• 제목/요약/키워드: Structural behavior

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Fractal behavior identification for monitoring data of dam safety

  • Su, Huaizhi;Wen, Zhiping;Wang, Feng
    • Structural Engineering and Mechanics
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    • 제57권3호
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    • pp.529-541
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    • 2016
  • Under the interaction between dam body, dam foundation and external environment, the dam structural behavior presents the time-varying nonlinear characteristics. According to the prototypical observations, the correct identification on above nonlinear characteristics is very important for dam safety control. It is difficult to implement the description, analysis and diagnosis for dam structural behavior by use of any linear method. Based on the rescaled range analysis approach, the algorithm is proposed to identify and extract the fractal feature on observed dam structural behavior. The displacement behavior of one actual dam is taken as an example. The fractal long-range correlation for observed displacement behavior is analyzed and revealed. The feasibility and validity of the proposed method is verified. It is indicated that the mechanism evidence can be provided for the prediction and diagnosis of dam structural behavior by using the fractal identification method. The proposed approach has a high potential for other similar applications.

Structural redundancy of 3D RC frames under seismic excitations

  • Massumi, Ali;Mohammadi, Ramin
    • Structural Engineering and Mechanics
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    • 제59권1호
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    • pp.15-36
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    • 2016
  • The components of the seismic behavior factor of RC frames are expected to change as structural redundancy increases. Most researches indicate that increasing redundancy is desirable in response to stochastic events such as earthquake loading. The present paper investigated the effect of redundancy on a fixed plan for seismic behavior factor components and the nonlinear behavior of RC frames. The 3D RC moment resistant frames with equal lateral resistance were designed to examine the role of redundancy in earthquake-resistant design and to distinguish it from total overstrength capacity. The seismic behavior factor and dynamic behavior of structures under natural strong ground motions were numerically evaluated as the judging criteria for structural seismic behavior. The results indicate that increasing redundancy alone in a fixed plan cannot be defined as a criterion for improving the structural seismic behavior.

Structural behavior of cable-stayed bridges after cable failure

  • Kim, Seungjun;Kang, Young Jong
    • Structural Engineering and Mechanics
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    • 제59권6호
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    • pp.1095-1120
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    • 2016
  • This paper investigates the change of structural characteristics of steel cable-stayed bridges after cable failure. Cables, considered as the intermediate supports of cable-stayed bridges, can break or fail for several reasons, such as fire, direct vehicle clash accident, extreme weather conditions, and fatigue of cable or anchorage. Also, the replacement of cables can cause temporary disconnection. Because of the structural characteristics with various geometric nonlinearities of cable-stayed bridges, cable failure may cause significant change to the structural state and ultimate behavior. Until now, the characteristics of structural behavior after cable failure have rarely been studied. In this study, rational cable failure analysis is suggested to trace the new equilibrium with structural configuration after the cable failure. Also, the sequence of ultimate analysis for the structure that suffers cable failure is suggested, to study the change of ultimate behavior and load carrying capacity under specific live load conditions. Using these analysis methods, the statical behavior after individual cable failure is studied based on the change of structural configuration, and distribution of internal forces. Also, the change of the ultimate behavior and load carrying capacity under specific live load conditions is investigated, using the proposed analysis method. According to the study, significant change of the statical behavior and ultimate capacity occurs although just one cable fails.

수산해양계열 고등학생의 전공만족, 진로탐색 자기효능감 및 진로탐색행동의 구조적 관계 연구 (A Study on the Structural Equation Modeling of the Relationships among Major Satisfaction, Career Search Efficacy, and Career Exploration Behavior with Marine Science High School Students)

  • 허균
    • 수산해양교육연구
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    • 제25권6호
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    • pp.1306-1314
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    • 2013
  • The purpose of this study is to find the structural relationships among major satisfaction, career search efficacy, and career exploration behavior with marine science high school students. For investigating this topic, 524 students were surveyed from the marine science high schools. In order to find out the structural relationships among major satisfaction, career search efficacy, and career exploration behavior, structural equation modeling was used. Followings were the results of the research: (a) Major satisfaction effected significantly on the career search efficacy. (b) Career search efficacy effected significantly on the career exploration behavior. (C) There was not significant direct cause and effects from major satisfaction to career exploration behavior, but indirect effect was significant. Some recommendations were suggested for increasing career exploration behavior of marine science high school students.

