• 제목/요약/키워드: Static Behaviors

검색결과 433건 처리시간 0.035초

Static behaviors of self-anchored and partially earth-anchored long-span cable-stayed bridges

  • Xie, Xu;Yamaguchi, Hiroki;Nagai, Masatsugu
    • Structural Engineering and Mechanics
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    • 제5권6호
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    • pp.767-774
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    • 1997
  • In this paper, three dimensional static behaviors of the self-anchored and partially earth-anchored cable-stayed bridges, with a span of 1400 meters, under wind loading are studied by using a 3D geometrical nonlinear analysis. In this analysis, the bridges both after completion and under construction are dealt with. The wind resistant characteristics of the both cable-stayed systems are made clear. In particular, the characteristics of the partially earth-anchored cable systems, which is expected to be a promising solution for extending the span of the cable-stayed systems further, is presented.

Failure behaviors of C/C composite tube under lateral compression loading

  • Gao, Yantao;Guan, Yuexia;Li, Ke;Liu, Min;Zhang, Can;Song, Jinliang
    • Nuclear Engineering and Technology
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    • 제51권7호
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    • pp.1822-1827
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    • 2019
  • Mechanical responses and failure behaviors of advanced C/C composite tube are very important for structural component design in nuclear reactor. In this study, an experimental investigation was conducted to study mechanical properties of C/C composite tube. Quasi-static compression loading was applied to a type of advanced composite tube to determine the response of the quasi-static load displacement curve during progressive damage. Acoustic emissions (AE) signals were captured and analyzed to characterize the crack formation and crack development. In addition, the crack propagation of the specimens was monitored by imaging technique and failure mode of the specimen was analyzed. FEM is appled to simulate the stress distribution. Results show that advanced C/C composite tube exhibits considerable energy absorption capability and stability in load-carrying capacity.

OPERATOR BEHAVIORS OBSERVED IN FOLLOWING EMERGENCY OPERATING PROCEDURE UNDER A SIMULATED EMERGENCY

  • Choi, Sun-Yeong;Park, Jin-Kyun
    • Nuclear Engineering and Technology
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    • 제44권4호
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    • pp.379-386
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    • 2012
  • A symptom-based procedure with a critical safety function monitoring system has been established to reduce the operator's diagnosis and cognitive burden since the Three-Mile Island (TMI) accident. However, it has been reported that a symptom-based procedure also requires an operator's cognitive efforts to cope with off-normal events. This can be caused by mismatches between a static model, an emergency operating procedure (EOP), and a dynamic process, the nature of an ongoing situation. The purpose of this study is to share the evidence of mismatches that may result in an excessive cognitive burden in conducting EOPs. For this purpose, we analyzed simulated emergency operation records and observed some operator behaviors during the EOP operation: continuous steps, improper description, parameter check at a fixed time, decision by information previously obtained, execution complexity, operation by the operator's knowledge, notes and cautions, and a foldout page. Since observations in this study are comparable to the results of an existing study, it is expected that the operational behaviors observed in this study are generic features of operators who have to cope with a dynamic situation using a static procedure.

노인의 건강신념과 건강관행에 관한 연구 (A Study on Health Belief and Health Behaviors of the Elderly)

  • 왕명자;차남현
    • 동서간호학연구지
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    • 제8권1호
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    • pp.103-112
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    • 2003
  • This paper focused on providing the groundwork for the development of proper nursing interventions to enhance the quality of life for the elderly by identifying the factors that may affect their health beliefs and behaviors. A survey was conducted on a group of people aged between 60 and 86 years residing in S and K cities from January to March of 2003, who agreed to participate in the research. Data was collected using instruments measuring health beliefs and health behaviors, and was analyzed by using SPSS. The results of this study are as follow. 1) Those in the group were aged between60 and 86 years, and the average age was 66.94 years old. Most of them were living together with their spouses. From the survey, 83.5% replied "above average" on the question regarding their current health condition, whereas, 46.0% mentioned that they had some sort of diseases. 2) Overall average score of the health belief was 516.05, with a mean $3.71{\pm}4.07$. This indicates that the studied group held a high level of health belief, which affects their attitude and intention to lead a healthy life by placing the present life under control in harmony with nature. 3) Overall average score of the health behaviors was 392.24 with a mean $2.82{\pm}.52$. For health purposes, the behaviors that the elderly people were taking were mostly static ones requiring a low level of activity. The analysis showed that they generally were involved in self-trained, individualized health care. Thus, the elderly place a higher priority on regular dietary behaviors than on physical activity. 4) The correlation between health belief, a cognitive aspect on health, and health behaviors, a behavioral aspect showed a very high linear relationship (r=.520, p<.000). Consequently, it is found that those who have higher cognitive health belief are involved in higher level of behavioral health practice. These findings concluded that the Korean elderly have good health beliefs, well controlling their minds and being harmonious with nature. Health behaviors that they are engaged in are mostly static, requiring low level activity, while they place higher priority on regular dietary habits and conducting self-trained individualized health care. Important factor affecting their health beliefs and health behaviors was found to be their health practice. Since higher health belief is highly related with good health behaviors, development of health activity programs is in need as a means for an efficient health improvement, where motivating environment may be established to enhance the health belief of the elderly and to satisfy individual values.

