9bb27b81-7939-4666-81a2-d5dc2ebc9e2a20250707083648809wseas:wseasmdt@crossref.orgMDT DepositInternational Journal of Chemical Engineering and Materials2945-051910.37394/232031https://wseas.com/journals/cem/32620253262025410.37394/232031.2025.4https://wseas.com/journals/cem/2025.phpAbelashviliNodarFaculty of Informatics and Control system Georgian Technical University Kostava 77, Tbilisi GEORGIAOtkhozoriaNonaFaculty of Informatics and Control system Georgian Technical University Kostava 77, Tbilisi GEORGIAJaparashviliSopioFaculty of Informatics and Control system Georgian Technical University Kostava 77, Tbilisi GEORGIAIn the current stage of technical and technological advancement, the widespread use of composite materials across various fields is driven by their many positive properties, including the stability of their mechanical, physical, and chemical parameters. These properties significantly determine product quality. Given the advantageous characteristics of composite materials, they are suitable for use in interlaboratory qualification tests, where strict requirements are placed on the stability and durability of test samples. Key parameters for testing are determined at the initial stage of control sample preparation. These include the specifics of the studied object, test methods, testing equipment, data analysis methods, the accuracy of obtained results, repeatability, reliability, and reproducibility. Based on multiple trials, the testing laboratory assigns the control parameter value in accordance with certifying organizations’ and/or ISO 13528:2022 requirements. Typically, quality control tests for composite materials are performed at various stages of the product's life cycle, from manufacturer to consumer, under conditions with high variability in operators, environmental factors, equipment, and testing techniques. Therefore, ensuring consistent results across different laboratories is essential. The aim of this study was to assess the compliance of interlaboratory testing by measuring mechanical properties (compression, tension, and bending) using a high-accuracy universal testing machine, the Zwick Roell Z100. The control samples were manufactured from epoxy pre-impregnated fiberglass fabric, recommended as reference material for qualification trials in interlaboratory testing.77202577202529335https://wseas.com/journals/cem/2025/a10cem-005(2025).pdf10.37394/232031.2025.4.5https://wseas.com/journals/cem/2025/a10cem-005(2025).pdf10.31435/rsglobal_conf/30062021/7621N. Abelashvili and E. Didenko, "Determination of the assigned value by the parameter of the test control sample using a coordinate measuring machine," in *Proc. XXX Int. Sci. Pract. Conf.: Int. Trends in Sci. and Technol.*, Warsaw, Poland, Jun. 2021, p. 6. S. Bouhouche, R. Drai, and J. Bast, "Extended Kalman Filter and Markov Chain Monte Carlo Methods for Uncertainty Estimation. Application to X-Ray Fluorescence Machine Calibration and Metal Testing," WSEAS Trans. Inf. Sci. Appl., vol. 14, pp. 227–238, 2017. A. Varvani-Farahani, *Composite Materials: Characterization, Fabrication and Application – Research Challenges and Directions*. Dordrecht, Netherlands: Springer Science + Business Media B.V., 2009. 10.1006/jcis.2002.8332J. G. Iglesias, J. Gonzalez-Benito, A. J. Aznar, J. Bravo, and J. Baselga, "Effect of glass fiber surface treatments on mechanical strength of epoxy-based composite materials," *J. Colloid Interface Sci.*, vol. 251, pp. 251– 260, Jun. 2002. 10.46299/j.isjea.20240302.03T. Menabde, N. Otkhozoria, and V. Otkhozoria, "Use of the theory of measurement uncertainty in procedures for data processing and results obtained by checking-calibration gas flow meters," *Int. Sci. J. Eng. Agric.*, vol. 3, no. 2, pp. 40–46, 2024. [Online]. Available: https://doi.org/10.46299/j.isjea.20240302.03