• Title/Summary/Keyword: Design-time history

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Seismic Behavior and Recentering Capability Evaluation of Concentrically Braced Frame Structures using Superelastic Shape Alloy Active Control Bracing System (초탄성 형상기억합금 능동제어 가새시스템을 이용한 중심가새프레임 구조물의 지진거동 및 복원성능 평가)

  • Hu, Jong Wan;Rhee, Doo Jae;Joe, Yang Hee
    • Journal of the Earthquake Engineering Society of Korea
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    • v.16 no.6
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    • pp.1-12
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    • 2012
  • The researches related to active control systems utilizing superelastic shape memory alloys (SMA) have been recently conducted to reduce critical damage due to lateral deformation after severe earthquakes. Although Superelastic SMAs undergo considerable inelastic deformation, they can return to original conditions without heat treatment only after stress removal. We can expect the mitigation of residual deformation owing to inherent recentering characteristics when these smart materials are installed at the part where large deformation is likely to occur. Therefore, the primary purpose of this research is to develop concentrically braced frames (CBFs) with superelastic SMA bracing systems and to evaluate the seismic performance of such frame structures. In order to investigate the inter-story drift response of CBF structures, 3- and 6-story buildings were design according to current design specifications, and then nonlinear time-history analyses were performed on numerical 2D frame models. Based on the numerical analysis results, it can be comparatively verified that the CBFs with superelastic SMA bracing systems have more structural advantages in terms of energy dissipation and recentering behavior than those with conventional steel bracing systems.

A Study on Non-representation Approach Indicated in Paintings and Architecture - Focus on Francis Bacon's paintings and SANAA's Architectural projects - (회화와 건축에서 나타나는 비재현적 접근방법에 관한 연구 - 프란시스 베이컨의 회화와 SANAA의 건축 프로젝트를 중심으로 -)

  • Park, So-La;Lee, Young-Su
    • Korean Institute of Interior Design Journal
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    • v.21 no.5
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    • pp.114-121
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    • 2012
  • Gilles Deleuze is a philosopher who replaces the world of representation defined as supremacy of identity with the contemporary reason of non-representation in the history of western philosophy that wants to transcend Plato. Deleuze developed his own philosophical concept through philosophical reason and encounter with arts, for which reason he exerted a great influence on artists and architects in diverse fields. Particularly, 'Logic of Sensation' published in 1981 considers the non-representation painting approach through Francis Bacon's painting theory defined as 'invisible force's visibility'. And it is considered that SANAA's architecture among many contemporary architects accepted the essence of Deleuze's philosophy and continuously reflects it on projects. Hence, objective of the present study is to consider how the non-representation constituting a root for Deleuze's reason has been indicated in paintings and architecture through examining the works by Bacon and SANAA. First, a theoretical consideration will be directed to non-representation, followed by an analysis of Bacon's painting works and SANAA's architecture projects from the viewpoints of the force of isolation, the force of transformation, the force of dissipation and the force of time dealt with by Deleuze in 'Logic of Sensation'. Finally, through such analysis, the characteristics of Deleuze's non-representation indicated in architecture and paintings will be derived.

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A Study of Fashion Art Illustration

  • Kang, Hee-Myung;Kim, Hye-Kyung
    • Journal of Fashion Business
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    • v.6 no.3
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    • pp.94-109
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    • 2002
  • The advent of the information age, advancement of the multi-media, and proliferation of internet are all ushering-in a new era of a cyber world. The artistic expression is unfolding into a new genre of a new era.. In the modern art, the boundary between the fine art and the applied art is becoming blurred, and further, distinction of fine art from popular art is also becoming meaningless. The advancement of science and technology, by offering new materials and visual forms, is contributing to the expansion of the morden art's horizon. As fashion illustration is gaining recognition as a form of art which mirrors today's realities, it has also become increasingly necessary to add variety and newness. Fashion illustration is thus becoming the visual language of the modern world, capable of conveying artistic emotion, and at the same time able to effectively communicate the image of fashion to the masses. The increasing awareness of artistic talent and ingenuity as essential components of fashion illustration is yielding greater fusion between fashion illustration and art & technology. This has resulted in the use of the advanced computer technology as a tool for crafting artistic expressions, such as fashion illustration, and this new tool has opened-up new possibilities for expressing images and colors. Further, the computer-aided fashion illustration is emerging as a new technique for expression. The concept of fashion illustration, history of fashion illustration from its incepton to modern date is reviewed and the simplicity has been researched throughout past studies published in Korean and overseas Journals.

