• Title/Summary/Keyword: Mock-up system

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Evaluation of Vibration and Structural Performance of an Innovative Sliding Step Steel Stair Using Full-Scale Mock-up Test (실물대 목업실험에 의한 슬라이딩스텝 철골계단의 진동 및 구조성능 평가)

  • Kim, Sung Yong;Lee, Cheol Ho;Kim, Na Eun;Cho, Sung Sang;Chung, Woon Ok
    • Journal of Korean Society of Steel Construction
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    • v.26 no.6
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    • pp.511-522
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    • 2014
  • In this study, an innovative steel stair system is presented which enables rapid erection and high quality control in both residential and office building construction. This system features two lightweight steel stringers of box shape, bolted connections easy to absorb construction tolerance, and stair steps movable transversely (or sliding steps) such that the work space needed for concrete stairway wall could be easily provided. In this type of stairway system, other than providing robust connecting details, ensuring vibration performance is especially important since this system may be vibration-sensitive due to lightweight nature and/or probable low damping. To tackle these issues, a series of full-scale mock-up tests were conducted by using box-shape stringer members with or without concrete-fill. The connection system was shown to be sufficiently stiff and strong, or it remained elastic even under the 160% of service load level. Among the seven stringer alternatives, five exhibited satisfactory vibration performance according to the related North American and European acceptance criteria.

A Study on the Application of Phased Array Ultrasonic Testing to Main Steam Line in Nuclear Power Plants (원전 주증기배관 웰더렛 용접부 위상배열초음파검사 적용연구)

  • Lee, Seung-Pyo;Kim, Jin-Hoi
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.7 no.3
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    • pp.40-47
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    • 2011
  • KSNPs(Korea Standard Nuclear Power Plant) have been applied the break exclusion criteria to the high energy lines passing through containment penetration area to ensure that piping failures would not cause the loss of containment isolation function, and to reduce the resulting dynamic effects. Systems with the criteria are the Main Steam system, Feed Water system, Steam Generator Blowdown system, and Chemical & Volume Control system. In accordance with FSAR(Final Safety Analysis Report), a 100% volumetric examination by augmented in-service inspection of all pipe welds appled the break exclusion criteria is required for the break exclusion application piping. However, it is difficult to fully satisfy the requirements of inspection because 12", 8" and 6" weldolet weldments of Main Steam pipe line have complex structural shapes. To resolve the difficulty on the application of conventional UT(Ultrasonic Testing) technique, realistic mock-ups and UT calibration blocks were made. Simulations of conventional UT were performed utilizing CIVA, a commercial NDE(Nondestructive Examination) simulation software. Phased array UT experiments were performed through mock-up including artificial notch type flaws. A phased array UT technique is finally developed to improve the reliability of ultrasonic test at main steam line pipe to 12", 8" and 6" branch connection weld.

Rotordynamic Characteristics of an APU Gas Turbine Rotor-Bearing System Having a Tie Shaft

  • Lee, An-Sung;Lee, Young-Seob
    • Journal of Mechanical Science and Technology
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    • v.15 no.2
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    • pp.152-159
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    • 2001
  • In this paper it is intended to set-up a sound model of the 60,000rpm 100kW prototype APU gas turbine rotor-bearing system, and particularly to investigate the influences of the tie shaft on the rotordynamic characteristics of the entire APU gas turbine rotor-bearing system, employing the dual shaft model. Firstly, a mock-up APU rotor has been constructed to test and verify the model. Analytical natural frequency results have agreed with the corresponding modal test ones to within 5% difference. Then, the rotordynamic characteristics of the prototype APU rotorbearing system have been investigated. Natural vibration and unbalance response analyses results have shown that the inner tie shaft resonance can cause high enough vibration of the outer main rotor shaft. This could be a concern as the rotor journals operate on very thin air film at high speed. It is concluded as a conservative design practice that the inner tie shaft should be explicitly modeled in the rotordynamic analysis of the APU rotor-bearing system.

