• Title/Summary/Keyword: new material model

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A Study on the Floating Building as a New Paradigm of Architecture (새로운 패러다임으로서의 플로팅 건축에 대한 연구)

  • Moon, Chang-Ho
    • Journal of Navigation and Port Research
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    • v.37 no.3
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    • pp.315-320
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    • 2013
  • According to climate change, deficiency of usable land, large water portion of the Earth surface, and improvement of income level, floating architecture is emerging as a strong & attractive alternative. The aim of this study is to suggest some related applying ways for new building projects around waterside. New paradigm of architecture can be described as a new model and/or system of architecture with new concept and Zeitgeist like sustainability and green building. Floating building is already a new paradigm of architecture comparing with the preconception of building only on the land and current building regulations. New paradigm features from the sample projects can be summarized as new concepts of building, application of various renewable energy resources(water, solar, wind), modular construction, use of local raw material, dual purpose usage, long term and relocatable usage, and special building materials for green building.

Adaptive location of repaired blade for multi-axis milling

  • Wu, Baohai;Wang, Jian;Zhang, Ying;Luo, Ming
    • Journal of Computational Design and Engineering
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    • v.2 no.4
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    • pp.261-267
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    • 2015
  • Free-form blades are widely used in different industries, such as aero-engine and steam turbine. Blades that are damaged during service or have production deficiencies are usually replaced with new ones. This leads to the waste of expensive material and is not sustainable. However, material and costs can be saved by repairing of locally damaged blades or blades with localized production deficiencies. The blade needs to be further machined after welding process to reach the aerodynamic performance requirements. This paper outlines an adaptive location approach of repaired blade for model reconstruction and NC machining. Firstly, a mathematical model is established to describe the localization problem under constraints. Secondly, by solving the mathematical model, localization of repaired blade for NC machining can be obtained. Furthermore, a more flexible method based on the proposed mathematical model and the continuity of the deformation process is developed to realize a better localization. Thirdly, by rebuilding the model of the repaired blade and extracting repair error, optimized tool paths for NC machining is generated adaptively for each individual part. Finally, three examples are given to validate the proposed method.

Estimation of Leak Rate Through Cracks in Bimaterial Pipes in Nuclear Power Plants

  • Park, Jai Hak;Lee, Jin Ho;Oh, Young-Jin
    • Nuclear Engineering and Technology
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    • v.48 no.5
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    • pp.1264-1272
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    • 2016
  • The accurate estimation of leak rate through cracks is crucial in applying the leak before break (LBB) concept to pipeline design in nuclear power plants. Because of its importance, several programs were developed based on the several proposed flow models, and used in nuclear power industries. As the flow models were developed for a homogeneous pipe material, however, some difficulties were encountered in estimating leak rates for bimaterial pipes. In this paper, a flow model is proposed to estimate leak rate in bimaterial pipes based on the modified Henry-Fauske flow model. In the new flow model, different crack morphology parameters can be considered in two parts of a flow path. In addition, based on the proposed flow model, a program was developed to estimate leak rate for a crack with linearly varying cross-sectional area. Using the program, leak rates were calculated for through-thickness cracks with constant or linearly varying cross-sectional areas in a bimaterial pipe. The leak rate results were then compared and discussed in comparison with the results for a homogeneous pipe. The effects of the crack morphology parameters and the variation in cross-sectional area on the leak rate were examined and discussed.

Static analysis of the FGM plate with porosities

  • Benferhat, R.;Hassaine Daouadji, T.;Hadji, L.;Said Mansour, M.
    • Steel and Composite Structures
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    • v.21 no.1
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    • pp.123-136
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    • 2016
  • This work focuses on the behavior of the static analysis of functionally graded plates materials (FGMs) with porosities that may possibly occur inside the functionally graded materials (FGMs) during their fabrication. For this purpose a new refined plate theory is used in this work, it contains only four unknowns, unlike five unknowns for other theories. This new model meets the nullity of the transverse shear stress at the upper and lower surfaces of the plate. The parabolic distribution of transverse shear stresses along the thickness of the plate is taken into account in this analysis; the material properties of the FGM plate vary a power law distribution in terms of volume fraction of the constituents. The rule of mixture is modified to describe and approximate material properties of the FG plates with porosity phases. The validity of this theory is studied by comparing some of the present results with other higher-order theories reported in the literature, the influence of material parameter, the volume fraction of porosity and the thickness ratio on the behavior mechanical P-FGM plate are represented by numerical examples.

Buckling behaviours of functionally graded polymeric thin-walled hemispherical shells

  • Uysal, Mine U.
    • Steel and Composite Structures
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    • v.21 no.4
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    • pp.849-862
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    • 2016
  • This paper investigates the static buckling behaviours of Functionally Gradient Polymeric Material (FGPM) shells in the form of hemispherical segment. A new FGPM model based on experimental was considered to investigate the buckling problem of thin-walled spherical shells loaded by the external pressure. The spherical shells were formed by FGPM which was produced adding the two types of graphite powders into epoxy resin. The graphite powders were added to the epoxy resin as volume of 3, 6, 9, and 12%. Halpin-Tsai and Paul models were used to determine the elastic moduli of the parts of FGPM. The detailed static buckling analyses were performed by using finite element method. The influences of the types and volume of graphite powders on the buckling behaviour of the FGPM structures were investigated. The buckling loads of hemispherical FGPM shells based on Halpin-Tsai and Paul models were compared with those determined from the analytical solution of non-graphite condition existing for homogeneous material model. The comparisons between these material models showed that Paul model was overestimated. Besides, the critical buckling loads were predicted. The higher critical buckling loads were estimated for the PV60/65 graphite powder due to the compatible of the PV60/65 graphite powder with resin.

