| Abstract: | Lord Rayleigh proposed his now classical method (based on a one-term deflection function) in 1870. On the other hand, he suggested in 1894 the possibility of optimizing the eigenvalues (natural frequencies or buckling loads) by minimizing them with respect to an exponential parameter contained in the coordinate function. This optimization approach has become increasingly popular in the last decade and it has been extended to other variational methods and bounding techniques. The present paper reviews recent developments in this area which consists, essentially, in a nonlinear optimization process of the coordinate functions in a global sense. The technique is applicable in a large variety of applied mechanics problems of considerable interest to ocean engineers dealing with the analysis of mechanical systems. |
