Temperature influence on the mechanical properties of CFRP laminates evaluated by DIC

Abstract Carbon fiber reinforced polymer (CFRP) composites are widely used in aerospace, marine and automotive structures, where components may experience variable thermal conditions that affect stiffness, strength and load-bearing capacity. This study evaluates the influence of temperature on the mechanical properties of CFRP laminates manufactured from Gurit EP137 prepreg and tested using a universal testing machine supported by full-field Digital Image Correlation (ARAMIS/DIC). The complete set of tensile, compressive and shear properties was determined for 20–80 °C, whereas at − 20 °C only the in-plane shear modulus G₁₂ and shear strength FSU₄₅° were obtained because frosting/icing of the chamber window and specimen surface prevented reliable DIC image registration during selected tests. Between 20 °C and 80 °C, E₁ showed an apparent increase of approximately 8.2%, while E₂ and G₁₂ decreased by approximately 34.6% and 58.5%, respectively. The tensile strength FTU₀° decreased by 28.1%, the shear strength FSU₄₅° by 41.3%, and the compressive strengths FCU₀° and FCU₉₀° by 49.4% and 43.5%, respectively. The results confirm that matrix-dominated properties are particularly sensitive to elevated temperature and provide temperature-dependent material input for subsequent numerical modelling and stability analyses of thin-walled CFRP structures.