잭업드릴링 리그는 해양 석유와 가스 탐사 산업에서 널리 사용되는 모바일 해양 플랫폼이다. 그것은 시추 및 생산을 위한 캔틸 레버 시추 장치가 있는 독립적인 3개의 다리가 있는 자체 승강식 장치이다. 전형적인 잭업리그는 삼각형 선체, 타워형 데릭, 캔틸레버, 잭 케이스, 거주구와 다리로 구성되며 여기에는 스퍼드캔 구조, 개방형 트러스, X-교차 구조로 구성된다. 일반적으로 잭업리그는 수심 130m~170m에서만 운용이 되고 있다. 최근 들어 개발 유정이 심해로 이동하면서, 깊은 수심과 가혹한 환경조건을 만족해야 한다. 리그의 작업 상태에서 모든 정적, 동적 하중은 레그(Leg)를 통해서 지탱되는 특징이 있다. 이러한 리그의 중요한 이슈는 순간적으로 큰 충격에너 지를 발생시키는 충돌에 대한 레그의 안전성이다. 본 연구에서는 LS-Dyna 프로그램을 이용하여 DNV 선급에서 규정하고 있는 충돌에너지 35MJ 요구사항에 대한 수치해석 및 검증을 수행하였다. 충돌 선박은 배수량 7,500톤 작업 지원선을 사용하였고, 5가지 충돌조건을 선정하 였다. 해석결과로부터 모든 충돌조건은 선급 기준을 만족하지 못한다. 코드 방향 충돌조건은 충돌에너지 15MJ, 브레이스 충돌조건은 6MJ 이 합리적이다. 따라서 충돌시나리오에 따른 합리적인 충돌에너지 기준의 제정이 필요로 하다.

This thesis relates to developing an index drilling automation system that quickly and efficiently processes a hole in a product by a rotating robot arm and transfer devices. Static structural analysis was performed using the ANSYS Mechanical program to evaluate the structural stability of the system. According to the research, the equivalent stress value is low overall, and the minimum safety factor is 4.42, so it seems structurally safe. This system will significantly help improve productivity through unmanned work as it can control and set the drill and index simultaneously on the control panel in conjunction with the training.

Ti₂AlN composites are a laminated compounds that posses unique combination of typical ceramic proper- ties and typical metallic(Ti alloy) properties. In this paper, the powder synthesis, SPS sintering, composite characteristics and machinability evaluation were systematically conducted. The random orientation characteristics and good crystalli- zation of the Ti2AlN phase are observed. The electrical and thermal conductivity of Ti2AlN is higher than that of Ti6242 alloy. A machining test was carried out to compare the effect of material properties on micro electrical discharge drilling for Ti2AlN composite and Ti6242 alloy. Also, mixture table as a kind of tables of orthogonal arrays was used to know how parameter is main effective at experimental design. Consequently, hybrid Ti2AlN ceramic composites showed good machining time and electrode wear shape under micro ED-drilling process. This conclusion proves the feasibility in the industrial applications.

When a new nuclear fuel is developed, irradiation test needs to be carried out in the research reactor to analyze the performance of the new nuclear fuel. It is necessary to attach sensors in the fuel rod and connect them with instrumentation cables to check the performance of the nuclear fuel during the burn up test in the test loop. A thermocouple is installed at the center of the fuel rod to check the centerline temperature of a fuel rod during the irradiation test. Therefore, A hole needs to be made at the center of a fuel pellet to put the thermocouple. However, it is difficult to make a small fine hole on the sintered UO2 pellet with a simple drilling machine, because the hardness and density of a sintered UO2 pellet are very high. In this study, an instrumented fuel rod mock-up was fabricated using an automated precise drilling machine. Four sintered alumina were drilled off and assembled into the zircaloy tube and a thermocouple was instrumented in the fuel rod mock-up. Sealing of an instrumented fuel rod mock-up was performed in the following two methods. It is sealing of similar metals perform by welding method, and sealing of dissimilar metals perform by swagelok method.