Triple Material Surrounding Gate (TMSG) Nanoscale Tunnel FET-Analytical Modeling and Simulation

  • Vanitha, P.;Balamurugan, N.B.;Priya, G. Lakshmi
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.15 no.6
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    • pp.585-593
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    • 2015
  • In the nanoscale regime, many multigate devices are explored to reduce their size further and to enhance their performance. In this paper, design of a novel device called, Triple Material Surrounding Gate Tunnel Field effect transistor (TMSGTFET) has been developed and proposed. The advantages of surrounding gate and tunnel FET are combined to form a new structure. The gate material surrounding the device is replaced by three gate materials of different work functions in order to curb the short channel effects. A 2-D analytical modeling of the surface potential, lateral electric field, vertical electric field and drain current of the device is done, and the results are discussed. A step up potential profile is obtained which screens the drain potential, thus reducing the drain control over the channel. This results in appreciable diminishing of short channel effects and hot carrier effects. The proposed model also shows improved ON current. The excellent device characteristics predicted by the model are validated using TCAD simulation, thus ensuring the accuracy of our model.

Development of Dome-Type Cold Storage Facility Using 3-D CFD Simulation (3차원 CFD 시뮬레이션을 이용한 돔형 저온저장고 개발)

  • 양길모;고학균;홍지향
    • Journal of Biosystems Engineering
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    • v.28 no.1
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    • pp.35-44
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    • 2003
  • This study was conducted to develop proper model for cold storage facility that could of for uniform heat movement and air movement f3r green grocery and improve improper design of the existing container-type cold storage facility. For that reason, new model(dome-type) cold storage facility was developed using 3-D CFD(computational fluid dynamics) simulation. The size was 6m${\times}$6m${\times}$5m. Its size and configuration were same to simulation model. Unit cooler was designed to send cold air in 4 side ways. A dome-type cold storage facility showed uniform distributions of air temperature and velocity because cold air was forced to move down along the ceiling and the wall and then circulated to the unit cooler from the central part of the floor. Dome-type cold storage facility also showed by low wind velocity, below 1 m/s that could minimized cold damage and quality deterioration.

Implementation of 2.5D Mapping System for Fashion Design (패션디자인을 위한 2.5D맵핑 시스템의 구현)

  • Lee, Min-Kyu;Kim, Young-Un;Cho, Jun-Ei;Han, Sung-Kuk;Jung, Sung-Tae;Lee, Yong-Ju;Jung, Suck-Tae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • v.9 no.2
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    • pp.599-602
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    • 2005
  • This paper utilizing model picture of finished clothes in fashion design field various material (textile fabrics) doing Draping directly can invent new design, and do not produce direction sample or poetic theme width and confirm clothes work to simulation. Also, construct database about model and material image that can confirm Mapping result by real time. Development did the 2.5D Mapping system that used path extraction algorithm, warp algorithm, a lighting extraction and application algorithm in order to implement natural Draping of model picture and material image.

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Static analysis of rubber components with piezoelectric patches using nonlinear finite element

  • Manna, M.C.;Sheikh, A.H.;Bhattacharyya, R.
    • Smart Structures and Systems
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    • v.5 no.1
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    • pp.23-42
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    • 2009
  • In order to reduce vibration or to control shape of structures made of metal or composites, piezoelectric materials have been extensively used since their discovery in 1880's. A recent trend is also seen to apply piezoelectric materials to flexible structures made of rubber-like materials. In this paper a non-linear finite element model using updated Lagrangian (UL) approach has been developed for static analysis of rubber-elastic material with surface-bonded piezoelectric patches. A compressible stain energy function has been used for modeling the rubber as hyperelastic material. For formulation of the nonlinear finite element model a twenty-node brick element is used. Four degrees of freedom u, v and w and electrical potential ${\varphi}$ per node are considered as the field variables. PVDF (polyvinylidene fluoride) patches are applied as sensors/actuators or sensors and actuators. The present model has been applied to bimorph PVDF cantilever beam to validate the formulation. It is then applied to study the smart rubber components under different boundary and loading conditions. The results predicted by the present formulation are compared with the analytical solutions as well as the available published results. Some results are given as new ones as no published solutions available in the literatures to the best of the authors' knowledge.

Bending analysis of advanced composite plates using a new quasi 3D plate theory

  • Houari, Tarek;Bessaim, Aicha;Houari, Mohammed Sid Ahmed;Benguediab, Mohamed;Tounsi, Abdelouahed
    • Steel and Composite Structures
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    • v.26 no.5
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    • pp.557-572
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    • 2018
  • In this paper, a refined higher-order shear deformation theory including the stretching effect is developed for the analysis of bending analysis of the simply supported functionally graded (FG) sandwich plates resting on elastic foundation. This theory has only five unknowns, which is even less than the other shear and normal deformation theories. The theory presented is variationally consistent, without the shear correction factor. The present one has a new displacement field which introduces undetermined integral variables. Equations of motion are obtained by utilizing the Hamilton's principles and solved via Navier's procedure. The convergence and the validation of the proposed theoretical numerical model are performed to demonstrate the efficacy of the model.