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Design of Lightweight CAD Files with Dimensional Verification Capability for Web-Based Collaboration (웹기반 협업을 위한 치수검증이 가능한 경량캐드파일 설계)

  • Song In-Ho;Chung Sung-Chong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.30 no.5 s.248
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    • pp.488-495
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    • 2006
  • The demand for the use of 3D CAD data over the Internet environment has been increased. However, transmission of 3D CAD data has delayed the communication effectiveness because of the CAD data size. Lightweight CAD file design methodology is required for rapid transmission in the distributed environment. In this paper, to derive lightweight CAD files from commercial CAD systems, a file translation system producing a native file is constructed first by using the InterOp and API of the ACIS kernel. Using the B-rep model and mesh data extracted from the native file, the lightweight CAD file with topological information is constructed as a binary file. Since the lightweight CAD file retains topological information, it is applied to the dimensional verification, digital mock-ups and visualization of CAD files. Effectiveness of the proposed lightweight CAD file is confirmed through various case studies.

ASSESSMENT OF POSSIBILITY OF PRIMARY WATER STRESS CORROSION CRACKING OCCURRENCE BASED ON RESIDUAL STRESS ANALYSIS IN PRESSURIZER SAFETY NOZZLE OF NUCLEAR POWER PLANT

  • Lee, Kyoung-Soo;Kim, W.;Lee, Jeong-Geun
    • Nuclear Engineering and Technology
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    • v.44 no.3
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    • pp.343-354
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    • 2012
  • Primary water stress corrosion cracking (PWSCC) is a major safety concern in the nuclear power industry worldwide. PWSCC is known to initiate only in the condition in which sufficiently high tensile stress is applied to alloy 600 tube material or alloy 82/182 weld material in pressurized water reactor operating environments. However, it is still uncertain how much tensile stress is re-quired to generate PWSCC or what causes such high tensile stress. This study was performed to pre-dict the magnitude of weld residual stress and operating stress and compare it with previous experi-mental results for PWSCC initiation. For the study, a pressurizer safety nozzle was selected because it is reported to be vulnerable to PWSCC in overseas plants. The assessment was conducted by nu-merical analysis. Before performing stress analysis for plant conditions, a preliminary mock-up ana-lysis was done. The result of the preliminary analysis was validated by residual stress measurement in the mock-up. After verification of the analysis methodology, an analysis under plant conditions was conducted. The analysis results show that the stress level is not high enough to initiate PWSCC. If a plant is properly welded and operated, PWSCC is not likely to occur in the pressurizer safety nozzle.

Research of the Toolkit for easy and rapid prototyping (구동형 프로토타입의 쉽고 빠른 제작을 위한 인터랙티브 툴 킷 -상용 소프트웨어와 연동이 되는 모듈 형 하드웨어 툴 킷 개발을 중심으로-)

  • Jang, Sun-Yeon;Lim, Soo-Hyun;Hahn, Min-Soo
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.1020-1023
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    • 2009
  • It had been longer that the design mock-up was made mainly in order to test products. These days, it seems to be main stream that the working mockup is done because designers consider not only the design but also usability. In this study, the modular hardware toolkit, complimentary with Adobe Flash, was developed so that it solves the problem, the electronic hardware which the designers should struggle to make by themselves. This result thing could help the time of the design process to be short and contribute to make robust system rapidly.

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A Fundamental Study on Backfilling and Monitoring System for Stability of Underground Mine Openings (채굴공동의 안정성 유지를 위한 채움재의 충전과 계측시스템 구축에 관한 기초연구요)

  • Kim, Byung-Ryeol;Lee, Seung-Joong;Choi, Sung-Oong
    • Tunnel and Underground Space
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    • v.29 no.6
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    • pp.407-424
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    • 2019
  • To prevent possible accidents by surface subsidence, backfilling operation is known to be one of the most effective methods for ensuring the long-term ground stability because it can eliminate fundamentally the origin of underground mine opening collapse. Also, for effective backfilling of underground mine opening, it is necessary to keep monitoring of backfilled mine opening for analyzing several factors such as filling effect with change of backfill material and characteristics of backfill material. Therefore, in this study, a monitoring system which consists of measuring device and software program has developed to examine the performance of backfilling operation and verify to field applicability to underground mine. Sensors for measuring device have been selected through study of recent research papers and mock-up test has been performed to verify the system compliance. Also, monitoring result of the mock-up test compared to case studies in some countries. From monitoring result fo the mock-up test compared to case studies in some countries, consequently, it was concluded that the developed real-time monitoring system had ensured filed applicability in the underground mine.

