Study On Structural Health Monitoring And Management Technology Of Fiber Reinforced Composites

Aircraft health monitoring and management technology is a technology having the ability of making appropriate decisions in both strategic and tactic levels based on aircraft fault diagnosis,fault prognostics information,logistics information and operational demand in order to optimize the efficiency of operation.The focus of this technology is to monitor and manage the health state of the aircraft through the use of intelligent models and algorithms and the monitoring capabilities of various advanced sensors.It covers many functions such as fault detection isolation,performance monitoring,residual life prediction,fault reporting selectively,decision supporting,and performance degradation trend tracking.The aircraft structure is the support platform developed by all kinds of aircraft,which is one of the main functional subsystems of the aircraft.Nowadays,advanced composite materials have been widely used in the structure of aircrafts,and the research on the health management technology of the aircraft composite structure has become an important part of the structure health monitoring and management technology of the aircraft.This paper applies theory and experiment to study the health monitoring and management technology of fiber reinforced composite materials structure based on model.In this paper,the cumulative damage model of composites proposed by Mao and Mahadevan^[49]is used to establish the relationship between the structural stiffness and the accumulative damage in the fatigue life of the fiber reinforced composites,which can accurately describe the rapid growth of the material in the early and final stages of fatigue life.At the same time,fatigue tests were carried out on unidirectional laminates and braided laminates of fiber reinforced composites.The experimental data are in good agreement with the model.Secondly,the composite matrix crack model proposed by Gudmundson and Zang^[58],the composite delamination/debonding and the fiber fracture model proposed by Shahid and Chang^[60],were used to study the fatigue behavior of the fiber-reinforced composites,including matrix cracking,delamination/debonding,Three progressive cumulative damage stages were analyzed and judged based on the experimental data.Finally,the system of fiber reinforced composite structure health monitoring and management is established by using fuzzy logic theory,and the function of health management and feedback management based on the real-time health status of composite structure is realized.