Efficient analysis of characteristic responses to curing behavior using FBG sensors for residual strain controlling in CFRP laminates

Abstract

Fiber Bragg Grating (FBG) in-situ monitoring systems have become an effective tool for assisting with the high-precision molding and process optimization of carbon fiber-reinforced polymers (CFRP). This study aims to explore the underlying mechanisms by which FBG sensing signals characterize the curing behavior of CFRP. Initially, based on in-situ/non in-situ testing methods, the characteristic responsiveness of FBG sensing signals to the curing behavior of CFRP was explored. Furthermore, the feature response amplitude was used to evaluate the feature responsiveness of embedding setups (packaging structure and embedding techniques) to phase transitions. It was found that non-uniform adhesion and consolidation affected the sensor’s representation of curing shrinkage. Finally, using high characteristic response FBG sensors, the process optimal strategy for CFRP was explored. The proposed method for analyzing the characteristic response of FBG sensing signals establishes and validates the relationship between CFRP curing behaviors and signal points, as well as stage-specific amplitude changes. This research serves as a fundamental basis for accurately characterizing CFRP curing behaviors and enhancing high-precision forming process design.