단면 증설된 보-기둥 부재의 구조성능에 관한 실험적 연구 (An Experimental Studies on Structural Behavior of Reinforced Concrete Beam-Columns with Enlarged Cross Sections)

  • 신영수;홍기섭;최완철;박주현
    • 한국구조물진단유지관리공학회 논문집
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    • 제1권2호
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    • pp.141-149
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    • 1997
  • The major objects of this study is to investigate experimentally the strengthening effects and post-failure behavior of reinforced concrete beam-columns with enlarged sections. Tests are carried out to evaluate the influences of axial load intensities, thickness of encased steel plates and reinforcing bars in the grouted parts on the structural behavior of the specimens. The test results show that the amount of reinforcing bars and thickness of steel plate significantly affect on the structural behavior. The ultimate moment capacities of reinforced concrete beam-columns encased with 2mm-thick steel plate are significantly increased to about 10 times of those of unstrengthened specimens.

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AQWA-ANSYS 연계에 의한 대형 부유구조체의 파랑운동-구조거동 통합해석 (Integrated Analysis of Hydrodynamic Motions and Structural Behavior of Large-Scaled Floating Structures using AQWA-ANSYS Coupling)

  • 이두호;정연주
    • 한국전산구조공학회논문집
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    • 제24권6호
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    • pp.601-608
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    • 2011
  • 부유구조체의 설계를 위해서는 파랑하중하에서 부유구조체의 파랑운동 특성과 구조거동에 대한 평가가 요구된다. 부유구조체의 구조거동 평가에서는 파랑하중에 의한 파압분포가 반영되어야 하지만, hydrodynamic 해석모델과 구조해석 모델사이의 파압 연계가 어려워 정확한 구조거동 평가가 어려웠던 문제점이 있었다. 본 논문에서는 파랑하중하에서 대형 부유구조체의 정확한 구조거동 평가를 목적으로 파랑운동-구조거동 통합해석을 실시하였다. AQWA에 의한 hydrodynamic 해석을 바탕으로 부유구조체에 작용하는 파압 분포를 ANSYS Inc.에서 제공하는 Workbench 인터페이스를 이용하여 ANSYS의 구조해석 모델에 연계하였다. 연구결과 본 연구의 파랑운동-구조거동 통합해석은 파랑하중에 의해 부유구조체에 발생하는 파압분포를 구조해석 모델에 정확하게 반영할 수 있어 파랑하중에 의한 부유구조체의 구조거동을 정확하게 평가할 수 있는 것으로 나타났다. 또한, 상부 슬래브의 인장응력은 파랑 입사각 $0^{\circ}$의 경우에 가장 불리하고, 하부 슬래브의 인장응력은 파랑 입사각 $45^{\circ}$의 경우에 가장 불리한 것으로 나타났다.

Low-cycle fatigue evaluation for girth-welded pipes based on the structural strain method considering cyclic material behavior

