ABSTRACT The article deals with applications of electronic speckle pattern interferometry (ESPI) and pulsed phase termography (PPT) in the industry of composite materials. Composite materials have been widely used in various engineering components. Defects or cracks inevitably occur in components during manufacturing processes and operations. To ensure structural safety, a nondestructive testing has often been performed to detect defects or cracks in the components, in this article by using PPT. In the first case this paper has collected some information about possibilities, advantages and disadvantages of ESPI applications by nondestructive testing of composite materials and briefly introduces a damping feature of composite materials. The theory of plate vibrations allows us to determine Poisson’s ratio , Young`s modulus E and shear modulus G in the case of isotropic composite materials and orthotropic materials from the measured resonant frequencies. We are able to analyse the damping behaviour of various types of composite materials from measured mode shapes. The paper also describes a unique approach to the application of the PPT in a contactless detection of hidden flaws in glass fibre reinforced laminates. It consists of the arrangement of the raw thermograms set, acquired during the termovision inspection of the thermally disturbed laminate surface, into a single thermal image, which contains the whole time history of its cooling-down process. This concentrated thermal image is consequently extended by means of two-dimensional discrete wavelet transformation and upsampled as one-dimensional multichanel discrete thermal signal, which is then analysed in the frequency domain obtained by the one-dimensional fast discrete Fourier transformation.
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