Inverse Evaluation of Material Constants for Composite Plates by Optical Interferometry Method

Abstract

Electronic speckle pattern interferometry (ESPI) is a powerful tool for the full eld, noncontact, and real-time measurement method of surface displacements for deformed bodies. As compared with the conventional lm recording and optical reconstruction procedures used for holographic interferometry, the interferometric fringes of ESPI are produced instantlyby a video recording system. In this study, the amplitude uctuation ESPI (AF-ESPI) optical system is used for measuring the resonant frequencies and mode shapes of vibrating composite plates. By makinguse of the resonant frequencies for free plates obtainedexperimentally,an inverse evaluationfor the material constants is developed using the Rayleigh-Ritz technique and the Simplex method for function minimization. Finally, nite element calculation is used to construct the mode shapes from the obtained material constants by inverse evaluation, and the results are compared with the experimental observations. The experimental method based on optical AF-ESPI setup and the inverse algorithms proposed might become a reliable and self-consistent methodology for evaluating material constants of composite plates. Nomenclature A= vibration amplitude D i j = laminate bending stiffness I A = object light intensity I B = reference light intensity w = transverse displacement µ = angle between object light and observation directioņ = wavelength of laser ½ = mass density ¿ = charge-coupled device refreshing time Á = phase difference between object and reference light ! = vibration frequency

Identification of material properties of composite materials using nondestructive vibrational evaluation approaches: A review

“…The application of Rayleigh-Ritz technique for forward computation of natural frequencies in the study of elastic properties determination can be seen in [57,63,65,67,68,[101][102][103][104][105]. Most of the investigations are done on thin rectangular orthotropic plates [57, 63, 101-103, 105, 106], followed by thin rectangular laminated plates [65,67] and thick rectangular Sandwich plates [68,104] with combinations of free-clamped edges [57,63], free edges [101][102][103][104][105][106], and elastically-restrained edges [65,67,68].…”

Inverse Evaluation of Material Constants for Piezoceramics by Out-of-Plane Vibration

“…This inverse evaluation methodology, by the Rayleigh-Ritz method and the Simplex algorithm, has been employed for the composite plate and discussed in detail by Ma and Lin. 22 By means of Eq. (21), the inverse evaluation method for orthotropic plates can be applied to the piezoceramic rectangular plates.…”

Identification of Material Properties of Composite Materials

“…To obtain more accurate and reliable results, it is necessary to use more efficient searching methods. Thus, an identification method combining experiment design, the response-surface function, and finite element analysis has been used for the elastic constants of composite laminates Ma et al 1999). The works of Cunha, Maletta, Hwang, and Lee clearly show the potential of genetic algorithms (GAs) for the procedure of identifying material properties (Cunha et al 1997;Hwang et al 2006;Lee et al 2006).…”