Calculating resonance frequencies of perforated panels

Previous analyses of perforated panels have concentrated on the calculation of elastic properties. These properties are commonly applied to the stress analysis of tubesheet designs for large boilers. Two theoretical analyses, a finite element analysis (F.E.A.) and an experimental study are compared, where applicable, for 13 perforates to determine the most accurate method for determining the effective resonance frequency. Parameters defining the geometry of the holes in a perforation array are introduced, as well as the ratio of the modal resonance frequencies of a perforate to those of a corresponding solid panel, termed the effective resonance frequency. A cubic function is derived to fit the F.E.A. results, and so provide a convenient way of determining the effective resonance frequency of panels with a wide range of perforation geometries. (C) 1996 Academic Press Limited.