遠心力を受ける複合材積層板の振動解析

抄録

Since composite materials are known to have high specific stiffness and strength, they have been widely used in many industrial fields, including windmill turbine blades. Such light-weight composite structures under body forces are required to study their vibration characteristics to prevent fatigue failure and noise. In this report, the effect of centrifugal forces is studied on natural frequencies of laminated composite plates as such a model of blade. The stress distribution of plates under centrifugal forces is first solved by the Ritz method, and the natural frequencies under in-plane stresses are calculated in the Ritz method by using in-plane stress distributions determined in the first problem. The numerical results obtained by the present method are compared with those from FEM. It is found that both results for the plate with various aspect ratios agree well and this validates the present calculation method. As an application of the present method, lay-up configurations of composite laminated plates are optimized for maximizing frequencies of arbitrary modes under centrifugal forces by a layerwise optimization (LO) method. The optimum lay-up configuration determined by the LO method with the present model results in higher natural frequencies than plates with typical lay-up configurations.