• 제목/요약/키워드: Manufacturing Assessment

검색결과 571건 처리시간 0.034초

RESEARCH OF WELDING EFFECT ON STRUCTURAL INTEGRITY AT HIGH TEMPERATURE

  • Tu, Shan-Tung;Yoon, Kee-Bong
    • 대한용접접합학회:학술대회논문집
    • /
    • 대한용접접합학회 1998년도 특별강연 및 추계학술발표 개요집
    • /
    • pp.11-24
    • /
    • 1998
  • The invention of fusion wilding technology has brought on a revolutionary change in manufacturing industry which enables the construction of large scale high temperature plants in chemical, petrochemical and power generation industries. However, among the failure cases of high temperature components, premature failures of weldments have taken a large percentage that indicates the detrimental effect of welding on structural integrity. The accurate prediction of the high temperature behaviour of welded components is thus becoming increasingly important in order to realise an optimised design and maintenance of a plant life. In the present paper, recent research activities on high temperature behaviour of welded structures are briefly summarised. A local deformation measuring technique is proposed to determine the creep properties of weldment constituents. A damage mechanics approach is introduced to study the life reduction and ductility reduction due to the presence of a weld in high temperature structures. Finally, the high temperature creep crack growth in weldments is discussed.

  • PDF

산업현장의 소음.진동 원인분석 및 저감방안 연구 (Assessment of Can Factory working noise and its reduction)

  • 전형준;고준희;장서일
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2006년도 추계학술대회논문집
    • /
    • pp.212-216
    • /
    • 2006
  • The purpose of this study is to obtain an effective enclosing method for noise reduction of press machine operating in a manufacturing company located in Korea. Noise level of the machine is about $90{\sim}105dB$ which is higher than legal standards by industrial safety and health law. This study has predicted the level of noise reduction according to a step by step prevention plan by considering the characteristics of the cause of noise, the permitted limit of noise levels, problems and economical efficiency attendant upon the noise prevention measures. The predicted level of noise at the plant in accordance with the first step is $71.5{\sim}89.5dB(A)$, and can satisfy the permitted limit of noise in a time period of the day. Based on these results, enclosing method adequate for the selected plant's noise characteristics were suggested.

  • PDF

엔드밀링에서 순간전단면을 이용한 절삭력 모델 연구 (A Study on the Instantaneous Shear Plane Based Cutting Force Model for End Milling)

  • Hong, Min-Sung
    • 한국공작기계학회논문집
    • /
    • 제11권4호
    • /
    • pp.34-43
    • /
    • 2002
  • The purpose of this paper is to further extend the theoretical understanding of the dynamic end milling process and to derive a computational model to predict the milling force components. A comparative assessment of different cutting force models is performed to demonstrate that the instantaneous shear plane based formulation is physically sound and offers the best agreement with experimental results. The procedure f3r the calculation of the model parameters used in the cutting force model, based on experimental data, has been presented. The validity of the proposed computational model has been experimentally verified through a series of cutting tests.

자동차용 금형제작의 CAD/DAM 시스템 및 요소기술 (A CAD/EAM System and Component Technology in Die Making for Automobile)

  • 한규택
    • 한국공작기계학회:학술대회논문집
    • /
    • 한국공작기계학회 1997년도 춘계학술대회 논문집
    • /
    • pp.119-124
    • /
    • 1997
  • This study investigates EAD/EAM system & component technology in die making for automobile, An assessment has been proceeded so that stamping car panel can be designed and manufactured efficiently. Also a method of measuring surface strains in a deformed three dimensional part has been analyzed which computes surface strains for the entire area under the view instead of determining surface strains from deformed circles one a time. For the technicians sutomated strain measurement system has the potential to become a powerful tool for successful press-die design and making. The obtained results will lead to the reductions in lead time and man-hour required for the design and manufacture of the stamping dies.

  • PDF

신뢰성공학에 근거한 하중-강도계수 설계법과 부분안전계수의 개념 및 적용 (The Concepts and the Applications of Load and Resistance Factor Design and Partial Safety Factor Based on the Reliability Engineering)

  • 유연식;김태완;김종인
    • 대한기계학회:학술대회논문집
    • /
    • 대한기계학회 2007년도 춘계학술대회A
    • /
    • pp.309-314
    • /
    • 2007
  • Recently, the LRFD and the PSF based on structural reliability assessment have been applied to NPP designs in behalf of the conventional deterministic design methods. In the risk-informed structural integrity, it is especially possible to optimize design procedures considering cost, manufacturing and maintenance because the structural reliability concepts have confirmed the reliability for which a designer aims. Generally, in order to evaluate the PSF, the LRFD which is the design concept for evaluating safety factors respectively on the limit state function including load and resistance. This study certifies the concept and its applications of the PSF using the LRFD based on the structural reliability engineering.

