Research On Damage Monitoring Method Based On Information Fusion Of Fiber Sensing And Ultrasonic Guided Waves

Structural health monitoring(SHM)is an important means to improve the structural safety of aircraft and reduce maintenance costs.The theoretical research on the SHM technology is very rich after decades of development.However,the current research on the SHM technology is mostly the single sensing methods and it lacks the comprehensive research on multi-source sensing technology.Without the interaction of information between multiple sensors,it is difficult to satisfy the monitoring needs of complex structures and multiple physical fields.In this paper,a structural health monitoring method combining multi-source sensing and digital twinning is proposed based on the condition monitoring of a composite aircraft tail in the force-thermal coupling environment ground test.The method is used to monitor the structural state and make full use of the various information brought by multi-source sensing to establish a digital twin model to make a comprehensive analysis and prediction of structural state.In this paper,the simulated aircraft structure is subjected to bending moment loads in the complex environment,and the state and life prediction of metal and composite structures are carried out.The main contents of this paper are as follows:1)The monitoring method of multi-source sensing information fusion based on piezoelectric transducers(PZT)and optical fiber sensors is studied experimentally.And this paper proposes a step-by-step fusion Kalman filter fusion method to fuse multi-source sensing information.The experimental results show that the fusion damage diagnosis results are more stable and the accuracy of damage location is improved than the single signal’s diagnosis results.2)This paper explores the application of piezoelectric-fiber hybrid sensing damage monitoring method in damage propagation under the force-thermal coupling environment.A weighted adaptive Kalman filter fusion method is proposed to quantitatively analyze the damage size and the experimental results show that the method can improve the accuracy and stability of quantitative diagnosis of injury.At the same time,the digital twin model based on Paris theory,SHM and the finite element analysis is used to predict the life of the structure,and a simple experimental verification is carried out,which is helpful to further promote the development and application of digital twinning technology.3)This paper discusses the structural health monitoring method for the test of a composite aircraft under the complex force-thermal coupling environment and proposes a damage localization method perpendicular to the fiber direction which can solve the problem of optical fiber in the damage location of composite materials.Firstly,the SHM system is designed to monitor the state of the metal rudder shaft and composite structure of the tail according to the monitoring requirements,structural characteristics and load characteristics.Then,the composite panel was designed and manufactured to simulate the tail skin,and a test platform for simulating the tail wing bearing the aerodynamic moment load was built.The load,damage and damage expansion of the composite structure are monitored by multi-source sensing information fusion.This method can effectively monitor the damage and load state of the composite material without substantially increasing the weight of the tail wing and lays a solid foundation for the ground monitoring experiment of the tail wing.