• Title/Summary/Keyword: Structure integrity

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A Study on Manufacturing Technology and Evaluation of the Structural Integrity of a Sandwich Composite Train Roof Structure (샌드위치 복합재 철도차량 루프구조물의 구조 안전성 평가 및 제작기술 연구)

  • Shin Kwang-Bok;;;Lee Sang-Jin
    • Journal of the Korean Society for Railway
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    • v.9 no.1 s.32
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    • pp.43-49
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    • 2006
  • We have evaluated the structural integrity of a sandwich composite train roof structure that can be a lightweight, cost saving solution to large structural components for rail vehicles in design stages. The sandwich composite train roof structure was 11.45 meters long and 1.76 meters wide. The finite element analysis was used to calculate the stresses, deflections and natural frequencies of the sandwich composite train roof against the weight of air-conditioned system. The 3D sandwich finite element model was introduced to examine the structural behavior of the hollow aluminum extrusion frames joined to both sides of the sandwich composite train roof. The results shown that the structural performance of the sandwich composite train roof under loading conditions specified is satisfaction and the use of aluminum reinforced frame and aluminum honeycomb core is beneficial with regard to weight saving and structural performance in comparison with steel reinforced frame and polyurethane foam core. Also, we have manufactured prototype of sandwich composite train roof structure on the basis of analysis results.

A Study on the Turning System for Processing a Large Ship Propeller (대형 선박 프로펠러 가공 공정용 터닝 시스템에 관한 연구)

  • Do-Hun Chin
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.5
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    • pp.825-831
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    • 2023
  • The propellers used for big ships have a large diameter and are very heavy. In order to apply a precise and safe work process to them, it is necessary to use an exclusive turning system. For this reason, various techniques are applied to produce them. However, workers' convenience and safety are not taken into consideration enough at production sites. Conventionally, these propellers are designed to be separated as their turning system is loaded and rotated by empty weight. Therefore, it is necessary to replace such a design. This study tries to find the weaknesses of the design and structure of a conventional propeller turning system for large ships, to verify structure integrity of a structure in structural analysis, and to devise a plan for designing a new type of turning system. In the basic concept design and structural analysis for the turning system used in the propeller finishing process for large ships, this study drew the following conclusions. It was possible to develop the work process of the turning system for the propeller finishing process used for large ships, to obtain the dimensions for exterior design through a basic design. Structural analysis was conducted to find the structure integrity of the turning system. As a result, in the rail installed to transfer a gantry, the maximum stress was about 45MPa, about 5.5 times lower than the yield strength 250MPa. Therefore, the turning system was judged to be safe structurally.

Structural Joint Integrity Monitoring of Steel Frame Structures Using Impulse Responses (충격응답을 이용한 철골 구조물 접합부의 구조건전성 모니터링)

  • Yi, Jin-Hak;Lee, Kwang-Soo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2008.04a
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    • pp.145-150
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    • 2008
  • This study proposes an improved AR-model based structural joint integrity monitoring method and a new damage sensitive feature using RMS values of impulse responses. The proposed methods were applied for joint integrity monitoring of a model scale 2-bay and 4-story steel frame structure and it was found that the AR coefficients could be more consistently estimated by adopting the band-pass filter and cross-correlation function to the raw acceleration signals and the joint damages could be successfully monitored by the proposed methods.

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Evaluation of Structural Integrity for HANARO Capsule Structure by Vibration Test and Analysis (진동시험 및 해석을 통한 하나로 캡슐 구조물의 구조건전성 평가)

  • 이영신;강연환;최명환;신도섭
    • Journal of KSNVE
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    • v.10 no.2
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    • pp.261-268
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    • 2000
  • The instrumented capsule is subjected to flow-induced vibration(FIV) due to the flow of the primary coolant and then the structural integrity of the capsule during irradiation in the HANARO reactor is an issue of major concern. For this purpose the acceleration was measured by four accelerometers attached to the protection tube of the capsule mainbody and the displacement of test holes was calcultated using commercial finite element program ANSYS to evaluate the structural interference with the neighboring flow tubes under the reactor operating condition. The calculated displacements of test holes in the reactor in-core were found to be lower than the values of allowable design criteria.

