Abstract：By using the large commercial finite element software NASTRAN, a method that the elastic parameters of a 2.5D C/SiC composite plate are determined by parameter identification based on the modal test data is proposed in this paper. An optimization problem is formulated with the model updating technique in which the objective function is defined as the sum of squares of the discrepancy between measured and calculate modal frequencies, the initial value of the elastic parameters are obtained by adopting stiffness averaging method which makes full use of the prior information of the material parameters. Finally, the accurate elastic parameters of the composite plate are identified through a iteration process by using sensitivity analysis method. The accuracy of the first 1-4 modal frequencies of C/SiC composite plate are significantly improved by identification, while the predictive accuracy of the 5-8 modal frequencies can also be guaranteed. Results show that the proposed method can accurately identify the 2.5D C/SiC composite elastic parameters, and the method proposed in this paper can provide effective references for dynamic design and equivalent modeling of C/SiC composite.
2014, Vol. 33 
