IN this paper, a system of micromechanical experiments is established combining microscopic moire interferometry of high spatial resolution with optical microscope. Under uniaxial tensile loading, the quantitative local-field of interlaminar displacements of the AS4/PEEK laminates has been measured. The pictures of in-situ interlaminar damage initiation and growth process have been simultaneously collected by the experimental system continuously. The major characteristic of interlaminar damage of the laminate under tensile loading is the group of matrix cracks in 90/90 plies, which are formed due to fiber- matrix interface debondings, and the number of cracks increases when the load increases. The u fields of interlaminar displacement of a matrix crack under certain loads are gained using the microscopic moire interferometry.
Different software codes useful in fringe pattern analysis are described. The problems of achieving, digitizing and analyzing are briefly discussed with reference to a new software code, completely written in our laboratories. Some applications of numerical processing to holographic interferometric fringe patterns are described.
The application of the holographic moiré technique to the characterization of graphite-peek specimens is shown. With reference to previous papers, advantages and disadvantages of the technique are pointed out. A grid method combined with microscopy is then used to characterize some composite laminates both to fatigue and static loads. Results of different tests are shown and discussed.