On the elastic characterization of composite plates with vibration data

This paper takes a global look at a method of obtaining the elastic constants of the material of a rectangular plate sample by explicitly inputting the geometrical shapes and frequencies of a sufficient number of experimental vibration modes into a computational procedure that essentially compares experimental frequencies with analytical predictions. There are many aspects of this method that have important bearing on accuracy, ease of use and computational economy. The issues that arise include vibration representation functions, selection of experimental mode shapes and frequencies for analysis, goodness of experimental data, frequency sensitivity of the elastic constants, influence of diagonal modes where relevant, plate thickness, plate aspect ratio, material orthotropy ratio and orientation of reinforcing fibers in laminate composites. Whereas some of these factors have been discussed separately in other works, this paper attempts bring the method completely into focus in one place, with an examination of all the factors believed to influence the efficiency of the method.