• Title/Summary/Keyword: Element object

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Exterior Acoustic Holography Reconstruction of a Tuning Fork Using Inverse Non-singular BEM

  • Jarng, Soon-Suck
    • The Journal of the Acoustical Society of Korea
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    • v.22 no.1E
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    • pp.11-18
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    • 2003
  • Non-singular boundary element method (BEM) codes are developed in acoustics application. The BEM code is then used to calculate unknown boundary surface normal displacements and surface pressures from known exterior near field pressures. And then the calculated surface normal displacements and surface pressures are again applied to the BEM in forward in order to calculate reconstructed field pressures. The initial exterior near field pressures are very well agreed with the later reconstructed field pressures. Only the same number of boundary surface nodes (1178) are used for the initial exterior pressures which are at first calculated by Finite Element Method (FEM) and BEM. Pseudo-inverse technique is, used for the calculation of the unknown boundary surface normal displacements. The structural object is a tuning fork with 128.4 ㎐ resonant. The boundary element is a quadratic hexahedral element (eight nodes per element).

Exterior Acoustic Holography Reconstruction of a Tuning Fork using Inverse Non-singular BEM (역 비고유치 BEM을 사용한 소리 굽쇠의 외부 음향 홀로그래픽 재현)

  • Jarng, Soon-Suck;Lee, Je-Hyeong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.306-311
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    • 2002
  • Non-singular boundary element method (BEM) codes are developed in acoustics application. The BEM code is then used to calculate unknown boundary surface normal displacements and surface pressures from known exterior near Held pressures. And then the calculated surface normal displacements and surface pressures are again applied to the BEM in forward in order to calculate reconstructed field pressures. The initial exterior near field pressures are very well agreed with the later reconstructed field pressures. Only the same number of boundary surface nodes (1178) are used far the initial exterior pressures which are initially calculated by Finite Element Method (FEM) and BEM. Pseudo-inverse technique is used for the calculation of the unknown boundary surface normal displacements. The structural object is a tuning fork with 128.4 Hz resonant. The boundary element is a quadratic hexahedral element (eight nodes per element).

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Structure Analysis of Vehicle Air Compressor (자동차용 공기압축기의 구조해석)

  • 원종진;이종선;흥석주;이현곤
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.05a
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    • pp.45-50
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    • 1999
  • The object of this study is structure analysis of vehicle air compressor. Structure analysis is compose to nodal solution and element solution using ANSYS code. Then analysis is partition to head part, cylinder and piston part of vehicle air compressor. Stress and strain results are satisfy to Von Mises yield criterion.

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Damage Assessment of Free-fall Dropped Object on Sub-seabed in Offshore Operation

  • Won, Jonghwa;Kim, Youngho;Park, Jong-Sik;Kang, Hyo-dong;Joo, YoungSeok;Ryu, Mincheol
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.4
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    • pp.198-210
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    • 2015
  • This paper presents the damage assessment of a free-fall dropped object on the seabed. The damage to a dropped object totally depends on the relationship between the impact energy and the soil strength at the mudline. In this study, unexpected dropping scenarios were first assumed by varying the relevant range of the impact velocity, structure geometry at the moment of impact, and soil strength profile along the penetration depth. Theoretical damage assessments were then undertaken for a free-fall dropping event with a fixed final embedment depth for the structure. This paper also describes the results of a three-dimensional large deformation finite element analysis undertaken for the purpose of validation. The analyses were carried out using the coupled Eulerian-Lagrangian approach, modifying the simple elastic-perfectly plastic Tresca soil model. The validation exercises for each dropping scenario showed good agreement, and the present numerical approach was capable of predicting the behavior of a free-fall dropped object.

A Study on the Landmark Experience for Anchorage in Pusan port (부산항에 있어서 묘박을 위한 랜드마크 체험에 관한 연구)

  • 이동화;강영조
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.4
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    • pp.59-64
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    • 1999
  • This study is about gaining orientation through anchorage act of a group of ferryman. In addition, a point acquisition and character of landmark that is closely realated to a point acquisition would be clarified by studying the form of configuration of the earth and object which is used landmark for anchorage. There are 13 anchorage points in the north part of Pusan harbor. 12 anchorage points are used to anchor. A ferryman let a ship which is temporarily anchoring move safely and speedily at the anchorage point. At that time, he uses landmarks by a technique of Overlay View. Between landmarks and viewer would be formed exquisite location combination. A mountain peak, a peak of island, nature configuration of land such as intermitent rock and location, size and form of buildings or structures of a city were variously appeared as landscape elements which were used landmarks. Looking at conditions to be easily captured as a target object, 1. A particular point of a mountain ridge line which was not shield by buildings. 2. In case objects have similar form, the building which was located in the front or the highest. 3. In case of a singular object, whatever there is physical elements, that would be a target object. Through this study a configuration of the ground such as a mountain peak which is become the background of harbor landscape is very important element to find anchorage point in configuration of the ground and object. So, the continuous preservation of the contour line of mountain is needed to do safe and effective anchorage act.

