Electromechanical-Mode Coupling Model and Failure Prediction of CFRP under Three-Point Bending

Ronghua Zhang,Lifu Zhang,Wuliang Yin,Hongying Fang

doi:10.3390/electronics10162007

Abstract

Carbon fiber reinforced polymer materials (CFRP) cause CFRP to bend or fail when subjected to external loads or impacts. In the case of static three-point bending, using the conductive properties of the carbon fiber inside the CFRP, the overall damage detection and failure prediction can be carried out by electromagnetic methods. The eddy current coil is used to realize real-time monitoring of damage, and the measured voltage value can be mapped to obtain the load of the sample. This paper conducts theoretical analysis and experimental verification, and obtains the relationship between CFRP stress damage and spatial conductivity change, and proposes a CFRP electromechanical coupling model under quasistatic three-point bending. Combined with the theory of electrically ineffective length, the CFRP three-point bending electromechanical coupling model was revised. Experimental results prove that the revised model can describe the load-conductivity change trend of three-dimensional braided CFRP more accurately, which provides a theoretical basis for monitoring the structural health of CFRP through electromagnetic methods.

Highlights

Carbon fiber reinforced polymer materials (CFRP) have been widely used in industrial fields, such as aerospace, military manufacturing, and transportation [1]
Composite carbon fibers mainly bear loads and resist material deformation and damage caused by external forces
With the wide application of carbon fiber reinforced polymer materials (CFRP) in aerospace, industrial, civil life, etc., composite materials show less damage during use, which is difficult to see with the naked eye

Summary

Introduction

Carbon fiber reinforced polymer materials (CFRP) have been widely used in industrial fields, such as aerospace, military manufacturing, and transportation [1]. Through the mechanical simulation of 3DAWF of different structures, the mechanical simulation results are brought into the model, and the theoretical overall change trend is obtained, and a quasi-static bending test is performed. In order to accurately predict the load of the sample, this paper proposes an FBC electromechanical coupling model of CFRP under three-point bending. The FBC model, combined with the principle of electrical ineffective length, effectively describes the physical process of fiber fracture and reconnection, and can more accurately predict the load-conductivity change trend of CFRP. Under the condition that the structural parts are known to bear the maximum load, the conductivity model is combined with the eddy current detection technology to perform full-cycle online health monitoring of the sample structure to realize the prediction of the remaining life of the structural parts

Conductivity Change Model of CFRP under Three-Point Bending

Experimental Materials

Three‐Point Bending Solid Mechanics Part