Electronic speckle pattern interferometry (ESPI) and computational modeling in the analysis of vibration modes and material parameters of polyamide‐based composites reinforced with carbon fibers

Electronic speckle pattern interferometry is a non‐contact method used to analyze the vibrational modes of mechanical structures. Due to its ability to precisely map deformations and stress in samples made of various materials, it provides a unique insight into the behavior of materials under dynamic loading. This work focuses on the application of electronic speckle pattern interferometry in investigating the vibrational characteristics of composite materials based on polyamide reinforced with carbon fibers in varying weight ratios. The carbon fibers were surface‐modified using nitric acid and silica nanoparticles to increase their surface energy and enhance adhesion to the polymer matrix. These modifications contribute to improved mechanical properties of the composite. Based on the analysis of vibrational modes, key material parameters were determined, namely, the tensile modulus of elasticity, Poisson's ratio, and shear modulus. The obtained vibrational mode results were compared with numerical simulations performed using the Finite Element Method, which allowed for validation of the measurement accuracy and a better understanding of the dynamic behavior of the composites.