• Title/Summary/Keyword: Fourth-order differential equations

Search Result 40, Processing Time 0.025 seconds

On a new fourth order self-adaptive time integration algorithm

  • Zhong, Wanxie;Zhu, Jianping
    • Structural Engineering and Mechanics
    • /
    • v.4 no.6
    • /
    • pp.589-600
    • /
    • 1996
  • An explicit 4th order time integration scheme for solving the convection-diffusion equation is discussed in this paper. A system of ordinary differential equations are derived first by discretizing the spatial derivatives of the relevant PDE using the finite difference method. The integration of the ODEs is then carried out using a 4th order scheme and a self-adaptive technique based on the spatial grid spacing. For a non-uniform spatial grid, different time step sizes are used for the integration of the ODEs defined at different spatial points, which improves the computational efficiency significantly. A numerical example is also discussed in the paper to demonstrate the implementation and effectiveness of the method.

Analysis of Rectangular Plates under Distributed Loads of Various Intensity with Interior Supports at Arbitrary Positions (분포하중(分布荷重)을 받는 구형판(矩形板)의 탄성해석(彈性解析))

  • Suk-Yoon,Chang
    • Bulletin of the Society of Naval Architects of Korea
    • /
    • v.13 no.1
    • /
    • pp.17-23
    • /
    • 1976
  • Some methods of analysis of rectangular plates under distributed load of various intensity with interior supports are presented herein. Analysis of many structures such as bottom, side shell, and deck plate of ship hull and flat slab, with or without internal supports, Floor systems of bridges, included crthotropic bridges is a problem of plate with elastic supports or continuous edges. When the four edges of rectangular plate is simply supported, the double Fourier series solution developed by Navier can represent an exact result of this problem. If two opposite edges are simply supported, Levy's method is available to give an "exact" solution. When the loading condition and supporting condition of a plate does not fall into these cases, no simple analytic method seems to be feasible. Analysis of a simply supported rectangular plate under irregularly distributed loads of various intensity with internal supports is carried out by applying Navier solution well as the "Principle of Superposition." Finite difference technique is used to solve plates under irregularly distributed loads of various intensity with internal supports and with various boundary conditions. When finite difference technique is applied to the Lagrange's plate bending equation, any of fourth order derivative term in this equation produces at least five pivotal points leading to some troubles when the resulting linear algebraic equations are to be solved. This problem was solved by reducing the order of the derivatives to two: the fourth order partial differential equation with one dependent variable, namely deflection, is changed to an equivalent pair of second order partial differential equations with two dependent variables. Finite difference technique is then applied to transform these equations to a set of simultaneous linear algebraic equations. Principle of Superposition is then applied to handle the problems caused by concentrated loads and interior supports. This method can be used for the cases of plates under irregularly distributed loads of various intensity with arbitrary conditions such as elastic supports, or continuous edges with or without interior supports, and this method can also be solve the influence values of deflection, moment and etc. at arbitrary position of plates under the live load.

  • PDF

ANALYTIC SOLUTION OF HIGH ORDER FRACTIONAL BOUNDARY VALUE PROBLEMS

  • Muner M. Abou Hasan;Soliman A. Alkhatib
    • Nonlinear Functional Analysis and Applications
    • /
    • v.28 no.3
    • /
    • pp.601-612
    • /
    • 2023
  • The existence of solution of the fractional order differential equations is very important mathematical field. Thus, in this work, we discuss, under some hypothesis, the existence of a positive solution for the nonlinear fourth order fractional boundary value problem which includes the p-Laplacian transform. The proposed method in the article is based on the fixed point theorem. More precisely, Krasnosilsky's theorem on a fixed point and some properties of the Green's function were used to study the existence of a solution for fourth order fractional boundary value problem. The main theoretical result of the paper is explained by example.

Stability Analysis of Cracked Beams with Subtangential Follower Force and Tip Mass (경사 종동력과 끝질량을 갖는 크랙 보의 안정성 해석)

  • Son, In-Soo;Yoon, Han-Ik;No, Tae-Woo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.33 no.12
    • /
    • pp.1410-1416
    • /
    • 2009
  • In this paper, the purpose is to investigate the stability and variation of natural frequency of a cracked cantilever beams subjected to follower force and tip mass. In addition, an analysis of the flutter instability(flutter critical follower force) of a cracked cantilever beam as slenderness ratio and crack severity is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force is derived via Hamilton's principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. Finally, the influence of the slenderness ratio and crack severity on the critical follower force, stability and the natural frequency of a beam are investigated.

Effects of Slenderness ratio on Dynamic Behavior of Cantilever Beam Subjected to Follower Force (종동력을 받는 외팔보의 진동특성에 미치는 세장비의 영향)

  • Son, In-Soo;Yoon, Han-Ik;Ahn, Tae-Su
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2008.04a
    • /
    • pp.575-578
    • /
    • 2008
  • In this paper, the purpose is to investigate the stability and variation of natural frequency of a Timoshenko cantilever beam subjected to follower force and tip mass. In addition, an analysis of the flutter instability(flutter critical follower force) of a cantilever beam as slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force is derived via Hamilton;s principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. Finally, the influence of the slenderness ratio and tip mass on the critical follower force and the natural frequency of a Timoshenko beam are investigated.

