Metric entropy and digital image correlation in deformation dynamics analysis of fibre glass reinforced composite under uniaxial tension

•Kolmogorov-Sinai metric entropy could assess composite mechanical properties.•DIC confirmed the correctness of K-S metric entropy approach.•Drop of K-S metric entropy determines the material tensile strength. This paper proposes a combined method for the mechanical properties assessment of composite materials based on the analysis of the internal dynamics of raw data from uniaxial tensile tests. Determination of the Kolmogorov-Sinai (K-S) metric entropy from the recorded data enables to find the tensile strength of materials. The correctness of the methodology proposed was verified by the full filed DIC measurements. Therefore, the main aim of this research was to apply independent measurement tools in the analysis of the non-linear dynamics supported by their mutual validation. The experimental program carried out on the glass fibre-based thermoplastic Elium acrylic composite and E752 Carbon Fiber Reinforced Epoxy (CFRE) composite confirmed the high suitability of the presented methodology in ultimate tensile stress identification, and thus, its great applicability potential in many aspects of the contemporary engineering.