Microscopic cooling deformation measurement system based on sampling moiré and its application to CFRP

Research on the performance of Carbon Fiber Reinforced Polymer (CFRP) under low-temperature conditions is significant. This study developed a novel microscopic cooling deformation measurement system based on the sampling moiré method, the system integrates the advantages of the sampling moiré method for measurements and holistic design optimization for low-temperature environments. It features a simple process, high precision, and high stability, and is suitable for various materials. The system primarily consists of a cooling chamber, antifreeze circulation device, laser confocal microscope, and temperature controller, among other components. The temperature regulation range of the cooling platform spans from −40 °C to 150 °C. This study used CFRP [0°/90°/0°] as the specimen, and the constructed system was employed to measure microscopic deformation during cooling and heating processes. The results revealed that deformation along the CFRP's longitudinal direction is minimal, whereas, in the thickness direction, the 0° layer primarily dictates the deformation behavior. The 0° layer consistently constrains the deformation of the 90° layer, and shear strain exhibits significant variations at the interface. This research presents the first application of the sampling moiré method in low-temperature deformation measurement. It elucidates the effects of varying temperatures on the interfacial mechanical properties of CFRP while demonstrating the suitability of the developed system for low-temperature microscopic deformation measurements of specimens.