper, the pumping performance of the multi-stage(two-stage) disk-type drag pump which works in the pressure range from 4 to 0.003 Torr was studied experimentally, and rotational speed of the pump is 24,000rpm and nitrogen is used as a test gas. An experimental study on pumping characteristics of various multi-stage disk-type drag pump is performance. The inlet pressures are measured for various outlet pressures of teat pump. The maximum compression ratios for nitrogen are 1000(multi-stage disk-type drag pump), 740(helical-type drag pump), 90(BSC disk-type drag pump) and 85(OSC disk-type drag pump), respectively. The ultimate pressure of the multi-stage disk-type drag pump is 3.7×10-5 Torr at 0.003 Torr for outlet pressure. The maximum value of compression ratio is 1000 at 0.6 Torr for outlet pressure.