• 제목/요약/키워드: Structural Constraint

검색결과 395건 처리시간 0.03초

Push-out tests on stud shear connectors with constrained structure of steel-concrete composite beams

  • Qi, Jingjing;Xie, Zuwei;Cao, Hua;Huang, Zhi;Lv, Weirong;Shi, Weihua
    • Structural Engineering and Mechanics
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    • 제83권6호
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    • pp.789-798
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    • 2022
  • The stud shear connector is the main force transfer member in the steel-concrete composite member, and the mechanical behavior is very complicated in the concrete. The concrete around the stud is subjected to the pry-out local pressure concentration of the stud, which can easily produce splitting mirco-cracks. In order to solve the problem of pry-out local splitting of stud shear connector, a kind of stud shear connector with constraint measure is proposed in this paper. Through the push-out test, the interface shear behavior of the new stud shear connector between steel and concrete flange plate was studied, and the difference between the new stud shear connector and the traditional stud connector was compared. The results show that the stud shear connector with constraint measure can effectively avoid the adverse effect of local pressure splitting by relying on its own constraint measure. The shear stiffness of the interface between steel and concrete flange plates is greatly improved, which provides a theoretical basis for the design of strong connection coefficient of steel-concrete composite structures.

분산구조해석을 이용한 구조설계최적화 (Structural Design Optimization using Distributed Structural Analysis)

  • 박종희;정진덕;전한규;황진하
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 가을 학술발표회논문집
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    • pp.124-132
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    • 2000
  • Distributed processing approach for structural optimization is presented in this study. It is implemented on network of personal computers. The validity and efficiency of this approach are demonstrated and verified by test model of truss. Repeated structural analysis algorithm, which spend a lot of overall structural optimization processes, are based on substructuring scheme with domain-wise parallelism and converted to be adapted to hardware and software environments. The design information data are modularized and assigned to each computer in order to minize the communication cost. The communications between nodes are limited to static condensation and constraint-related data collection.

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PPA기법을 적용한 민간경호경비원의 여가제약과 중점개선 여가활동 참가지수 분석 (Analysis on the Leisure Constraint and Index Concentrate Here Improvement's Leisure Activities among the Private Security Agents Applying PPA Technique)

  • 김경식;김찬선;박영만
    • 한국콘텐츠학회논문지
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    • 제10권7호
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    • pp.317-325
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    • 2010
  • 이 연구는 PPA 기법을 적용하여 민간경호경비원들의 여가활동 집중개선 여가활동을 도출하고, 나아가 여가제약이 참가지수에 미치는 영향을 규명하는데 주된 목적이 있다. 이러한 과정을 통하여 최종적으로 민간경호경비원들의 여가후생복지 개선을 위한 정책투자우선순위를 도출하고자 한다. 따라서 본 연구는 2010년 2월 서울 소재 6개소 민간경비업체를 대상으로 판단표집법을 적용하여 최종분석에 사용된 사례 수는 총 267명이다. 수집된 자료는 SPSSWIN 17.0 프로그램으로 요인분석, 신뢰도 분석, 대응표본 t검증, PPA 분석, 회귀분석을 실시하였다. 설문지의 신뢰도는 Cronbach's $\alpha$값이 .768 이상으로 나타났다. 결론은 다음과 같다. 첫째, 민간경호경비원의 여가활동 참가 지수인 선호도와 참여도는 차이가 있다. 중점개선 여가활동은 헬스, 산책/조깅, 숙박관광, 당일여행 등이며, 노력지속 여가활동은 영화, 국내유명관광지, 이성교재, 외식, 대인관계, 스포츠 관람, 독서, 노래방, TV 비디오 시청, 음주 등이다. 개선요망 여가활동은 수상스포츠, 등산, 자전거, 축구, 사진촬영, 구기운동, 항공스포츠, 바둑/장기, 인라인스케이트, 요리 등이다. 둘째, 민간경호경비원의 여가제약은 여가활동 참가지수에 영향을 미친다. 여가제약의 하위요인인 개인내적 제약, 주변의식적 제약이 클수록 선호하는 여가활동 참가지수는 감소하는 반면, 구조적 제약, 시간 경제적 제약과 같은 어려움을 극복할 경우 여가활동 참가지수는 증가한다.