The length of plastic hinge area in the flanged reinforced concrete shear walls subjected to earthquake ground motions

  • Bafti, Farzad Ghaderi;Mortezaei, Alireza;Kheyroddin, Ali
    • Structural Engineering and Mechanics
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    • v.69 no.6
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    • pp.651-665
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    • 2019
  • Past earthquakes have shown that appropriately designed and detailed buildings with shear walls have great performance such a way that a considerable portion of inelastic energy dissipation occurs in these structural elements. A plastic hinge is fundamentally an energy diminishing means which decrease seismic input energy through the inelastic deformation. Plastic hinge development in a RC shear wall in the areas which have plastic behavior depends on the ground motions characteristics as well as shear wall details. One of the most generally used forms of structural walls is flanged RC wall. Because of the flanges, these types of shear walls have large in-plane and out-of-plane stiffness and develop high shear stresses. Hence, the purpose of this paper is to evaluate the main characteristics of these structural components and provide a more comprehensive expression of plastic hinge length in the application of performance-based seismic design method and promote the development of seismic design codes for shear walls. In this regard, the effects of axial load level, wall height, wall web and flange length, as well as various features of earthquakes, are examined numerically by finite element methods and the outcomes are compared with consistent experimental data. Based on the results, a new expression is developed which can be utilized to determine the length of plastic hinge area in the flanged RC shear walls.

Evaluation of Seismic Design Force by Earthquake Response Analysis of Water Tanks Installed in RC Buildings (건축물에 설치된 물탱크의 지진응답해석을 통한 설계하중 평가)

  • Baek, Eun Rim;Oh, Ji Hyeon;Choi, Hyoung Suk;Lee, Sang Ho
    • Journal of the Earthquake Engineering Society of Korea
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    • v.23 no.4
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    • pp.221-229
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    • 2019
  • Several water tanks installed in the building were damaged during the Gyeongju earthquake (2016) and the Pohang earthquake (2017). Since a water tank for fire protection is very important component, seismic safety should be ensured. In this study, an interaction between a water tank and a building was studied by the dynamic analysis of the RC building with the water tank. In case the water tank was installed on the roof of the RC building, it was confirmed that it did not significantly affect the response of the building. Based on the result, dynamic response characteristics of the water tank in the building were studied using two SDOF models represented dynamic behavior of the water tanks under earthquake. An earthquake time-history analysis was carried out with variables of aspect ratio of the tank, story of the building, and installed location in the building using three kinds of earthquakes.

The critical angle of seismic incidence of transmission tower-line system based on wavelet energy method

  • Tian, Li;Dong, Xu;Pan, Haiyang;He, Xiaoyu
    • Earthquakes and Structures
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    • v.17 no.4
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    • pp.387-398
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    • 2019
  • On the basis that ground motions may arrive at a structure from any horizontal direction and that different directions of seismic incidence would result in different structural dynamic responses, this paper focuses on orienting the crucial seismic incidence of transmission tower-line systems based on the wavelet energy method. A typical transmission tower-line system is chosen as the case study, and two finite element (FE) models are established in ABAQUS, with and without consideration of the interaction between the transmission towers and the transmission lines. The mode combination frequency is defined by considering the influence of the higher-order modes of the structure. Subsequently, wavelet transformation is performed to obtain the total effective energy input and the effective energy input rate corresponding to the mode combination frequency to further judge the critical angle of seismic incidence by comparing these two performance indexes under different seismic incidence angles. To validate this approach, finite element history analysis (FEHA) is imposed on both FE models to generate comparative data, and good agreement is found. The results demonstrate that the wavelet energy method can forecast the critical angle of seismic incidence of a transmission tower-line system with adequate accuracy, avoiding time-consuming and cumbersome computer analysis. The proposed approach can be used in future seismic design of transmission tower-line systems.

Seismic control of concrete buildings with nonlinear behavior, considering soil structure interaction using AMD and TMD

  • Mortezaie, Hamid;Zamanian, Reza
    • Structural Engineering and Mechanics
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    • v.77 no.6
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    • pp.721-734
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    • 2021
  • The seismic analysis of structures without applying the effects of soil can undermine functional objectives of structure so that it can affect all the desired purposes at the design and control stages of the structure. In this research, employing OpenSees and MATLAB software simultaneously and developing a definite three-dimensional finite element model of a high-rise concrete structure, designed using performance-based plastic design approach, the performance of Tuned Mass Damper (TMD) and Active Mass Damper (AMD) is both examined and compared. Moreover some less noted aspects such as nonlinear interaction of soil and structure, uplift, nonlinear behavior of structure and structural torsion have received more attention. For this purpose, the analysis of time history on the structural model has been performed under 22 far-field accelerogram records. Examining a full range of all structural seismic responses, including lateral displacement, acceleration, inter-story drift, lost plastic energy, number of plastic hinges, story shear force and uplift. The results indicate that TMD performs better than AMD except for lateral displacement and inter-story drift to control other structural responses. Because on the one hand, nonlinear structural parameters and soil-structure interaction have been added and on the other hand, the restriction on the control force applied that leads up to saturation phenomenon in the active control system affect the performance of AMD. Moreover, the control force applied by structural control system has created undesirable acceleration and shear force in the structure.

