Electromechanical behavior and damage index system of 3D carbon fiber angle-interlock woven composites with FEA and data processing tools

Abstract

The relationship between structural damage and electrical resistance change of carbon fiber reinforced composites is important to structural health monitoring. Here, we investigated the electromechanical behavior and damage index system for identification of various damage types in 3D angle-interlock woven composites under tensile loading in the warp direction. The mechanism of electrical resistance change was explored by combining current injected from both ends (Electrical current is in the plane of the laminate and goes through the entire cross section of the specimen) and current injected diagonally (Direction of electrical current between the in-plane direction and the through-thickness direction). A finite element model was established to analyze the electric potential distribution and tensile damage evolution process of composites. We found current injected from both ends can only detect with yarn damage and current injected diagonally can detect with matrix cracks, interface cracking and yarn damage. Based on the electrical resistance data of current injected diagonally, we used principal component analysis and K-means clustering methods to establish a damage index system to reflect the damage accumulation degree of different damage modes. The finite element analyses verified the rationality of the damage index system.