Full-Field Microscale Strain Measurement of Carbon Fiber Reinforced Plastic Using 2-Pixel Sampling Moiré

Microscale strain distributions are essential parameters for evaluating the mechanical properties and instability behaviors of composite materials. In this study, a recently-developed reconstructed multiplication moiré method from 2-pixel sampling moiré fringes was used to investigate the microscale deformation performance of a carbon fiber reinforced plastic (CFRP) specimen. This method enables wide field of view and high displacement and strain sensitivities for deformation measurement of CFRP. A microgrid as the deformation carrier was fabricated on CFRP by ultraviolet nanoimprint lithography. The in situ full-field distributions of two-dimensional (2D) displacements, normal strains and shear strains of CFRP were quantitatively measured at different three-point bending loads under a laser microscope. The deformation distribution features of CFRP were analyzed, which is helpful to understand its potential damage mechanism.