Accession Number : ADP003681

Title :   Recent Advances in Reduction Methods in Non Linear Structural Dynamics,

Corporate Author : INSTITUTE OF TECHNOLOGICAL DEVELOPMENT FOR THE CHEMICAL INDUSTRY SANTA FE (ARGENTINA)

Personal Author(s) : Idelsohn,S. R. ; Cardona,A.

Report Date : 1984

Pagination or Media Count : 8

Abstract : The present paper pursues the development of a new technique of reduction that applies specially in the case of non linear dynamics. It consists in adding some derivatives of the displacements with respect to the modal amplitude parameters to the basis obtained by local model superposition. The derivatives can be taken up to various orders. It is shown in the examples that this basis is adequate in order to approximate the system's behaviour with a very large number of degrees of freedom and with a very limited number of updatings. The resulting reduced system is integrated by using the Newmark's implicit algorithm. A control strategy to determine the correct moment in which the basis vectors should be updated is proposed. Only geometrical non linearities are treated in this paper but no difficulty exist to extend the concept to material non linearity.

Descriptors :   *Structural mechanics, *Nonlinear systems, *Algorithms, *Mathematical prediction, *Dynamic response, Reduction, Degrees of freedom, Equations of motion, Computations, Differential equations, Finite element analysis, Derivatives(Mathematics)

Distribution Statement : APPROVED FOR PUBLIC RELEASE