Evaluation of Structure Design on Strengthening and Toughening Behaviors of Plain‐Woven Fabric‐Reinforced <scp>PEEK</scp> Composites

ABSTRACT This study first enhances fiber‐matrix interfacial bonding through a three‐step modification approaches: high‐temperature heat treatment, liquid‐phase oxidation, and polyamide‐imide (PAI) sizing. By integrating these interfacial improvements with structural parameters (fiber content, stacking angle, and sequences), this study systematically investigates the interface‐structure synergistic reinforcement mechanisms in plain‐woven carbon fiber reinforced polymer composites (CFRP). Experimental results reveal three key trends: (1) under fixed stacking configurations, tensile strength increases with fiber content, peaking at 669.97 MPa (60 wt%, [0°/0°/45°] 5s ); (2) impact strength depends more on stacking angles/sequences than fiber content, achieving 103.61 kJ/m 2 with [45°/45°] 7s laminates at 50 wt%; (3) bending strength inversely correlates with fiber content, reaching 885.21 MPa (50 wt%, [0°/0°] 7s ). Scanning electron microscopy (SEM) characterization and mechanical testing identify governing mechanisms: fiber content governs tensile performance through load distribution efficiency; stacking angle enhances toughness via fiber reorientation mechanisms; stacking sequences optimizes bending behavior by suppressing delamination failure. These findings establish actionable guidelines for designing high‐performance CFRP components in the aerospace and automotive industries.