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A Study on the Weight Lightening Algorithm of 3-Dimensional Large Object based on Spatial Data LOD (공간데이터 LOD 기반 3차원 대용량 객체의 경량화 알고리즘 연구)

  • Na, Joon Yeop;Hong, Chang Hee
    • Spatial Information Research
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    • v.21 no.6
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    • pp.1-9
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    • 2013
  • Recently, Construction information is being changed from CAD to BIM, and GIS is extending from outdoor to indoor information. In these circumstances, the needs of continuous use of construction information linked with GIS are growing constantly in stages of maintenance, operation and service as well as planning, design and construction. To this end, it is essential element to represent 3-dimensional large object efficiently in establishing BIM-GIS interoperability platform by combination of construction and spatial information. In this study, we design spatial data LOD for making spatial object and texture by level, and develop weight lightening algorithm of large spatial object.

A Study on the Design Concept and Simplified Analysis Method in Dropped Object Accidents by Lifting Crane (크레인 중량물 낙하사고에 대응한 설계개념과 간이 해석법에 대한 연구)

  • Kim, Ul-Nyeon;Kim, Han-Byul
    • Journal of the Society of Naval Architects of Korea
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    • v.56 no.3
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    • pp.251-262
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    • 2019
  • This paper is about design concept and simplified analysis method against dropped object events. The ships and offshore structures are exposed to various types of dropped object accidents such as laydown area struck by drill collar and topside deck hit by food container during their lifetime. Mitigation can be accomplished by proper facility layout and designing structures to safely absorb energy from accidental loads. It shall be designed to avoid loss of life, environmental pollution and loss of assets. Impact loads can lead to structural global collapse of the main structure or punching of a local barrier type structure with potential to escalate directly or indirectly to a global collapse of the structure. This study provides the background information on the issue of dropped object of the shipyard and also focuses on structural assessment of the local individual component such as deck plate, stiffener and web/girder by using simplified analysis method. The results of the simplified analysis method were compared with numerical results using non-linear finite element simulation.

A Study on Structural reinforcement suggestions for improvement of Seismic Performance of Masonry Buildings in rural areas (농촌지역의 조적조 건축물의 내진성능 개선을 위한 구조적 보강법 제안에 관한 연구)

  • Lee, Deog-Yong;Kim, Il-Jung
    • Journal of the Korean Institute of Rural Architecture
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    • v.15 no.4
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    • pp.51-58
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    • 2013
  • This study Masonry Buildings in rural areas, due to the lateral load resistance for seismic reinforcement method is proposed. Some of the proposed methods for reinforcement directly through finite element analysis to evaluate the change in frequency. The results for the following: This paper has the object of investigating natural frequencies of opening thick plates on Pasternak foundation by means of finite element method and providing Kinematic design data for mat of building structures. In this paper, vibration analysis of rectangular opening thick plate is done by use of Serendipity finite element with 8 nodes by considering shearing strain of plate. It is shown that natrural frequencies depend on not only Winkler foundation parameter but also shear foundation parameter, opening position.

Finite Element Analysis for Pearlite Transformation of Carbon Steel (탄소강의 펄라이트 변태에 대한 유한요소 해석)

  • 탄소강
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.9 no.3
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    • pp.69-75
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    • 2000
  • The object of the research is to estimate for pearlite structure of quenched carbon steels. The effects of temperature on physical properties metallic structures and the latent heat by phase transformation were considered. In this study a set of constitutive equations relevant to the analysis of thermo-elasto plastic materials with pearlite phase transformation during quenching process way presented on the basis of continuum thermo-dynamics. The iso-thermal transformation curve of the SM50C was formlated by cubic spline curve. The formulated equations of evolution in pearlite transformation was used for structure analysis. The volume fraction of pearlite was obtained from the results of calculated metallic structure by Finite element equation.

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Vibration Analysis of Tapered Thick Plate Subjected to Static In-plane Stress on Pasternak Foundation (Pasternak지반 위에 놓인 면내력을 받는 변단면 후판의 진동해석)

  • Cheong, Jin-Taek;Lee, Yong-Soo;Oh, Soog-Kyoung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.4 s.97
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    • pp.388-394
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    • 2005
  • This paper has the object of investigating natural frequencies of tapered thick plate on Pasternak foundation by means of finite element method and providing kinetic design data for mat of building structures. Vibration analysis for tapered thick plate subjected to in-plane stress is presented in this paper. Finite element analysis of rectangular plate is done by use of rectangular finite element with 8-nodes. Analysis conditions of tapered thick plate are as follows each. The ratio of in-plane stress to critical load is varied with $0.2\sigma_{cr}$, $0.4\sigma_{cr}$, $0.6\sigma_{cr}$. The Winkler parameter is 0, 10, 100, 1000, the shear foundation parameter is 0, 10 and the taper ratio is 0.0, 0.2, 0.4, 0.6, 0.8.