A Review on Resistance-Based Self-Sensing of Carbon Fiber-Reinforced Polymer Subjected to Loads

Abstract

Carbon fiber-reinforced polymer (CFRP) composites exhibit remarkable self-sensing capabilities, where electrical resistance varies with externally applied loads, enabling their application in structural health monitoring (SHM) without additional devices. This review comprehensively analyzes the conductive mechanisms of CFRP, resistance variations under diverse loading conditions, and the electrical responses induced by strain and damage. It also explores optimization strategies for enhancing self-sensing capabilities and theoretical resistance models. In unidirectional CFRP, resistance changes primarily due to fiber-to-fiber contact variations, making it highly strain-sensitive. Multidimensional CFRP can detect interlayer cracks, impact damage, and multiaxial stresses. Adding conductive fillers below the percolation threshold enhances strain sensitivity, while fiber surface modifications, optimized fiber volume fractions, and improved manufacturing processes further enhance self-sensing performance. Practical applications demonstrate that surface cracks and internal damages can be monitored via electrical resistance measurements in CFRP structures. By integrating current knowledge and highlighting future research directions, this review provides valuable insights into optimizing CFRP's self-sensing properties and expanding its use in advanced SHM systems.