KSME Journal

, Volume 4, Issue 1, pp 78–85 | Cite as

An approximate method to compute the nonlinear normal modes and bifurcation by the principle of least action

  • Chol Hui Pak
  • Young Suk Yun


An analytical procedure is presented to find approximately the nonlinear normal modes in conservative two-degree-of-freedom system by using the principle of least action and by assuming that the modal curve is straight. The results are compared with those of numerical experiments by utilizing the 4th order Runge-Kutta method, and it is found that there are good agreements between them. By utilizing this procedure, it is demnostrated to compute the normal modes which are analytically extended from the linearized modes and to find the generically or non-generically bifurcated modes which do not have any counterpart in the linear theory.

Key Words

Nonlinear Normal Mode Generic Bifurcation Non-Generic Bifurcation Modal Curve Homogeneous System Principle of Least Action 


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Copyright information

© The Korean Society of Mechanical Engineers (KSME) 1990

Authors and Affiliations

  • Chol Hui Pak
    • 1
  • Young Suk Yun
    • 1
  1. 1.Department of Mechanical EngineeringInha UniversityInchonKorea

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