  • Lee, Jin-Ho;Dong, Pingsha;Kim, Myung-Hyun
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.868-880
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    • 2020
  • One of the main concerns in the structural integrity of offshore pipelines is mechanical damage from external loads. Pipelines are exposed to fatigue failure in welded joints due to geometric discontinuity. In addition, fatigue loads such as currents, waves, and platform motions may cause significant plastic deformation and fracture or leakage within a relatively low-cycle regime. The 2007 ASME Div. 2 Code adopts the master S―N curve for the fatigue evaluation of welded joints based on the mesh-insensitive structural stress. An extension to the master S―N curve was introduced to evaluate the low-cycle fatigue strength. This structural strain method uses the tensile properties of the material. However, the monotonic tensile properties have limitations in describing the material behavior above the elastic range because most engineering materials exhibit hardening or softening behavior under cyclic loads. The goal of this study is to extend the cyclic stress-strain behavior to the structural strain method. To this end, structural strain-based procedure was established while considering the cyclic stress-strain behavior and compared to the structural strain method with monotonic tensile properties. Finally, the improved prediction method was validated using fatigue test data from full-scale girth-welded pipes.

Rebar corrosion effects on structural behavior of buildings

  • Yuksel, Isa
    • Structural Engineering and Mechanics
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    • 제54권6호
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    • pp.1111-1133
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    • 2015
  • Rebar corrosion in concrete is one of the main causes of reduction of service life of reinforced concrete buildings. This paper presents the influence of rebar corrosion on the structural behavior of reinforced concrete (RC) buildings subjected to strong earthquake ground motion. Different levels of rebar corrosion scenarios were applied on a typical four story RC frame. The deteriorated conditions as a result of these scenarios include loss in cross-sectional area and loss of mechanical properties of the reinforcement bars, loss in bond strength, and loss in concrete strength and its modulus of elasticity. Dynamic analyses of the frame with different corrosion scenarios are performed with selected strong earthquake ground motion records. The influences of degradation in both concrete and reinforcement on structural behavior are investigated by comparing the various parameters of the frame under different corrosion scenarios with respect to each other. The results show that the progressive deterioration of the frame due to rebar corrosion causes serious structural behavior changes such as change in failure mode. The intensity, propagation time, and extensity of rebar corrosion have very important effects on the level of degradation of steel and concrete, as well as on the earthquake behavior of the structure.

Structural behavior of the suspen-dome structures and the cable dome structures with sliding cable joints

  • Liu, Hongbo;Chen, Zhihua
    • Structural Engineering and Mechanics
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    • 제43권1호
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    • pp.53-70
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    • 2012
  • Sliding cable joints have been developed for the cable dome structures and the suspen-dome structures to reduce the cable pre-stressing loss and obtain a uniform inner force in each hoop cable. However, the relevant investigation is less addressed on the structural behavior of the cable dome structures and the suspen-dome structures with sliding cable joints due to the lack of analysis techniques. In this paper, a closed sliding polygonal cable element was established to analyze the structural behavior of the cable dome structures and the suspen-dome structures with sliding cable joints. The structural behaviors with sliding cable joints were obtained.

근속연수, 구조적 경력정체 및 대인 일탈행동간의 관계: 간호사를 대상으로 (The Relationship between Organizational Tenure, Structural Career Plateau, and Interpersonal Deviant Behavior: Focusing on Nurses)

  • 박오원
    • 아태비즈니스연구
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    • 제14권3호
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    • pp.103-114
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    • 2023
  • Purpose - The purpose of this study was to examine the relationship between organizational tenure, structural career plateau, and interpersonal deviant behavior for nurses. Moreover, this study also investigated moderating role of proactivity on the effect of organizational tenure on structural career plateau. Design/methodology/approach - This study utilized 448 nurses working at three different types of hospital. The Exploratory Factor Analysis (EFA) and the multiple regression analysis were conducted to verify the hypotheses. Findings - The results showed that organizational tenure is positively related to structural career plateau and structural career plateau is positively related to interpersonal deviant behavior. However, moderating effect of proactivity is not significant. Research implications or Originality - Nurses are critical to the competitiveness of hospital organizations considering the proportion of manpower and the role of nurses. One of the important factors that decrease the motivation of nurses is structural career plateau. This study analyzed the antecedent and consequence of structural career plateau. In addition, practical implications for resolving the problem of structural career plateau were provided.