• Title, Summary, Keyword: ESO

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Synthesis of Epoxidized Soybean Oil (ESO) and its Blends with Tetrafunctional Epoxy Resins (Epoxidized soybean oil(ESO)의 합성 및 4 관능성 에폭시 수지/ESO 블렌드 시스템의 물성)

  • Lee, Jae-Rock;Jin, Fan-Long;Park, Soo-Jin
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.180-183
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    • 2003
  • In this work. a potential inexpensive epoxy resin. epoxidized soybean oil (ESO) was synthesized and applied as a toughening agent for 4.4'-tetradiglycidyl diaminodiphenyl methane (TGDDM). The chemical structure of ESO was characterized by FT-IR, $^1H NMR, and ^{13}C NMR$ spectroscopy. The curing behaviors. thermal stabilities. fracture toughness. and flexural strength of TGDDM/ESO blend systems were investigated by using the dynamic DSC. thermogravimetric analysis (TGA). and flexural tests. The thermal stabilities of TGDDM/ESO blend systems were decreased with increasing ESO contents. whereas the critical stress intensity factor ($K_{IC}$) and flexural strength ($\sigma_f$) were increased with ESO contents up to 10 wt% ESO.

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Shear Analysis of RC Structure using Evolutionary Structural Optimization (점진적 구조 최적화 기법을 이용한 철근 콘크리트 구조물의 전단 해석)

  • Kwak, Hyo-Gyoung;Yang, Kyu-Young;Shin, Dong-Kyu
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.24 no.3
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    • pp.319-328
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    • 2011
  • This paper introduces the construction of Strut-Tie model based on the Evolutionary Structural Optimization(ESO) method. Differently from conventional ESO method which uses plane stress elements, the introduced approach adopts the use of truss elements with the fact that the optimum topology of structures by ESO method is open a truss-like structure. Several examples are provided to demonstrate the capability of the proposed method in finding the best Strut-Tie models. In advance, it is shown that the introduced method is supported through the correlation studies between two-dimensional plane stress analysis and Strut-Tie models, and can be used effectively in practice, especially in shear design of complex reinforced concrete members where no previous experience is available.

New Bio-based Polymeric Materials from Plant Oils

  • Uyama, Hiroshi
    • Proceedings of the Polymer Society of Korea Conference
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    • pp.359-359
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    • 2006
  • This study deals with development of new bio-based polymeric materials from epoxidized soybean oil (ESO). The curing of ESO in the presence of organophilic montmorillonite produced an oil polymer-clay nanocomposite ("green nanocomposite") showing flexible property. A green nanocomposite (oil polymer-silica nanocomposite) coatings were synthesized by an acidcatalyzed curing of ESO with 3-glycidoxypropyltrimethoxysilane. The curing of ESO in the presence of a biodegradable plastic, poly(caprolactone), produced a composite with semi-IPN structure. The mechanical properties of the composite was much superior to those of polyESO. These new oil-based materials have large potential for applications in various fields.

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An Improved Element Removal Method for Evolutionary Structural Optimization

  • Han, Seog-Young
    • Journal of Mechanical Science and Technology
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    • v.14 no.9
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    • pp.913-919
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    • 2000
  • The purpose of this study was to develop a new element removal method for ESO (Evolutionary Structural Optimization), which is one of the topology optimization methods. ESO starts with the maximum allowable design space and the optimal topology emerges by a process of removal of lowly stressed elements. The element removal ratio of ESO is fixed throughout topology optimization at 1 or 2%. BESO (bidirectional ESO) starts with either the least number of elements connecting the loads to the supports, or an initial design domain that fits within the maximum allowable domain, and the optimal topology evolves by adding or subtracting elements. But the convergence rate of BESO is also very slow. In this paper, a new element removal method for ESO was developed for improvement of the convergence rate. Then it was applied to the same problems as those in papers published previously. From the results, it was verified that the convergence rate was significantly improved compared with ESO as well as BESO.

