• 제목/요약/키워드: hamiltonian

검색결과 270건 처리시간 0.023초

해밀토니안의 시간 불연속 변분적분기를 이용한 2차원 탄소성 응력파 해석 (Analysis of 2-Dimensional Elasto-Plastic Stress by a Time-Discontinuous Variational Integrator of Hamiltonian)

  • 조상순;허훈;박광춘
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 2008년도 추계학술대회 논문집
    • /
    • pp.263-266
    • /
    • 2008
  • This paper is concerned with the analysis of elasto-plastic stress waves in a mode I semi-infinite cracked solid subjected to Heaviside pulse load. This study adopts a time-discontinuous variational integrator based on Hamiltonian in order to reduce the numerical dispersive and dissipative errors. This also utilizes an integration scheme of the constitutive model with 2nd-order accuracy which is formulated on the strain space for a rate and temperature dependent material model. Finite element analyses of elasto-plastic stress waves are carried out in order to compare the accuracy between a conventional Galerkin method and the time- discontinuous variational integrator.

  • PDF

On the large amplitude free vibrations of axially loaded Euler-Bernoulli beams

  • Bayat, Mahmoud;Pakar, Iman;Bayat, Mahdi
    • Steel and Composite Structures
    • /
    • 제14권1호
    • /
    • pp.73-83
    • /
    • 2013
  • In this paper Hamiltonian Approach (HA) have been used to analysis the nonlinear free vibration of Simply-Supported (S-S) and for the Clamped-Clamped (C-C) Euler-Bernoulli beams fixed at one end subjected to the axial loads. First we used Galerkin's method to obtain an ordinary differential equation from the governing nonlinear partial differential equation. The effect of different parameter such as variation of amplitude to the obtained on the non-linear frequency is considered. Comparison of HA with Runge-Kutta 4th leads to highly accurate solutions. It is predicted that Hamiltonian Approach can be applied easily for nonlinear problems in engineering.

Structural health monitoring through nonlinear frequency-based approaches for conservative vibratory systems

  • Bayat, M.;Pakar, I.;Ahmadi, H.R.;Cao, M.;Alavi, A.H.
    • Structural Engineering and Mechanics
    • /
    • 제73권3호
    • /
    • pp.331-337
    • /
    • 2020
  • This paper proposes a new approximate analytical solution for highly nonlinear vibration of mechanical systems called Hamiltonian Approach (HA) that can be widely use for structural health monitoring systems. The complete procedure of the HA approach is studied, and the precise application of the presented approach is surveyed by two familiar nonlinear partial differential problems. The nonlinear frequency of the considered systems is obtained. The results of the HA are verified with the numerical solution using Runge-Kutta's [RK] algorithm. It is established the only one iteration of the HA leads us to the high accurateness of the solution.

Rural Postman 문제에서 헤밀토니안 그래프 변환에 의한 유전자 알고리즘 해법 (A Genetic Algorithm Using Hamiltonian Graph for Rural Postman Problem)

  • 강명주;한치근
    • 대한산업공학회지
    • /
    • 제23권4호
    • /
    • pp.709-717
    • /
    • 1997
  • For an undirected graph G=(V, E), the Rural Postman Problem (RPP) is a problem that finds a minimum cost tour that must pass edges in E'($\subseteq$ E) at least once. RPP, such as Traveling Salesman Problem (TSP), is known as an NP. Complete problem. In the previous study of RPP, he structure of the chromosome is constructed by E' and the direction of the edge. Hence, the larger the size of IE' I is, the larger the size of the chromosome and the size of the solution space are. In this paper, we transform the RPP into a Hamiltonian graph and use a genetic algorithm to solve the transformed problem using restructured chromosomes. In the simulations, we analyze our method and the previous study. From the simulation results, it is found that the results of the proposed method is better than those of the previous method and the proposed method also obtains the near optimal solution in earlier generations than the previous study.

  • PDF