Thermo-mechanical characterization of phenolic woven composite laminates for use in fire/blast-prone aircraft baggage structures

Abstract

This paper experimentally investigates the thermal and mechanical performance of woven phenolic laminates reinforced with carbon (PF-CFRP), glass (PF-GFRP), basalt (PF-BFRP), and Kevlar (PF-KFRP), aiming to evaluate their suitability for aircraft baggage structures under fire and blast loads. Phenolic resin cured under single-stage high-temperature conditions (PF100) demonstrated a superior glass transition temperature of 150.0°C, tensile modulus of 2.61 GPa, and tensile strength of 32.51 MPa. Thermogravimetric analysis revealed that PF-CFRP retained 87.9% mass at 800°C under nitrogen, while PF-BFRP retained the highest mass in air (79.1%), followed by PF-GFRP (66.3%). PF-KFRP exhibited poor thermal stability (47.7%), even lower than the neat resin (58.9%) under nitrogen. PF-CFRP exhibited the highest modulus and strength, with 68.50 GPa and 776.78 MPa, respectively, and an in-plane shear strength of 110.46 MPa. PF-BFRP showed the highest flexural strength of 362.93 MPa, excellent tensile strength of 587.63 MPa, and improved bending failure strain of 2.25%. PF-GFRP exhibited moderate mechanical performance, with tensile and flexural strengths of 224.11 MPa and 292.59 MPa, respectively, with consistent shear performance. PF-KFRP exhibited the highest failure strain (2.76% in tension), but weak interfacial bonding. Scanning electron microscopy revealed distinctive failure modes, including fiber breakage, pull-out, delamination, and matrix cracking. Radar plots were used for comparative visualization, identifying PF-BFRP as optimal for blast/fire resilience and PF-CFRP for stiffness-critical zones. Overall, the study highlights the potential of basalt-phenolic composites and recommends functionally graded hybrid composites as next-generation materials for aircraft baggage structures under combined mechanical and thermal conditions.