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A STUDY OF A TIDALLY INTERACTING BCD PAIR: ESO 435-IG20 AND ESO435-IG16

  • KIM, JINHYUB;SUNG, EON-CHANG;CHUNG, AEREE;STAVELEY-SMITH, LISTER
    • Publications of The Korean Astronomical Society
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    • v.30 no.2
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    • pp.513-515
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    • 2015
  • We investigate $H\small{I}$ data for a pair of blue compact dwarf galaxies (BCDs), ESO 435-IG20 and ESO 435-IG16, obtained with the Australia Telescope Compact Array. The outer $H\small{I}$ disk is highly disturbed and asymmetric in both galaxies showing a gas tail and/or a broad/extended gas disk on only one side. Based on their low-density surroundings and small projected distance (<80 kpc) at a similar redshift, we conclude that tidal interaction between these two BCDs is responsible for the morphological and kinematical peculiarities in $H\small{I}$. We also investigate their star formation rates using $H{\alpha}$ and UV imaging data to probe their interaction history.

Optimum Shape Design of a Rotating-Shaft Using ESO Method ESO 법을 이용한 회전축의 형상최적화

  • Yang, Bo-Suk;Kim, Yong-Han
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.360-364
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    • 2001
  • 본 논문에서는 최근의 진화적 구조최적화(ESO) 전략을 회전축의 형상최적화에 적용하였으며, 각 계산 스텝마다 단위 유한요소의 크기를 변경함으로써 기존의 방법보다 빠르고 정확한 최적형상에 수렴하는 새로운 방법을 제시하였다. 축요소의 직경을 시스템 설계변수로 하였으며, 축중량의 감소, 공진배율(Q-factor)의 감소 및 충분한 위험속도의 분리여유를 갖도록 목적함수를 설정하였다. 불평형응답 및 굽힙응력의 구속조건을 부가하였으며, 목적함수에 대한 설계변수의 감도해석을 수행하였다. 전동기축계에 대한 적용 결과로부터 주파수와 동적 구속조건하의 로터베어링 시스템에 대한 축 형상 최적화에 ESO법이 효과적으로 이용될 수 있음을 확인하였다.

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Determination of Strut-and-fie Models using Evolutionary Structural Optimization (ESO기법을 이용한 스트럿-타이 모델의 결정)

  • 곽효경;노상훈
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • pp.295-302
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    • 2002
  • This paper introduces a method to determine strut-tie models in reinforced concrete (RC) structures using the evolutionary structural optimization (ESO). Even though strut-tie models are broadly adapted in design of reinforced concrete members subjected to shear and torsion, conventional methods can hardly give correct models in RC members subjected to complex loadings and geometry conditions. In this paper, the basic idea of the ESO method is used to determine more rational strut-tie models. Since an optimum topology of structures, finally obtained by the ESO method, usually represents a truss-like structure, the ESO method can effectively be used in finding the best strut-tie model in RC structures. Several example structures are provided to demonstrate the capability of the proposed method in finding the best strut-tie model of each RC structure and to verify its efficiency in application to real design problems.

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A Study on the Reinforcement of Reinforced Concrete using Evolutionary Structural Optimization (점진적 구조 최적화 기법을 응용한 철근콘크리트 부재의 배근)

  • 윤성수;이정재
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.44 no.2
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    • pp.127-135
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    • 2002
  • Due to the fact that the design of a reinforced concrete structure changes in accordance with its shape and assigned load, total automation of the design system has not been achieved. For instance, since there is no general rule about setting up reinforcing steel quantity and arrangement location, it is simply not feasible to automatically decide the reinforcing arrangement location. In this study, the ESO(evolutionary structural optimization) technique and its related issues will be discussed. The ESO techniques is determined the reasonable load path which is traveling of load between in-flow and out-flow at a concrete structure using numerical analysis. And the results applied to the steel arrangement in reinforced concrete structures. The optimal algorithm, which determines the terminal criteria during ESO process, has been updated by using the obtained results. And the load path within the member has been determined automatically.

Comparative Study on Element Removal Methods for ESO (진화적 구조 최적화를 위한 요소 제거법의 비교 연구)

  • 한석영
    • Journal of The Korean Society of Manufacturing Technology Engineers
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    • v.9 no.5
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    • pp.112-118
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    • 2000
  • In case ESO(evolutionary structural optimization) which is one of topology optimization methods, the element removal ratio is fixed throughout topology optimization by 1 or 2%. As a result it has no flexibility for various types of structures and thus the rate of convergence might not be efficient. Thus various element removal methods were developed in order to improve the efficiency of ESO. In this paper, various element removal methods for ESO are compared with each other for a bracket and a short cantilever. In addition, a new improved bi-directional element removal method is suggested in order to obtain much better optimized topology. From the comparative results of the examples, it is verified that all of the developed various element removal methods are very effective, and the suggested element removal method is the most effective.

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