Testing of fibers reinforced composite vessel by fringes projection and speckle shear interferometry

Fringes projection and speckle shear interferometry are used for testing of subjected to cycling loading (pressure) composite vessel. As the sensitivity of the applied methods could vary in broad limits in comparison with the other interferometric techniques, the inspection is realized in a wide dynamic range. Two spacing phase stepping fringes projection interferometry is applied for absolute coordinate measurement. Derivatives of in-plane and out-of-the-plane components of the displacement vector over the object surface are obtained by lateral speckle shear interferometry in static loading (pressure). Non-linear mechanical response and fatigue of composite material are clearly detected after cyclic sinusoidal loading by macro measurement using lateral speckle shear interferometry. Fringes projection and speckle-shear interferometry are suitable for shape and normal displacements measurements in a wider dynamic range. The other advantage of the shown methods is connected with the possibility to realize compact and portable devices for in-situ inspection of investigated objects - machine parts and constructions.