Nondestructive Method to Determine Critical Loads for Rods, Plates and Shells Made of Composite Materials.

One of the variants of the resonance method is considered which permits determining and carrying capacity of thin-walled structures such as rods, plates and shells using a functional dependence between natural oscillation frequency, wave formation parameters and the critical load. The indicated functional relationship of parameters occurs for any materials irrespective of their elastic characteristics, degree of anisotropy and type of loads. Data from the test results performed on plates and cylindrical shells made of glass-reinforced plastic of orthogonal reinforcement are compared.