• 제목/요약/키워드: integral solution

검색결과 604건 처리시간 0.025초

A two dimensional mixed boundary-value problem in a viscoelastic medium

  • Ataoglu, S.
    • Structural Engineering and Mechanics
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    • 제32권3호
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    • pp.407-427
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    • 2009
  • A fundamental solution for the transient, quasi-static, plane problems of linear viscoelasticity is introduced for a specific material. An integral equation has been found for any problem as a result of dynamic reciprocal identity which is written between this fundamental solution and the problem to be solved. The formulation is valid for the first, second and mixed boundary-value problems. This integral equation has been solved by BEM and algorithm of the BEM solution is explained on a sample, mixed boundary-value problem. The forms of time-displacement curves coincide with literature while time-surface traction curves being quite different in the results. The formulation does not have any singularity. Generalized functions and the integrals of them are used in a different form.

쌍적분 방정식을 이용한 완전도체쐐기의 점근해 유도, II : H-분극된 평면파 입사시 (Derivation of an Asymptotic solution for a Perfect Conducting Wedge by Using the Dual Integral Equation, Part II : H-Polarized Plane Wave Incidence)

  • 하헌태;나정웅
    • 전자공학회논문지D
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    • 제36D권1호
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    • pp.22-28
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    • 1999
  • H-분극된 평면파가 입사되는 완전도체쇄기에 대해 급수형태의 정확한 경계면 전자파를 파수영억역에서의 쌍적분 방정식에 대힙하여 해석적으로 적분함으로써 검근해를 유도하였다. 가상공간에서 적분 결과가 0이 되는 것을 보임으로써 적분 과정의 타당성을 보였다. 완전도체쇄기의 점근해 유도과정에 쌍적분 방정식을 이동함으로써 얻은 잇점에 대해 살펴보았다.

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ON A DISCUSSION OF NONLINEAR INTEGRAL EQUATION OF TYPE VOLTERRA-HAMMERSTEIN

  • El-Borai, M.M.;Abdou, M.A.;El-Kojok, M.M.
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제15권1호
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    • pp.1-17
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    • 2008
  • Here, we consider the existence and uniqueness solution of nonlinear integral equation of the second kind of type Volterra-Hammerstein. Also, the normality and continuity of the integral operator are discussed. A numerical method is used to obtain a system of nonlinear integral equations in position. The solution is obtained, and many applications in one, two and three dimensionals are considered.

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USING CROOKED LINES FOR THE HIGHER ACCURACY IN SYSTEM OF INTEGRAL EQUATIONS

  • Hashemiparast, S.M.;Sabzevari, M.;Fallahgoul, H.
    • Journal of applied mathematics & informatics
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    • 제29권1_2호
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    • pp.145-159
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    • 2011
  • The numerical solution to the linear and nonlinear and linear system of Fredholm and Volterra integral equations of the second kind are investigated. We have used crooked lines which includ the nodes specified by modified rationalized Haar functions. This method differs from using nominal Haar or Walsh wavelets. The accuracy of the solution is improved and the simplicity of the method of using nominal Haar functions is preserved. In this paper, the crooked lines with unknown coefficients under the specified conditions change the system of integral equations to a system of equations. By solving this system the unknowns are obtained and the crooked lines are determined. Finally, error analysis of the procedure are considered and this procedure is applied to the numerical examples, which illustrate the accuracy and simplicity of this method in comparison with the methods proposed by these authors.

입계기공의 확산성장 모델을 이용한 고온 기기의 크립균열전파 해석 (2)

  • 전재영
    • 대한기계학회논문집A
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    • 제20권4호
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    • pp.1186-1193
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    • 1996
  • The analytic solution of the stress field at creep crack in the presence of grain boundary caviation is to be obtained by solving the governing equation which was derived through the previous paper. The complex integral technique is used to slove the singular integral equation. under the help of the information about stress behaviors at the ends of integral region know by numerical solution. The resultant stress disstribution obtained shows the relaxed crack-tip singularity of $r^{1/2+\theta}$ due to the intervention of cavitation effect, otherwise, it should assumed to be $r^{1/2}$ singularity of linear elastic fracture mechanics with no cavitation.

Flapwise and non-local bending vibration of the rotating beams

  • Mohammadnejad, Mehrdad;Saffari, Hamed
    • Structural Engineering and Mechanics
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    • 제72권2호
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    • pp.229-244
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    • 2019
  • Weak form integral equations are developed to investigate the flapwise bending vibration of the rotating beams. Rayleigh and Eringen nonlocal elasticity theories are used to investigate the rotatory inertia and Size-dependency effects on the flapwise bending vibration of the rotating cantilever beams, respectively. Through repetitive integrations, the governing partial differential equations are converted into weak form integral equations. The novelty of the presented approach is the approximation of the mode shape function by a power series which converts the equations into solvable one. Substitution of the power series into weak form integral equations results in a system of linear algebraic equations. The natural frequencies are determined by calculation of the non-trivial solution for resulting system of equations. Accuracy of the proposed method is verified through several numerical examples, in which the influence of the geometry properties, rotatory inertia, rotational speed, taper ratio and size-dependency are investigated on the natural frequencies of the rotating beam. Application of the weak form integral equations has made the solution simpler and shorter in the mathematical process. Presented relations can be used to obtain a close-form solution for quick calculation of the first five natural frequencies of the beams with flapwise vibration and non-local effects. The analysis results are compared with those obtained from other available published references.

Path-Integral Solution을 이용한 랜덤동요된 조화가진력을 받는 임팩트시스템의 거동분석 (Dynamic Behaviors of an Impact System under Randomly Perturbed Harmonic Excitation by the Path-Integral Solution Procedure)

  • 마호성
    • 한국전산구조공학회논문집
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    • 제17권1호
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    • pp.83-91
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    • 2004
  • 랜덤동요된 조화가진력을 받는 임팩트시스템의 비선형거동을 개발된 반해석적절차에 의해 확률영역에서 분석하였다. 반해석적절차는 path-integral solution을 이용하여 임팩트시스템의 추계론적 미분방정식으로부터 구함으로 얻어진다. 결합확률밀도함수의 전개를 구하고 시스템의 비선형거동 특성인 혼돈거동에 대하여 분석하고 노이즈의 영향을 시간영역과 확률영역에서 알아보았다. 결과로부터 반해석적절차는 결합확률밀도함수를 통하여 임팩트시스템의 거동에 대한 정보를 제공하는 것을 알 수 있었다. 노이즈의 영향은 혼돈거동의 특성을 약화시키며 궁극적으로 사라지게 함을 알 수 있었으며 또한 혼돈거동의 특성이 상대적으로 높은 노이즈아래에서도 남아있는 것을 밝혔다. 결합확률밀도함수는 응답앙상블이 약정상과정임을 확인시켜 주었다.

A Numerical Method for the Minimum Norm Solution to the First Kind Integral Equations

  • Yun, Jae Heon
    • 충청수학회지
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    • 제6권1호
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    • pp.25-43
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    • 1993
  • This paper introduces a numerical method approximating the minimum norm solution to the first kind integral equation Kf = g with its kernel satisfying a certain property, where g belongs to the range space of K. Most of the existing expansion methods suffer from choosing a set of basis functions, whereas this method automatically provides an optimal set of basis functions approximating the minimum norm solution of Kf = g. Perturbation results and numerical experiments are also provided to analyze this method.

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