THE NATURAL FREQUENCIES OF INPLANE STRESSED RECTANGULAR-PLATES

The stress distributions in some practical in-plane loaded plates have been obtained either directly via strain gages or indirectly from the measurement of transverse deflections or initial imperfection profiles. These stress distributions have been incorporated into a purpose-written finite difference computer program set up to evaluate the natural frequencies of the plates. A comparison has been made between these frequencies and those measured directly in the laboratory. A further comparison has been made with the natural frequencies calculated on the assumption of a uniform in-plane stress distribution. The results explain, in part, the discrepancies between theory and experiment that have been observed by previous workers.