OPTIMAL LOCATIONS OF POINT SUPPORTS IN LAMINATED RECTANGULAR-PLATES FOR MAXIMUM FUNDAMENTAL-FREQUENCY

This paper investigates the optimal locations of internal point suppor ts in a symmetric crossply laminated rectangular plate for maximum fun damental frequency of vibration. The method used for solving this opti mization problem involves the Rayleigh-Ritz method for the vibration a nalysis and the simplex method of Nelder and Mead for the iterative se arch of the optimum support locations. Being a continuum method, the R ayleigh-Ritz method allows easy handling of the changing point support locations during the optimization search. Rectangular plates of vario us boundary conditions, aspect ratios, composed of different numbers o f layers, and with one, two and three internal point supports are anal ysed. The interesting results on the optimal locations of the point su pports showed that (a) there are multiple solutions; (b) the locations are dependent on both the plate aspect ratios and the number of layer s (c) the fundamental frequency may be raised significantly with appro priate positioning of the point supports.