• Title/Summary/Keyword: 뉴마크 법

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Undamped Dynamic Response of Anisotropic Laminated Composite Plates and Shell Structures using a Higher-order Shear Deformation Theory (비등방성 복합적층판 및 쉘의 고차전단변형을 고려한 비감쇄 동적응답)

  • Yoon, Seok Ho;Han, Seong Cheon;Chang, Suk Yoon
    • Journal of Korean Society of Steel Construction
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    • v.9 no.3 s.32
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    • pp.333-340
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    • 1997
  • This paper will expand the third-order shear deformation theory by the double-Fourier series and reduce to the solution of a system of ordinary differential equations in time, which are integrated numerically using Newmark's direct integration method and clarify the undamped dynamic responses for the cross-ply and antisymmetric angle-ply laminated composite plates and shells with simply supported boundary condition. Numerical results for deflections are presented showing the effect of side-to-thickness ratio, aspect ratio, material anisotropy, and lamination scheme.

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A study on the Transient Torsional Vibrations of Four Stroke Marine Diesel Engines (선박용 4행정 디젤엔진의 과도 비틀림 진동에 관할 연구)

  • Lee, D.C.;Yu, J.D.;Jeon, H.J.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.44-50
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    • 2002
  • Theoretical analysis on the transient torsional vibration was started from early 1960's for high power synchronous motor application. As for marine engineering, simulation and measuring techniques of transient torsional vibration have been steadily studied by manufacturer of flexible coupling and designer of four stroke marine diesel engine. In this paper, the simulation method of transient torsional vibration for four stroke marine diesel engine application using Newmark method is introduced.

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Theoretical Analysis about Transient Torsional Vibrations of Two Stroke Low Speed Diesel Engines (저속 2행정 디젤엔진의 과도 비틀림 진동에 관한 이론적 해석)

  • 이돈출;유정대;전효중
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.05a
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    • pp.830-835
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    • 2002
  • Theoretical analysis about transient torsional vibration was started from early 1960's for high power synchronous motor application. Especially, its simulation and measuring techniques in marine engineering field have been steadily studied by classification societies and designers of large diesel engine. In this paper, the simulation method of transient torsional vibration of two stroke low speed diesel engine using the Newmark method are introduced.

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Fast Simulation of Output Voltage for High-Shock Piezoresistive Microaccelerometer Using Mode Superposition Method and Least Square Method (모드중첩법 및 최소자승법을 통한 고충격 압저항 미소가속도계의 출력전압 해석)

  • Han, Jeong-Sam;Kwon, Ki-Beom
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.36 no.7
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    • pp.777-787
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    • 2012
  • The transient analysis for the output voltage of a piezoresistive microaccelerometer takes a relatively high computation time because at least two iterations are required to calculate the piezoresistive-structural coupled response at each time step. In this study, the high computational cost for calculating the transient output voltage is considerably reduced by an approach integrating the mode superposition method and the least square method. In the approach, data on static displacement and output voltage calculated by piezoresistive-structural coupled simulation for three acceleration inputs are used to develop a quadratic regression model, relating the output voltage to the displacement at a certain observation point. The transient output voltage is then approximated by a regression model using the displacement response cheaply calculated by the mode superposition method. A high-impact microaccelerometer subject to several types of acceleration inputs such as 100,000 G shock, sine, step, and square pulses are adopted as a numerical example to represent the efficiency and accuracy of the suggested approach.

The Comparision of Analysis Methods in dynamic Design of Dam based on Shaking Table tests (진동대시험에 근거한 댐의 내진설계시 해석 방법의 비교)

  • Hwang, Seong-Choon;Oh, Byung-Hyun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.732-737
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    • 2005
  • This paper performed pseudo static analysis and dynamic analysis for CFRD and evaluated reliability with the results of Shaking Table Test. The Seismic coefficient method, modified seismic coefficient method, Newmark method of Pseudo static analysis and frequency domain response analysis, time domain history analysis of dynamic analysis were used. The analysis results were differ between analysis method, but the trends of acceleration and displacement were good agreement with the results of shaking table test.