  • PDF

Effects of Slenderness Ratio on Stability of Cracked Beams Subjected to Sub-tangential Follower Force (경사종동력을 받는 크랙 외팔보의 안정성에 미치는 세장비의 영향)

  • Gal, Young-Min;Ahn, Sung-Jin;Yoon, Han-Ik;Son, In-Soo
    • Proceedings of the KSME Conference
    • /
    • 2008.11a
    • /
    • pp.961-966
    • /
    • 2008
  • In this paper, the purpose is to investigate the stability and variation of natural frequency of a Timoshenko cantilever beam subjected to Subtangential follower force and tip mass. In addition, an analysis of the flutter instability(flutter critical follower force) of a cantilever beam as slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force is derived via Hamilton;s principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. Finally, the influence of the slenderness ratio and tip mass on the critical follower force and the natural frequency of a Timoshenko beam are investigated.

  • PDF

Effects of Slenderness Ratio on Dynamic Behavior of Cracked Beams Subjected to Subtangential Follower Force (경사종동력과 크랙을 가진 보의 진동특성에 미치는 세장비의 영향)

  • Son, In-Soo;Yoon, Han-Ik
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.26 no.9
    • /
    • pp.112-120
    • /
    • 2009
  • In this paper the purpose is to investigate the stability and variation of natural frequency of a cracked Timoshenko cantilever beams subjected to subtangential follower force. In addition, an analysis of the stability of a cantilever beam as the crack effect and slenderness ratio is investigated. The governing differential equations of a Timoshenko beam subjected to an end tangential follower force are derived via Hamilton's principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. By using the results of this paper, we can obtain the judgment base that the choice of beam models for the effect of slenderness ratio and crack.

Experimental Study on Crack Detection of Clamped-clamped Beams (양단 고정보의 크랙 검출에 대한 실험적 연구)

  • Son, In-Soo;Ahn, Sung-Jin;Yoon, Han-Ik
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.27 no.6
    • /
    • pp.47-54
    • /
    • 2010
  • In this paper, the purpose is to study a method for detection of crack in clamped-clamped beams using the vibration characteristics. The natural frequency of beam is obtained by FEM and experiment. The governing differential equations of a Timoshenko beam are derived via Hamilton's principle. The two coupled governing differential equations are reduced to one fourth order ordinary differential equation in terms of the flexural displacement. The crack is assumed to be in the first mode of fracture and to be always opened during the vibrations. The differences between the actual and predicted crack positions and sizes are less than 9.8% and 28%, respectively.

STEADY NONLINEAR HYDROMAGNETIC FLOW OVER A STRETCHING SHEET WITH VARIABLE THICKNESS AND VARIABLE SURFACE TEMPERATURE

  • Anjali Devi, S.P.;Prakash, M.
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.18 no.3
    • /
    • pp.245-256
    • /
    • 2014
  • This work is focused on the boundary layer and heat transfer characteristics of hydromagnetic flow over a stretching sheet with variable thickness. Steady, two dimensional, nonlinear, laminar flow of an incompressible, viscous and electrically conducting fluid over a stretching sheet with variable thickness and power law velocity in the presence of variable magnetic field and variable temperature is considered. Governing equations of the problem are converted into ordinary differential equations utilizing similarity transformations. The resulting non-linear differential equations are solved numerically by utilizing Nachtsheim-Swigert shooting iterative scheme for satisfaction of asymptotic boundary conditions along with fourth order Runge-Kutta integration method. Numerical computations are carried out for various values of the physical parameters and the effects over the velocity and temperature are analyzed. Numerical values of dimensionless skin friction coefficient and non-dimensional rate of heat transfer are also obtained.

Numerical Analysis of Tapered Circular Arch with Fixed Ends (양단고정 변단면 도호아-치의 수치해석에 관한 연구)

  • 박문호;이병구
    • Magazine of the Korean Society of Agricultural Engineers
    • /
    • v.19 no.3
    • /
    • pp.4462-4471
    • /
    • 1977
  • The governing differential equations for the tapered circular arch with fixed ends have been derived, and a numerical procedure for the solution of these equations have been developed. The governing differential equations were solved numerically by an initial value integration procedure and Shooting Methods for boundary value problems. The Rungekutta fourth order integration technique was used. The methods was programmed for a Cyber 73-18 computer System, and all esults were obtained on this computer. A detailed study has been made for a fixed arch with an angle of opening equal to 0.7 radian, and the results are presented in detail in tables and curves. It is hoped that the results presented herein is applied to the deformations of gives point from the tri-axial direction of tapered circular arch with fixed ends, bending moment, and torsional moment, and that at the same time results to be used for archwise structures in steel structure.

  • PDF