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3차원 케이블망의 정적 비선형 해석 및 초기 평형상태의 결정 (Non-linear Static Analysis and Determination of Initial Equilibrium States of Space Cable Nets)

  • 김문영;김남일
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 가을 학술발표회 논문집
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    • pp.134-141
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    • 1997
  • A geometrically non-linear finite element formulation of spatial cable networks is presented using three cable elements. Firstly, derivation procedures of tangent stiffness and mass matrices for the space truss element and the elastic catenary cable element, and the isoparametric cable element are summarized. The load incremental method based on Newton-Raphson iteration method and the dynamic relaxation method are presented in order to determine the initial static state of cable nets subjected to self-weights and support motions. Furthermore, static non-linear analysis of cable structures under additional live loads are performed based on the initial configuration. Challenging example problems are presented and discussed in order to demonstrate the feasibility of the present finite element method and investigate static non-linear behaviors of cable nets.

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계류삭의 비선형운동특성해석에 관한 연구 (A Study on Nonlinear Analysis of Mooring Lines)

  • 이상무;김용철;김영환;홍석원;김훈철
    • 대한조선학회지
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    • 제23권1호
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    • pp.3-12
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    • 1986
  • This paper investigates the static configurations and the dynamic behaviors of a single point mooring line. To obtain the static configuration and static tension distribution along the mooring line, including the effect of fluid nonlinear drag and the elasticity of the line, the Runge-Kutta fourth order numerical method was used. The relationship between the horizontal excursion and the horizontal restoring force component of the mooring line, which is very important to a mooring line design, and the effect of a subsurface buoy on the static configuration are presented. In nonlinear dynamic analysis including nonlinear fluid drag acting on the line and geometrical nonlinearity for large deflections, finite element method using updated Lagrangian was used to obtain the solution. In the case of upper end harmonic excitation of the mooring line, the dynamic motion and the tension were also presented.

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틸팅 차량용 차체의 하이브리드 복합재 접합체결부의 내구성 평가 (Fatigue Assessment of Hybrid Composite Joint for the Tilting Car Body)

  • 정달우;최낙삼;김정석;서승일;조세현
    • 한국신뢰성학회:학술대회논문집
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    • 한국신뢰성학회 2006년도 학술발표대회 논문집
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    • pp.357-361
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    • 2006
  • Fatigue fracture behavior of a hybrid joint part with bolting was evaluated in comparison to the case of static fracture. Hybrid joint part specimens for bending test were made with layers of CFRP and aluminum honeycomb. Characteristic fracture behaviors of those specimens were obviously different under static and cyclic loads. Static bending load showed the shear deformation at the honeycomb core, whereas cyclic bending load caused the delamination between CFRP skin layers and honeycomb core. Experimental results obtained by static and fatigue tests were considered in modifications of design parameters of the hybrid joint.

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플레이트 형상에 따른 Headed Bars의 파괴거동에 관한 연구 (Fracture Behaviors of Headed Bars with Different Plate Types)

  • 박현규;윤영수;류영섭;이만섭
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 봄 학술발표회 논문집
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    • pp.935-940
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    • 2002
  • This paper presents the failure mode on Headed Bars and prediction of tensile capacity, which is governed by concrete cone failure. 17 different plate types, three different concrete strengths and three different welding types of specimens were simulated. Static tensile load was applied Headed Bars were manufactured in different areas, and their shape and thickness are based on ASTM 970-98. Calculation of embedment length in concrete is conducted based on CSA 23.3-94, and static tensile load was applied. Tested pullout capacities were compared to the values determined using current design methods such as ACI-349 and CCD method.

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Equivalent static wind load estimation in wind-resistant design of single-layer reticulated shells

  • Li, Yuan-Qi;Tamura, Yukio
    • Wind and Structures
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    • 제8권6호
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    • pp.443-454
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    • 2005
  • Wind loading is very important, even dominant in some cases, to large-span single-layer reticulated shells. At present, usually equivalent static methods based on quasi-steady assumption, as the same as the wind-resistant design of low-rise buildings, are used in the structural design. However, it is not easy to estimate a suitable equivalent static wind load so that the effects of fluctuating component of wind on the structural behaviors, especially on structural stability, can be well considered. In this paper, the effects of fluctuating component of wind load on the stability of a single-layer reticulated spherical shell model are investigated based on wind pressure distribution measured simultaneously in the wind tunnel. Several methods used to estimate the equivalent static wind load distribution for equivalent static wind-resistant design are reviewed. A new simple method from the stability point of view is presented to estimate the most unfavorable wind load distribution considering the effects of fluctuating component on the stability of shells. Finally, with comparisive analyses using different methods, the efficiency of the presented method for wind-resistant analysis of single-layer reticulated shells is established.