Post-Fire Response of the Composite Facesheet Used in the Main Rotor Blades: A Case Study

This chapter delves into the post-fire response of composite facesheets used in the main rotor blades of helicopters. It examines the changes in surface morphology and composition, revealing a rougher texture and elemental variations due to fire exposure. The study highlights significant reductions in tensile strength and interfacial bonding, with a notable 30% decrease in tensile strength and a 35% decline in interlaminar shear strength (ILSS). The mechanical properties, including tensile, flexural, and ILSS, are thoroughly analyzed, showing the detrimental effects of fire on the material's load-bearing capacity. Dynamic Mechanical Analysis (DMA) results indicate a drastic drop in storage modulus, loss modulus, and tan delta with increased flame exposure, along with a shift in glass transition temperature (Tg). The chapter concludes with insights into the structural weakening and degradation of interfacial bonding caused by fire exposure, providing valuable data for improving the fire resistance of composite materials in aerospace applications.