Factor analysis of subgrade spring stiffness of circular tunnel

  • Xiangyu Guo;Liangjie Wang;Jun Wang;Junji An
    • Earthquakes and Structures
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    • v.26 no.3
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    • pp.229-237
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    • 2024
  • This paper studied the subgrade spring stiffness and its influencing factors in the seismic deformation method of circular tunnel. Numerical calculations are performed for 3 influencing factors: stratum stiffness, tunnel diameter and burial depth. The results show that the stratum stiffness and tunnel diameter have great influence on the subgrade spring stiffness. The subgrade spring stiffness increases linearly with stratum stiffness increasement, and decreases with the tunnel diameter increasement. When the burial depth ratio (burial depth/tunnel diameter) exceeds to 5, the subgrade spring stiffness has little sensitivity to the burial depth. Then, a proposed formula of subgrade spring stiffness for the seismic deformation method of circular tunnel is proposed. Meanwhile, the internal force results of the seismic deformation method are larger than that of the dynamic time history method, but the internal force distributions of the two methods are consistent, that is, the structure exhibits elliptical deformation with the largest internal force at the conjugate 45° position of the circular tunnel. Therefore, the seismic deformation method based on the proposed formula can effectively reflect the deformation and internal force characteristics of the tunnel and has good applicability in engineering practice.

Application of the Taguchi Method to the Analysis of the Numerical Parameters Influencing Springback Characteristics (스프링백 특성에 영향을 미치는 수치변수의 분석을 위한 다구치 실험계획법의 응용)

  • Kim, Hyung-Jong;Jeon, Tae-Bo
    • Journal of Industrial Technology
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    • v.20 no.A
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    • pp.211-218
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    • 2000
  • It is desirable but difficult to predict springback quantitatively and accurately for successful tool and process design in sheet stamping operations. The result of springback analysis by the finite element method (FEM) is sensitively influenced by numerical factors such as blank element size, number of integration points, punch velocity, contact algorithm, etc. In the present work, a parametric study by Taguchi method is performed in order to evaluate the influence of numerical factors on the result of springback analysis quantitatively and to obtain the combination of numerical factors which gives the best approximation to experimental data. Since springback is determined by the residual stress after forming process, it is important to evaluate stress distribution accurately. The oscillation in the time history curve of stress obtained by the dynamic-explicit finite element method says that the stress solution at termination time is in very unstable state. Therefore, a variability study is also carried out in this study in order to assess the stability of implicit springback analysis starting from the stress solution by explicit forming simulation. The U-draw bending process, one of the NUMISHEET '93 benchmark problems, is adopted as an application model because it is most popular one for evaluating the springback characteristic.

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Detailed Finite Element Analysis of Full-scale Four-story Steel Frame Structure subjected to Consecutive Ground Motions

  • Tagawa, Hiroyuki;Miyamura, Tomoshi;Yamashita, Takuzo;Kohiyama, Masayuki;Ohsaki, Makoto
    • International Journal of High-Rise Buildings
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    • v.4 no.1
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    • pp.65-73
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    • 2015
  • Detailed finite element (FE) analyses of a full-scale four-story steel frame structure, subjected to consecutive 60% and 100% excitations from the JR Takatori records during the 1995 Hyogoken-Nanbu earthquake, are conducted using E-Simulator. The four-story frame was tested at the largest shake-table facility in the world, E-Defense, in 2007. E-Simulator is a parallel FE analysis software package developed to accurately simulate structural behavior up to collapse by using a fine mesh of solid elements. To reduce computational time in consecutive dynamic time history analyses, static analysis with gravity force is introduced to terminate the vibration of the structure during the analysis of 60% excitation. An overall sway mechanism when subjected to 60% excitation and a story mechanism resulting from local buckling of the first-story columns when subjected to 100% excitation are simulated by using E-Simulator. The story drift response to the consecutive 60% and 100% excitations is slightly smaller than that for the single 100% excitation.