Research Of Ultrasonic Wave Propagation In The Composites

With Chinese aerospace technology developing rapidly, various composite materials are applied more widely. Carbon fiber reinforced composite materials have excellent performances, and thus the proportion of the composite material applied in the civil aircraft is larger. Due to the unique manufacturing process of the composite material, it is easy to get the defects such as delamination and pores in the molding process. When the defects accumulate to a certain extent, the performance of the component will decline sharply. Currently ultrasonic testing has become one of the most important and mature non-destructive testing methods of the composite materials. Researching ultrasonic propagation characteristics of carbon fiber-reinforced composite materials and ensuring the reliability of the ultrasonic testing has vital engineering significance.The details of the paper were to study and analyze ultrasonic wave propagation in the carbon fiber reinforced composites. The single-layer composite board was selected as the object. The focus was to use the finite element method, establish a finite element model of ultrasonic testing, and simulate ultrasonic wave propagating in carbon fiber reinforced composites.Firstly, ultrasonic propagation in the isotropic solid was studied. Finite element method was used to study the ultrasonic wave propagation in the isotropic solid. The ultrasonic sound field which had defects was compared with defect-free ultrasonic sound field, to analyze the differences and variations between them. Ultrasonic wave propagation in the solid could be visualized through the wave field snapshots. Then, the controlling law for electronic scanning was combined with wave equation in the isotropic solid to establish finite element model, simulating the radiation field of linear phased array transducer. Furthermore, the ultrasonic wave propagation in the composites was studied. Then through modeling and simulation in the ANSYS software, the influences which the elastic coefficients and fiber direction have on the wave propagation are analyzed.Finally, the experimental data obtained by ultrasonic photoelastic method and the simulation results are compared. The results show that simulating ultrasonic wave propagation in carbon fiber reinforced composites by the finite element method is quite reliable and effective.