Investigation of Surface Treatment Effects on Strain Transfer Mechanisms Between Fiber and Matrix During Curing With Self‐Sensing Fibers

To address the limited understanding of how surface treatments influence cure‐induced strain in fiber‐reinforced composites, this study investigates the strain development mechanism using self‐sensing fibers with different surface treatments. Three types of FBG self‐sensing fibers, including untreated (FBG‐N), KH550‐treated (FBG‐K), and release agent‐treated (FBG‐R), were prepared and adopted in single‐fiber composites to monitor real‐time strain evolution during curing. An analytical thermo‐chemical–mechanical coupling model was developed to quantify the effects of surface treatments on strain transfer. The experimental and analysis results reveal significant surface treatment effects on strain transfer mechanisms. KH550 treatment improved interfacial shear strength (IFSS) by 20.73% while release agent reduced IFSS by 51.96%. The cure‐induced strain marginally increases by 8.56% with KH550 treatment but significantly reduced by 31.84% with release agent due to interfacial slippage. This work provides critical insights into interfacial design for optimizing composite performance during manufacturing.