  • PDF

A Study on the Design of Gating System for Semi-Solid Diecasting Process

  • Park, Chul-Woo;Kim, Young-Ho
    • International Journal of Precision Engineering and Manufacturing
    • /
    • 제4권2호
    • /
    • pp.39-48
    • /
    • 2003
  • In the Semi-Solid Diecasters design, a Seni-Solid Diecasters experiment has usually been carried out before producing new casts. At the Semi-Solid Diecasting stages, the runner-gate part has been always repeatedly corrected, which leads to a tedious processing time and high processing cost. Much experience is essential in manual assessment and if the design is defective, much time and a great deal of efforts will be wasted in the modification of the die. In this study, a design system has been developed based on the design database In addition, a gate experiment for the gating system design has been tarried out to append the database. It is possible for engineers to make efficient gating system design of Semi-Solid Diecasting and it will result in the reduction of expenses and time to be required.

새로운 대기오염물질 배출원 분류체계에 관한 제언 (A Proposal on the New Air Emission Source Categories)

  • 홍지형;허정숙;이덕길;석광설;이대균;엄윤성
    • 한국대기환경학회지
    • /
    • 제18권3호
    • /
    • pp.231-245
    • /
    • 2002
  • A better knowledge of emission inventories can serve several important functions such as provision of public information, identification of primary sources, assessment of temporal and spatial trend, and analysis for national modelling studies. The purpose of this paper is to propose the new air emission source categories on the basis of the Korea Standard Industrial Classification. Hence, the paper focuses on reviewing and comparing the air emission sources categories of USEPA, and EU. The new emission source categories compose Tiers 1, 2, and 3. For Tier 1, there are 14 categories; fuel combustion-utilities, industries, and heating and others, chemical and allied product manufacturing, metals processing, and petroleum and related industries, etc. Tier 2 consists of small categories classified minutely in Tier 1. Tier 3 connects the categories of Tier 2 with the Korea Standard Industrial Classification.

Sensors, smart structures technology and steel structures

  • Liu, Shih-Chi
    • Smart Structures and Systems
    • /
    • 제4권5호
    • /
    • pp.517-530
    • /
    • 2008
  • This paper deals with civil infrastructures in general, sensor and smart structure technology, and smart steel structures in particular. Smart structures technology, an integrated engineering field comprising sensor technology, structural control, smart materials and structural health monitoring, could dramatically transform and revolutionize the design, construction and maintenance of civil engineering structures. The central core of this technology is sensor and sensor networks that provide the essential data input in real time for condition assessment and decision making. Sensors and robust monitoring algorithms that can reliably detect the occurrence, location, and severity of damages such as crack and corrosion in steel structures will lead to increased levels of safety for civil infrastructure, and may significantly cut maintenance or repair cost through early detection. The emphasis of this paper is on sensor technology with a potential use in steel structures.

ECONOMIC DESIGN OF SCREENING PORCEDURES CONSIDERING INSPECTION ERRORS

  • Kim, Young-Jin
    • 한국경영과학회:학술대회논문집
    • /
    • 한국경영과학회 2006년도 추계학술대회
    • /
    • pp.365-368
    • /
    • 2006
  • The implementation of a screening procedure for removing non-conforming products has become a common practice especially in high-tech manufacturing industries. Screening procedures involve a measurement on the quality characteristic of interest since decisions regarding the conformance to specifications are usually made on the basis of the realization of measurement. A significant variability in measurement procedures may result in the misclassification of an outgoing product (that is, falsely accepting defectives or falsely rejecting conforming items), which may lead to wrong interpretation on product quality, It may thus be necessary to consider the impacts of misclassification errors due to measurement variability when designing screening procedures. Along this line, this article investigates the design of screening procedures based on the assessment of misclassification errors. The main objective is to determine the screening limits on measured values so that two types of misclassification errors may properly be compromised.

  • PDF

Safety, High Quality, Confidence of Kaneka CoQ10

  • Fujii, Kenji
    • 한국약용작물학회:학술대회논문집
    • /
    • 한국약용작물학회 2006년도 Proceedings of The Convention of The Korean Society of Applied Pharmacology
    • /
    • pp.139-145
    • /
    • 2006
  • Kaneka Corporation (Kaneka) has been manufacturing CoQ10 under GMP regulation since 1977. Kaneka has a sophisticated quality control system and has been supplying high quality CoQ10 materials to the worldwide customers (Kaneka CoQ10) for about 30 years. Kaneka CoQ10 is characterized by a lot of safety data, which are derived from clinical trials with healthy volunteers (single-dose and 4-week multi-dose safety studies), animal studies (13-week sub-chronic study in dogs and 52-week chronic study in rats), three types of mutagenicity test, six type of skin irritation test (for cosmetics), and others. The risk assessment of CoQ10 was performed by Council for Responsible Nutrition (USA). They reviewed many of available clinical data including clinical trials using Kaneka Q10, and concluded that the upper level for supplements (ULS) of CoQ10 is 1,200mg/day (Hathcock and Shao. 2006, Regulatory Toxicology and Pharmacology, $\underline{45}$, 282 - 288).

  • PDF