유연한 Timoshenko 빔의 동역학적 유한요소 정식화 및 해석 (The finite Element Formulation and Analysis of the Dynamic Flexible Timoshenko Beam)

  • Liu Zhi-Qiang;Yun Seong-Ho
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2004년도 봄 학술발표회 논문집
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    • pp.17-24
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    • 2004
  • This paper established the dynamic model of a flexible Timoshenko beam with geometrical nonlinearities subject to large overall motions by using the finite element method. The equations of motion are derived by using Hamilton principle based on expressing the kinetic and potential energies of the flexible beam in terms of generalized coordinates. The nonlinear constraint equations are adjoined to the system equations of motion by using Lagrange multipliers.

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일정체적을 갖는 단순지지 보-기둥의 자유진동 및 좌굴하중 (Free Vibrations and Buckling Loads of Simple Beam-Columns with Constant Volumes)

  • 이병구;오상진;모정만;이용
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1995년도 봄 학술발표회 논문집
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    • pp.62-69
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    • 1995
  • The differential equations governing both the free vibrations and buckling loads of the beam-columns with constant volumes are derived and solved numerically. The axial load effects are included in the differential equations. The Runge-Kutta method and Regula-Falsi method are used to compute the eigenvalues corresponding to the natural frequencies. and buckling loads. In numerical examples, the simple end constraint is considered.

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변형율 공간에서의 탄소성 강도 매트릭스 형성 (A Development of Elastoplastic Tangent Modulus in Finite Strain Space)

  • 주관정
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1990년도 봄 학술발표회 논문집
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    • pp.70-74
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    • 1990
  • The finite plasticity in strain space is viewed by formulating the consistency condition and the thermodynamic condition with respect to proposed state variables. The Naghi-Trapp work assumption is used to obtain a constraint equation, and the normality equation is formulated. Finally, an elastoplastic tangent modulus, which is based on the derived equations in strain space, is proposed.

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Decentralized Observer-Based Output-Feedback Formation Control of Multiple Unmanned Underwater Vehicles

  • Moon, Ji Hyun;Lee, Ho Jae
    • Journal of Electrical Engineering and Technology
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    • 제13권1호
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    • pp.493-500
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    • 2018
  • This paper addresses a decentralized observer-based output-feedback formation control problem for multiple unmanned underwater vehicles (UUVs). The complex nonlinear model for a UUV is feedback-linearized. It is assumed that each UUV in the formation exploits only the information regarding itself and the immediate predecessor, which imposes structural constraints on the formation controller gain matrices. The design condition is presented as a two-stage linear matrix inequalities problem. The synthesized controller demonstrates its own advantages through a numerical example.

엔진 블록의 중량 최소화에 관한 연구 (A study on the weight minimization of an engine block)

  • 오창근;박석주;박영범
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1996년도 추계학술대회논문집; 한국과학기술회관, 8 Nov. 1996
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    • pp.231-236
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    • 1996
  • Recently to develope an automobile with better properties, much researches and investments are executed in many countries. In this paper, the weight of an engine block intend to minimize without changing the natural frequency. The weight minimization of an engine block is started from much less initial thickness than original thickness of the model and performed by using the sensitive analysis method and the optimum structural modification method. It can be considered that the weight minimization is completed through this process, because the optimum structural modification method includes the constraint of minimum changing quantity.

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자동미분을 이용한 뼈대구조의 다단계 다목적 최적설계 (Multi-Level and Multi-Objective Optimization of Framed Structures Using Automatic Differentiation)

  • Cho, Hyo-Nam;Min, Dae-Hong;Lee, Kwang-Min;Kim, Hoan-Kee
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 봄 학술발표회논문집
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    • pp.177-186
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    • 2000
  • An improved multi-level(IML) optimization algorithm using automatic differentiation (AD) for multi-objective optimum design of framed structures is proposed in this paper. In order to optimize the steel frames under seismic load, two main objective functions need to be considered for minimizing the structural weight and maximizing the strain energy. For the efficiency of the proposed algorithm, multi-level optimization techniques using decomposition method that separately utilizes both system-level and element-level optimizations and an artificial constraint deletion technique are incorporated in the algorithm. And also to save the numerical efforts, an efficient reanalysis technique through approximated structural responses such as moments, frequencies, and strain energy with respect to intermediate variables is proposed in the paper. Sensitivity analysis of dynamic structural response is executed by AD that is a powerful technique for computing complex or implicit derivatives accurately and efficiently with minimal human effort. The efficiency and robustness of the IML algorithm, compared with a plain multi-level (PML) algorithm, is successfully demonstrated in the numerical examples.

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