Research On Acoustic Emission Signal Propagation Characteristic Of FRP Composite Material Construction In The Process Of Damage

Composite material is widely used in engineering practice due to the advantages of lightweight, high strength and corrosion resistance of composite materials. But composite material products usually are anisotropic, at the same time, various process parameters will unable to be controlled precisely and used correctly, so the quality of the composite material structure is instable and the existence of defects is inevitable in the process of manufacture and use. So it is of great significance in the practical production to control defect inspection accuracyAcoustic emission testing technology has made great progress in the metal nondestructive testing of pressure vessels in these years. For the development of composite materials, acoustic emission technology is not only the nondestructive testing method of internal defects and damage, and has become the essential method of material performance study, strength test and evaluate service life. In the past twenty years, our lab researched on the acoustic emission characteristics of composite materials in metal material, sound mechanism and solid rocket motor shells, and has achieved fruitful research results.At first, this paper studied the propagation of transient stress wave in the structure of composite materials, using approximation theory of higher-order plate to establish the dispersion relation of the propagation of stress wave in the structure of FRP composite material laminates with the changes of the propagation angle. The work of stiffness calculation and drawing lamb dispersion curve had done in FRP composite material laminates of [0°]8,[90°]8,[+45°/-45°]2s.Then this paper simulated the propagation of the acoustic emission signal in the FRP composite material structure of [0°/90°]8, and got the propagation simulation model of acoustic emission in the FRP composite material structure. Understanding the signal propagation law of laminated plates, and provided theoretical basis for acoustic emission detection process. Finally, through to analyze the attenuation of wave and the amplitude of damage model in the tensile state of FRP composite material and the attenuation of amplitude in the interrupt lead state of FRP composite material container, got the attenuation rule of the signal propagation of FRP composite material, verified the validity of the numerical simulation of wave propagation and attenuation.