• 제목/요약/키워드: Compression displacement

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일축(一軸) 압축(壓縮)을 받는 판(板)의 유한대판법(有限帶板法)에 의한 기하학적(幾何學的) 비선형(非線型) 해석(解析) (Geometrically Nonlinear Analysis of Plates Subjected to Uniaxial Compression by Finite Strip Method)

  • 이용재
    • 대한토목학회논문집
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    • 제5권3호
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    • pp.107-115
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    • 1985
  • 초기(初期)처짐을 가지는 평판(平板)이 일보면내압축하중(一輔面內壓縮荷重)을 받을 때의 거동을 살피기 위하여 새로운 변위함수(變位凾數)를 도입(導入)한 유한대판법(有限帶板法)을 정식화(正式化)하고, 이 이론(理論)에 따라 컴퓨터 프로그램을 편성(編成)하여 여러 경우에 대한 평판(平板)의 거동을 계산(計算)하고 이미 발표된 결과(結果)와 비교해 보았는데 그 요점은 다음과 같다. 1. Curvature effect를 고려하여 면외변위(面外變位)함수로부터 유도한 식을 참고로 하여 새로운 면내변위(面內變位) 함수를 가정하고 이것을 대판요소(帶板要素)의 변위(變位)함수로 사용한 유한대판법(有限帶板法)을 안식화(定式化)하였다. 2. 위에서 안식화(定式化)한 유한대판법(有限帶板法)에 따라 편성(編成)한 프로그램을 써서 수치해석한 결과 변위증분방식(變位增分方式)이 하중증분방식(荷重增分方式)보다 수렴이 빨랐다. 3. 일축압축(一軸壓縮)을 받는 평판(平板)을 여려 경우에 대해 위의방법으로 해석한 결과는 해석적(解析的) 방법(方法)이나 Crisfield(D)에 의(依)한 유한요소법(有限要素法)으로 얻어진 결과와 잘일치 하였다. 따라서 위의 방법은 평판의 비선형해석을 위한 하나의 유용한 방법으로 생각된다.

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Seismic behavior of steel truss reinforced concrete L-shaped columns under combined loading

  • Ning, Fan;Chen, Zongping;Zhou, Ji;Xu, Dingyi
    • Steel and Composite Structures
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    • 제43권2호
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    • pp.139-152
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    • 2022
  • Steel-reinforced concrete (SRC) L-shaped column is the vertical load-bearing member with high spatial adaptability. The seismic behavior of SRC L-shaped column is complex because of their irregular cross sections. In this study, the hysteretic performance of six steel truss reinforced concrete L-shaped columns specimens under the combined loading of compression, bending, shear, and torsion was tested. There were two parameters, i.e., the moment ratio of torsion to bending (γ) and the aspect ratio (column length-to-depth ratio (φ)). The failure process, torsion-displacement hysteresis curves, and bending-displacement hysteresis curves of specimens were obtained, and the failure patterns, hysteresis curves, rigidity degradation, ductility, and energy dissipation were analyzed. The experimental research indicates that the failure mode of the specimen changes from bending failure to bending-shear failure and finally bending-torsion failure with the increase of γ. The torsion-displacement hysteresis curves were pinched in the middle, formed a slip platform, and the phenomenon of "load drop" occurred after the peak load. The bending-displacement hysteresis curves were plump, which shows that the bending capacity of the specimen is better than torsion capacity. The results show that the steel truss reinforced concrete L-shaped columns have good collapse resistance, and the ultimate interstory drift ratio more than that of the Chinese Code of Seismic Design of Building (GB50011-2014), which is sufficient. The average value of displacement ductility coefficient is larger than rotation angle ductility coefficient, indicating that the specimen has a better bending deformation resistance. The specimen that has a more regular section with a small φ has better potential to bear bending moment and torsion evenly and consume more energy under a combined action.

가솔린 직접분사식 압축착화 엔진의 가능한 운전영역에 관한 기초실험 연구 (A Basic Experimental Study on Potential Operating Range in Gasoline Direct-Injection Compression Ignition (GDICI) Engine)

  • 차준표;윤성준;이석훤;박성욱
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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    • pp.33-35
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    • 2013
  • The present work is an experimental investigation on potential operating range using directly injected gasoline fuel in a single-cylinder compression ignition (CI) engine. The objectives of present study were to apply auto-ignited combustion to gasoline fuel and to evaluate potential operating range. In order to auto-ignite gasoline fuel in CI engine, the fuel direct-injection system and the intake air system were modified that a flow rate and temperature of intake air were regulated. The heat-release rate (HRR), net indicated mean effective pressure (IMEP), start of combustion (SOC), and combustion duration were derived from in-cylinder pressure data in a test engine, which has 373.33cc displacement volume and 17.8 compression ratio. The exhaust emission characteristics were obtained emission gas analyzer and smoke meter on the exhaust line system.

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베인 이간 현상에 관한 연구 (Detachment of Vane Tip in a Positive Displacement Vane Pump)

  • 문호지;조명래;한동철
    • 한국윤활학회:학술대회논문집
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    • 한국윤활학회 1997년도 제25회 춘계학술대회
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    • pp.204-209
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    • 1997
  • This paper reports on the theoretical study of the vane motions in a positive displacement vane pump. Vane detachment cause the pressure fluctuation, noise, wear in cam ring, and decrease the volumetric efficiency. Dynamic equation of vane motion and flow continuity equation have been modeled and solved simultaneously using 4th order Runge-Kutta method. As results of analysis, vane detachment occurs due to pressure overshoot by excess compression in the pumping chamber. Amount of vane detachment has been reduced by decreasing the pressure overshoot.