Investigation of the Angular Distribution of Luminous Intensity in the Symmetric Optical System of a COB LED High Bay (COB LED High Bay 대칭형 광학계의 배광각에 관한 연구)

  • Yoo, Kyung-Sun;Lee, Chang-Soo;Hyun, Dong-Hoon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.23 no.6
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    • pp.609-617
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    • 2014
  • We have studied a chip-on-board LED lighting optical system for various luminous-intensity-distribution angles of the LED. An optical system that can accept different LEDs was made to reduce the systems's weight and size as we selected the chip-on-board LED, which is easy to apply to optical systems, unlike existing package-on-board LEDs. The luminous-intensity-distribution angles were $45^{\circ}$, $60^{\circ}$, $90^{\circ}$, and $120^{\circ}$. We researched these four types of optical systems. The $45^{\circ}$ and $60^{\circ}$ units were developed into reflectors, and the $90^{\circ}$ and $120^{\circ}$ units, into lenses. We checked the performance of the designed optical system through simulation and made a mock-up. Then we made a prototype of the chip-on-board LED high bay for use with the mock-up. After measuring its performance, we tested the luminous-intensity-distribution angles and compared them with simulation data. The resulting prototype was developed considering brightness, light uniformity, age, and economics which are suitable for a factory environment.

Assessment of Evaluation by Hybrid Waterproof-Roof Barrier Layer for Green System on Artificial Ground (인공지반 녹화시스템 활용을 위한 일체형 방수·방근 시트의 성능평가)

  • Oh, Chang-Won;Hong, Jong-Chul;Park, Ki-Bong
    • Journal of the Korea Institute of Building Construction
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    • v.15 no.4
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    • pp.391-396
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    • 2015
  • The demands about eco friendly space are increased as buildings are denser in downtown, and green system on the roof and the artificial ground are widely being applied. The construction of green system applies a waterproof layer, a root barrier and a protection concrete layer. Assembly of these many layers leads to a long construction term, and cause many defects. This study is to evaluate one layer-hybrid sheet which gets waterproof and root barrier performance simultaneously, which is developed to use in the new green system. As results, the performances of physical properties, durability, waterproof and root barrier not only exceeded quality standards but also showed excellent durability. In addition, mock-up test would be proceed to certify long term performance.

Development of Nondestructive System for Detecting the Cracks in KTX Brake Disk Using Rayleigh Wave (Rayleigh Wave를 이용한 KTX 제동 디스크의 균열 검측 시스템 개발)

  • Kim, Min Soo;Yeom, Yun Taek;Park, Jin-Hyun;Song, Sung Jing;Kim, Hak Joon;Kwon, Sung Duck;Lee, Ho Yong
    • Journal of the Korean Society for Nondestructive Testing
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    • v.37 no.1
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    • pp.29-36
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    • 2017
  • Recently, KTX (Korean Train Express) train stoppage accidents were mainly caused by malfunctioning equipment, aging and cracking of railway vehicles, crack breakages of brake disks, and breakages of brake disks. Breakage of brake disk can cause large-scale casualties such as high-speed collision and concern about derailment by hitting lower axle and wheel. Therefore, in this study, a brake disk with solid and ventilation type, which is the brake disk of a KTX train was modeled, and a dynamometer system was constructed to operate the disk. A Rayleigh wave was used to inspect the surface of the brake disk. An ultrasonic inspection module was developed for the brake disk by using a local immersion method due to the difficulty involved in ultrasonic inspection using an existing immersion method. In addition, the surface defects of the brake disk were evaluated using a dynamometer mock-up system and an ultrasonic inspection module of the brake disk.