Mechanical performance of 2D‐C/SiC I‐beams under different loading modes

Abstract Application of carbon fiber‐reinforced silicon carbide (C/SiC) composites in aerospace structures is increasing due to their high specific strength and thermal resistance. However, limited data are reported on the flexural performance of C/SiC structural members under complex loading modes. This study investigates the mechanical behavior of 2D‐C/SiC I‐beams under plane‐bending, skew‐bending, and bending‐twist through experiments and finite element (FE) simulations. Fracture loads of 9260, 5782, and 7831 N were recorded for plane bending, skew bending, and bending‐twist, respectively. Delamination was the dominant failure mode in all cases, with rupture occurring at the bottom flange. Damage initiation and progression were monitored using strain gauges, and infrared thermal wave imaging confirmed the onset and progression. FE simulations incorporating nonlinear constitutive behavior and Hoffman failure criterion reproduced the strain response and ultimate loads with small deviations (7.6% in plane bending, 4.2% in bending‐twist), and a larger error in skew‐bending (13%) due to stress interactions. While the study provides validated experimental and numerical insights, it was limited by a small specimen set and a simplified calculation procedure. Future work should refine FE models to include progressive damage and extend the study to cyclic, thermal, and fatigue loadings for aerospace design.