ABSTRACT
Details are presented of a series of vibration tests on pultruded GRP clamped circular plates with central circular cut-outs to determine their first six natural frequencies and mode shapes. The Nastran FE software was used to compute the same frequencies and mode shapes, assuming that the plate could be modelled as a homogeneous material with rectangular orthotropic elastic properties. In general, good agreement was obtained between the experimental and computed frequencies and mode shapes. Thus, further evidence has been provided to support the assumption that pultruded GRP plate may, for the purposes of predicting its vibration response, be idealised as a homogeneous rectangular orthotropic material even when the principal material and geometric axes of symmetry do not coincide.
