The Effect of Pre‐Cyclic Thermal Loads on the Buckling Performance of Glass Fiber‐Reinforced Polymer Composites Without Post‐Curing Treatment: Experimental and Numerical Investigation

ABSTRACT This study examines the impact of pre‐cyclic thermal loading on the buckling performance of S2 glass fiber‐reinforced polymer (GFRP) composites fabricated without post‐curing treatment. Specimens were subjected to 500 thermal cycles between −30°C and +80°C to simulate demanding aerospace conditions. Mechanical characterization was performed through tensile, shear, and buckling tests, and the results were compared with those of non‐cycled counterparts. Finite element simulations incorporating Hashin's damage criteria were used to further elucidate the effects of thermal cycling. The findings reveal that pre‐cyclic thermal exposure leads to notable improvements in in‐plane material properties and critical buckling load, as well as enhanced displacement at buckling failure. Damage analysis indicates that thermal cycling strengthens fiber‐matrix bonding while reducing delamination and micro‐buckling. These results suggest that controlled thermal cycling can act as a quasi‐post‐curing process and offer a practical approach to enhance the durability and performance of GFRP composites in aerospace applications.