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변형을 고려한 스트럿-타이 모델 (Concepts on Deformation Dependent Strut-and-Tie Models)

  • 홍성걸;장상기
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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    • pp.209-212
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    • 2005
  • This paper presents, basic concepts on deformation models for D-regions critical to shear. Strut-and-tie models are used to construct for deformation estimation at yielding and ultimate deformation. A generic: strut-and-tie model is proposed to investigate deformation patterns and failure mode identification. Superposition of the basic models enables us to explain deformation limits of arch action and truss action. Displacement at yielding is assessed by consideration of deformation of reinforcing steel only while the ultimate displacement is calculated by limits of ultimate strain of concrete in compression and failure mechanisms.

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변위전류에 의한 DMPE, DLPE 지질막의 수면상 거동 연구 (A study on the movement of Liquid DMPE and DLPE monolayer on a water subphase by Maxwell Displacement Currents)

  • 이호식;김우연;이원재;김태완;;강도열
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1996년도 추계학술대회 논문집
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    • pp.191-194
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    • 1996
  • Maxwell displacement current clearly shows the onset of a first order phase transition from gaseous to gaseous-fluid phase, and polar ordering of liquid molecules in the solid phase coexisting with fluid. For further monolayer compression in the fluid/solid phase transition, the condensation of domains was suggested.

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전단지배형 부재의 변형능력 산정을 위한 모형 (Deformability Models of Shear Controlled Members)

  • 홍성걸
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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    • pp.357-360
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    • 2004
  • Estimation of deformation capacity of non-flexural reinforced concrete members is proposed using basic concepts of limit analysis and the virtual work method. This new approach starts with construction of admissible stress field as for an equilibrium set. Failure mechanisms compatible with admissible stress fields are postulated as for displacement set. It is assumed that the ultimate deformations as result of failure mechanisms are controlled by ultimate strain of concrete in compression. The derived formula for deformability of deep beams in shear shows reasonable range of ultimate displacement.

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레이저 열-압착 본딩을 위한 압전 액추에이터로 구동되는 용융실리카 헤더의 취성특성에 관한 연구 (A study on the brittle characteristics of fused silica header driven by piezoelectric actuator for laser assisted TC bonding)

  • 이동원;하석재;박정연;윤길상
    • Design & Manufacturing
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    • 제13권4호
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    • pp.10-16
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    • 2019
  • Semiconductor chip is bonded to the substrate by melting solder bumps. In general, the chip bonding is applied by a Reflow process or a Thermo-Compression(TC) bonding process. In this paper, we introduce a Laser Assisted Thermo-Compression bonding (LATCB) process to improve the anxiety of the existing process(Reflow, TC bonding). In the LATCB process, the chip is bonded to the substrate by irradiating a laser with a uniform energy density in the same area as the chip to melt only the solder bumps and press the chip with a Transparent Compression Module (TCM). The TCM consists of a fused silica header for penetrating the laser and pressurizing the chip, and a piezoelectric actuator (P.A.) coupled to both ends of the header for micro displacement control of the header. In addition, TCM is a structure that can pressurize the chip and deliver it to the chip and solder bumps without losing the energy of the laser. Fused silica, which is brittle, is vulnerable to deformation, so the header may be damaged when an external force is applied for pressurization or a displacement differenced is caused by piezoelectric actuators at both ends. On the other hand, in order to avoid interference between the header and the adjacent chip when pressing the chip using the TCM, the header has a notch at the bottom, and breakage due to stress concentration of the notch is expected. In this study, the thickness and notch length that the header does not break when the external force (500 N) is applied to both ends of the header are optimized using structural analysis and Coulomb-Mohr failure theory. In addition, the maximum displacement difference of the P.A.s at both ends where no break occurred in the header was derived. As a result, the thickness of the header is 11 mm, and the maximum displacement difference between both ends is 8 um.

도수교정의 검사원리 (Examination Principles of Manipulation)

  • 박지환
    • 대한정형도수물리치료학회지
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    • 제1권1호
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    • pp.49-63
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    • 1995
  • Examination at the spine is dependent on assessment of function. At all spine levels a number of general anatomical considerations hold sway which together dictate the format of the evaluation. Because disc lesions are common and generally responsive to treatment, the examination sets out to differentiate between disc lesions and the other sources of pain as well as establishing the particular treatment that will benefit any given displacement. As elsewhere in the body, displacements give rise to certain characteristic symtoms and signs. First, the history is indicative. Second, any loose fragment in the joint restricts spinal movement in some but not all directions, producing the non-capsular pattern characteristic of internal derangement. Third, a displacement protruding posteriorly interferes with the dura mater ; apart from pain, this adversely affects the dura's normal painless mobility. Fourth, a displacement protruding laterally connects with the appropriate nerve root emerging from the dura mater. Finally, compression of the spinal cord strongly contraindicates manipulation, the primary treatment for cartilaginous displacements.

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