Validating the efficacy of deformation distribution measurement in CFRP laminates during three-point bending using the sampling moiré method

The damage behavior of carbon fiber reinforced plastics (CFRP) is highly complex due to the overlapping of various damage forms. To elucidate this deformation behavior, it is crucial to evaluate the micro-scale deformation distribution before the occurrence of each type of damage. The sampling Moiré method has been recognized as an effective experimental technique for analyzing such deformation behavior. In this study, we used the sampling Moiré method to calculate the micro-displacement distributions of [±45°]4s CFRP laminates during a three-point bending test under microscopic observation. Additionally, a finite element model was created under the same conditions to compute the displacement distribution using the finite element method (FEM). A comparison of the displacement distributions obtained from both experimental and simulation methods confirmed their consistency. The simulation results also revealed the difference in CFRP displacement distribution characteristics with and without interlayer resin, which manifested that the presence of a resin layer between the CFRP layers induced a distinctive wave displacement distribution when subjected to a three-point bending load.