• Title/Summary/Keyword: shear structure

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Orthotropic Theory for the Prediction of Mechanical Performance in Thermally Point-bonded Nonwovens

  • Kim, Han-Seong
    • Fibers and Polymers
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    • v.5 no.2
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    • pp.139-144
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    • 2004
  • The orthotropic theory is applied for the nonwoven fabrics that have a preferred orientation direction, the case if the structure is not isotropic. The polynomial regression analysis is employed to allow the attainment of more statistically meaningful information. A functional form based on the transformation rule is developed for the orthotropic approach. The predictions thus obtained are seen to be in excellent agreements with experimental data and the resulting compliances exhibit meaningful relationships for the processing conditions. The compatibility of the compliances from tensile and shear analyses has been explored prior to a practical application of the four compliances defining the in-plane strain-stress field.

Equivalent Continuum Model for the Single Wall Carbon Nanotube (Single Wall Carbon Nanotube의 등가 연속체 모델에 대한 연구)

  • 김병구;전흥재
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2003.04a
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    • pp.227-234
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    • 2003
  • In this study, an equivalent continuum model for single wall carbon nanotube is proposed. The model links interatomic potentials and atom structure of a materials to a constitutive model on the continuum level. The Young's modulus and shear modulus were predicted by the model. The predictions were in good agreement with the prior experimental results available in the literatures. Also, the strain energy of the carbon nanotube was predicted as a function of the radius of the carbon nanotube.

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Problems in Seismic Design of High-Rise RC Building Structures having Irregularity (비정형 고층 RC 건축물의 내진설계 시 문제점)

  • 이한선;고동우
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.125-132
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    • 2003
  • This paper clarifies the problems which structural engineers would have when the high-rise reinforced concrete building structures with vertical and plan irregularities are to be designed against earthquakes. The most important problems appear to be as follows: (1) ambiguity in defining the principal direction of the structure and the dynamic base shear, (2) the methodology how to account for the accidental eccentricity when the modal analysis should be conducted as required for the torsionally irregular structures, and (3) the choice of 100/30 and SRSS methods to take into account the effect of the critical direction of earthquake.

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Optimum Design of Base Isolators Using Bouc-Wen Model (Bouc-Wen 모델을 이용한 면진장치의 최적설계)

  • 문석준;정정훈;김병현
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2003.09a
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    • pp.395-402
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    • 2003
  • Characteristics of base isolators including frictional and hysteretic types may be described by Bouc-Wen model. A probabilistic optimum design method of the base isolation system using Bouc-Wen model is presented in this paper. For optimum design, the objective function and constraints are derived based on the stochastic responses of the system. As a numerical example, the optimum design problem of a three-story base isolated shear type structure is formulated and solved by the sequential quadratic programming method.

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Challenge in the Structural Design of Suzhou IFS

  • Zhou, Jianlong;Huang, Yongqiang
    • International Journal of High-Rise Buildings
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    • v.10 no.3
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    • pp.165-171
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    • 2021
  • Core-outrigger-mega frame system is used in Suzhou IFS with 95-story, 450 m-tall, which is beyond Chinese code limit. Besides simple introduction on design principle, structure system and analysis, key techniques including performance based design criteria, frame shear ratio, capacity check of mega column, human comfort criteria under wind induced vibration and TSD design were presented in details for reference of similar super tall building design.

Shear bond strength of rebonded ceramic brackets (세라믹 브라켓의 재접착이 전단 결합 강도에 미치는 영향)

  • Sung, Ji-Young;Kang, Kyung-Hwa
    • The korean journal of orthodontics
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    • v.39 no.4
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    • pp.234-247
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    • 2009
  • Objective: The purpose of this study was to evaluate the shear bond strength of rebonded ceramic brackets according to each condition and find an appropriate method to rebond ceramic brackets with proper shear bond strength in clinical practice. Methods: The study consisted of 12 experimental groups, according to the types of brackets, debonding methods, and treatment methods of the bracket base. Shear bond strength was measured, and adhesive residues left on the tooth surface were assessed. The base of the bracket was examined under scanning electron microscopy. Results: The shear bond strength of the monocrystalline ceramic bracket group was significantly higher than thatof the polycrystalline bracket group with only sandblasting (p < 0.05). There was no significant difference in shear bond strength between groups that used rebonded brackets which were debonded with shear force and debonded with laser (p > 0.05). The shear bond strength of the sandblasted/silane group was significantly higher than that of the selectively grinded group with a low-speed round bur and the sandblasted only group (p < 0.001). The retentive structure was more presented in groups where laser was applied than in groups where shear force was applied to debond brackets prior to rebonding. The bracket bases which were treated before rebonding presented smoother surfaces than new brackets. Conclusions: Shear bond strength could be increased by applying a silane coupling agent after sandblasting before rebonding. Also, the bond strength of the selectively grinded group with a low-speed round bur and the sandblasted group showed acceptable bond strength for clinical orthodontic treatment.

Safety Evaluation of Radiating Element by Structural Test and Stress Analysis (구조 실험 및 응력 해석을 통한 복사 소자의 안전성 평가)

  • Kim, Jin-Yul;Kim, Dong-Seob;Park, Byung-Rak;Kim, Jin-Sung;Kim, Min-Sung;Park, Chan-Yik;Hwang, Woon-Bong
    • Composites Research
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    • v.26 no.4
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    • pp.259-264
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    • 2013
  • This study manufactured the radiating element of multi-band antenna skin structure which satisfy electrical and mechanical performance and is made by double injection molding process. Structural test including impact and buckling test is carried out and stress analysis is simulated to evaluate safety of radiating element for the axial and shear loads, when changing of the skin structure is occurred by the external force. To predict allowable load of structure and evaluate safety on impact and buckling, experimental and analytic method is used in strength analysis of structure.

Noise and flow analysis of lift-type disk wind power System (양력형 디스크 풍력 발전기의 유동 및 소음 해석)

  • Ko, Seungchul;Na, Jisung;Lee, Joon Sang
    • Journal of the Korean Society of Visualization
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    • v.15 no.3
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    • pp.52-56
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    • 2017
  • In this study, we investigate the flow characteristics of lift-type disk which behaves the up-down motion using the large eddy simulation (LES) and immersed boundary method (IBM). Also, we perform the noise analysis using pressure field at 1.35 m distance and reveal the cause of noise to observe the vortical structure analysis of flow result. It is observed that vortical structure and wind shear were generated at leading edge and tower with high velocity deficit and flow separation. High magnitude of flow noise was observed in low frequency range which is from 30 Hz to 60 Hz. It was observed that vortical structure at leading edge was generated in frequency range from 33.3 Hz to 41.6 Hz. Temporal characteristic in vortical structure at leading edge was similar to noise characteristics, having the similar frequency ranges.