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Transient Response Analysis of Frame Structures Using the Finite Element-transfer Stiffness Coefficient Method (FE-TSCM) (유한요소-전달강성계수법을 이용한 골조 구조물의 과도응답해석)

  • 최명수;문덕홍;김성진
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.12 no.9
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    • pp.674-684
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    • 2002
  • In order to decrease remarkably the computation time and storage used in the direct integration method without the loss of accuracy, authors suggest a new transient analysis algorithm. This algorithm is derived from the combination of three techniques, that is, the transfer technique of the transfer stiffness coefficient method, the modeling technique of the finite element method, and the numerical integration technique of the Newmark method. In this paper, the transient analysis algorithm of a frame structure is formulated by the proposed method. The accuracy and computation efficiency of the proposed method are demonstrated through the comparing with the computation results by the direct integration method for three computation models under various excitations.

Numerical Analysis of Hydrodynamic Characteristics for Various Types of Jack-up Legs (다양한 형상의 Jack-up Leg에 대한 해양 동역학적 수치해석)

  • Kim, Ji-Seok;Park, Min-Su;Koo, Weoncheol
    • Journal of Ocean Engineering and Technology
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    • v.28 no.5
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    • pp.371-377
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    • 2014
  • In this study, the hydrodynamic characteristics of various types of jack-up legs for a wind turbine installation vessel were analyzed. Using the modified Morison equation, the wave and current excitation forces on the jack-up legs were calculated. A modal analysis was performed to predict the dynamic responses for various types of jack-up legs. The Newmark-beta time integration scheme was used to solve the equation of motion in waves in the time domain. The maximum displacement and maximum bending stress were computed for four different types of legs, and their results were compared to select an optimum leg type. Finally, a six-leg jack-up rig with the selected optimal legs was modeled, and its natural period and hydrodynamic behaviors were evaluated.

Vibration Analysis of a Flexible Structure in a Motion (유연 구조물의 운동중 발생하는 진동의 해석)

  • 이신영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.6
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    • pp.1503-1509
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    • 1994
  • An analysis method is suggested and experimentally studied in order to solve a vibration problem of a flexible structure while it is moving. In this method, substructure synthesis method, modal analysis method and Newmark's integral method were used. Total deformation of a structure was composed of quasistatic component and dynamic component. Rigid body modes were considered in calculation of dynamic component. Combining those two component, deformation behavior and a real structural model of a transfer feeder showed good agreements with computational results.

A Study on a Nonlinear Cable Finite Element (非線形 케이블 有限要素에 관한 硏究)

  • 장승필;박정일
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.1 no.1
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    • pp.93-101
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    • 1989
  • A geometrically nonlinear cable finite element is presented to use in the static or dynamic modeling of offshore and onshore structures such as guyed tower, tension leg platform or mooring buoy, submarine cable, cable-stayed bridge, suspension bridge, cable roof and so on. The cable finite element is derived directly from the compatibility equations and flexibility matrix of elastic catenary cable theory for the arbitary plane loading and geome try. A general and virsatile computer program has been developed to perform the analyses of cable member itself or cable guyed or suspened structures, in which Newmark-$\beta$ method is used to obtain a time domain solution and Newton-Raphson iteration method is used to solve the nonlinear system of compatibility equations of cable and algebraic static or dynamic equations at each time step. The results from the static and dynamic analysis of a cable member by the computer program are summarized and presented.

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The Effects of Braking of Trains and Roughness of Rails on the Dynamic Behaviors of Bridges (열차의 제동 및 궤도의 조도가 교량의 동적 거동에 미치는 영향)

  • Kim, Doo-Kie;Yang, Sin-Chu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.5
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    • pp.93-101
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    • 2010
  • The effects of braking of trains and roughness of rails on the dynamic behavior of bridges are studied. The train-bridge interaction is considered by solving Lagrange's equation of motions. Newmark's direct integration is used to solve the governing equations. Dynamic train loads acting on piers at each time step are evaluated, and the wheel-rail roughness effect is considered by using the PSD curve of the rail. The model of braking forces in bridge section is based on the change of deceleration mentioned in ASTM(American Society for Testing and Materials) E503-82. Only skidding frictions without considering rolling frictions are modeled, and the friction coefficient of 0.25 is assumed. Parametric studies in a simply supported PC Box girder bridge are carried out to verify the present method and to analyze the effects of train speed, wheel-rail roughness, braking forces on dynamic train loads.