MOIRE INTERFEROMETRY FOR COMPOSITE AND SMART MATERIALS

摘要

High sensitivity Moire interferometry is a coherent light optical technique that features whole field, two-dimensional, real time, and in-plane deformation measurements. The high resolution and high contrast of the fringe patterns enable the observation and analysis in both millimeter and micrometer scales. This paper reports a study on characterization of interface in brittle matrix composite using Moire interferometry. Progressive matrix cracking and interface debonding was recorded, and an interfacial zone of about 50 μm thick carrying large shear deformation was observed. The parameters that were directly measured in laser Moire tests included fiber deformation, matrix deformation, fiber bridging stress, interface slip, interface debonding length, and matrix crack opening. The quantitative fringe analysis was thereafter carried out to determine the interface shear stress distributions by equilibrium as well as interface fracture energy release rate by compliance method. Because of its high sensitivity and high resolution, Moire interferometry is also suitable for the studies of shape memory alloys and different matrix composites.