Sensitivity of non-destructive technique for determination of material properties in reinforced laminated composite plate based on vibration response

Abstract

The paper presents a sensitivity analysis of the non-destructive numerical-experimental method for the identification of the elastic properties in laminated composite plate. The identification was performed on a laminated carbon fibre composite plate with laminate stacking sequence 0o/90o. The method is based on comparing natural frequencies between physical experiment and numerical results obtained by using response surface. Minimizing the error functional between the numerical and experimental data of vibration responses, the identification of materials properties can be performed. When solving the identification problem, it is recommended to take all experimentally obtained frequencies into the error functional. At the same time, different amounts of natural frequencies used for identification in the error functional show various values of material properties. Depending on the amount of frequencies in the error functional, different values of the elastic properties can be obtained. Eleven combinations of frequencies were used for identification of elastic properties. The percentage difference between experimentally measured and numerically calculated frequencies with various values of obtained elastic constants do not exceed 2.4%. Despite different values of elastic constants, small percentage difference shows good agreement between experimentally measured and numerically calculated frequencies. It can be seen that elastic constants obtained for the composite plate are fairly accurate in each case and can be used for modelling composite structures.