Node Sampling for Nonlinear Vibration Analysis of Structures with Intermittent Contact

摘要

In this paper, a node sampling methodology for nonlinear vibration problems of elastic structures involvingnintermittent contact is proposed. Of particular interest is a vibration problem of platelike elastic structures with ancrack, with a large number of degrees of freedom involved on the crack surfaces. Because of the localized nature ofnsuch nonlinearity, the number of degrees of freedom on the surfaces greatly affects the computational time of thenanalysis.Therefore, reducing the number of degrees of freedomon the crack surfaceswithout significantly sacrificingnthe accuracy of the results is a critical issue for conducting vibration analysis of such structures in a reasonablenamount of time. The focus is placed on the development of an efficient algorithm to select a set of nodes on the cracknsurfaces, where nonlinear boundary conditions are imposed. The method is developed, based on a procedure fornselectingmaster degrees of freedomforGuyan reduction. The accuracy, efficiency, and optimality of themethod arendiscussed in detail and compared with those aspects of previous methods. The advantages of the new method arendemonstrated in terms of the accuracy of the frequency response and the resonant frequencies.