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Development of Structural Analysis Modeling for KALIMER Fuel Rod

  • Kang, Hee-Young;Cheol Nam;Woan Hwang
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05b
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    • pp.175-180
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    • 1998
  • The U-Zr metallic alloy with low swelling HT9 cladding is the candidate for the KALIMER fuel rod. The fuel rod should be able to maintain the structural integrity during its lifetime in the reactor. In a typical metallic fuel rod, load is mainly applied by internal gas pressure, and the deformation is primarily caused by creep of the cladding. The three-dimensional FEM modelling of a fuel rod is important to predict the structural behavior in concept design stage. Using the ANSYS code, the 3-D structure analyses were performed for various configuration, element and loads. It has been shown that the present analysis model properly evaluate the structural integrity of fuel rod. The present analysis results show that the fuel rod is expected to maintain its structural integrity during normal operation.

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Evaluation of High Temperature Structural Integrity of Intermediate Heat Exchanger in a Steady State Condition for PGSFR (PGSFR중간열교환기의 정상상태 고온 구조 건전성 평가)

  • Lee, Seong-Hyeon;Koo, Gyeong-Hoi;Kim, Sung-Kyun
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.12 no.1
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    • pp.107-114
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    • 2016
  • Four cylindrically shaped IHXs(Intermediate Heat Exchangers) are installed in the PHTS(Primary Heat Transfer System) of the PGSFR(Prototype Gen IV Sodium cooled Fast Reactor). As for the IHX, the temperature difference of structure is inevitable result caused by heat transfer between primary coolant sodium and IHTS(Intermediate Heat Transport System) sodium. It is necessary to evaluate the high temperature structural integrity of IHXs which operate at the elevated temperature condition over the creep temperature. In this paper, the high temperature structural integrity of IHX under assumed loading conditions has been reviewed according to ASME code.

Modelling and integrity assessment of shear connectors in precast cast-in-situ concrete bridges

  • Moyo, Pilate;Sibanda, Bongani;Beushausen, Hans
    • Structural Engineering and Mechanics
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    • v.42 no.1
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    • pp.55-72
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    • 2012
  • Precast-cast insitu concrete bridge construction is widely practiced for small to medium span structures. These bridges consist of precast pre-stressed concrete beams of various cross-sections with a cast in-situ reinforced concrete slab. The connection between the beams and the slab is via shear links often included during the manufacturing process of the beams. This form of construction is attractive as it provides for standardisation, reduced formwork and construction time. The assessment of the integrity of shear connectors in existing bridges is a major challenge. A procedure for assessment of shear connectors based on vibration testing and finite element model updating is proposed. The technique is applied successfully to a scaled model bridge model and an existing bridge structure.

Interface between Morphology and Syntax: A Constraint-Based and Lexicalist Approach

  • Kim, Jong-Bok
    • Language and Information
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    • v.2 no.1
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    • pp.177-213
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    • 1998
  • conflicting criterial used in identifying words have called the lexical integrity principle into question. That is, cases where the morphological word does not coincide with the syntactic word have notivated the syntactic view of word derivation, as pointed out by Bresnan and Mchombo(1995). Further, the implicit desire to make the clausal structure of Korean parallel to those posited for English(Chomsky 1991) and French(Pollock 1989) has also led most of the current literature on Korean morphology to claim that Korean verbal inflections head their own functional projections such as AgrP, TP, and MP im syntax. In this paper, I will first argue against such a syntactic view. After reviewing some basic properties of Korean verbal inflections, I will show that the evidence from mismatch phenomena supports the lexical integrity principle over the head-movement theories of word derivation. Then, I will propose a theory of lexical grammar which maintains the lexical integrity principle while retaining the effects of functional projections and syntactic movement.

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A Study on Performance Improvements about Duct of Smoke Control System Combined with Air-Conditioning Equipment (공기조화설비 겸용 제연설비 덕트의 성능개선을 위한 연구)

  • Oh, Teakhum;Park, Chanseok
    • Journal of the Korea Safety Management & Science
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    • v.23 no.4
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    • pp.67-72
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    • 2021
  • To ensure the safety and functionality of a railroad bridge, maintaining the integrity of the bridge via continuous structural health monitoring is important. However, most structural integrity monitoring methods proposed to date are based on modal responses which require the extracting process and have limited availability. In this paper, the applicability of the existing damage identification method based on free-vibration reponses to time-domain deflection shapes due to moving train load is investigated. Since the proposed method directly utilizes the time-domain responses of the structure due to the moving vehicles, the extracting process for modal responses can be avoided, and the applicability of structural health evaluation can be enhanced. The feasibility of the presented method is verified via a numerical example of a simple plate girder bridge.