1. Damage detection of composite plate based on an improved DAS algorithm by time difference due to anisotropy
- Author
-
Shuhao Cao, Qingwei Xia, Li Liu, Yanyan Liu, and Shiwei Ma
- Subjects
Materials science ,lcsh:Mechanical engineering and machinery ,Mechanical Engineering ,Mathematical analysis ,Fast Fourier transform ,Composite number ,02 engineering and technology ,01 natural sciences ,symbols.namesake ,020303 mechanical engineering & transports ,Fourier transform ,Lamb waves ,composite plate ,mixed mode ,two-dimensional fourier transform ,damage detection ,0203 mechanical engineering ,Composite plate ,0103 physical sciences ,symbols ,Group velocity ,lcsh:TJ1-1570 ,General Materials Science ,Phase velocity ,Anisotropy ,010301 acoustics - Abstract
This paper proposes a damage detection method based on an improved DAS imaging algorithm by introducing time difference due to anisotropy of composite material. First, the finite element characteristic frequency method is used to obtain the dispersion curve of the composite plate, and the validity of the dispersion curve is verified. Next, the average phase velocity of the Lamb wave at mixed modes in the composite plate is obtained by two-dimensional Fourier transform (2-D FFT). The mixed modal group velocity is calculated according to the corresponding phase velocity, the mean change rate of the phase velocity and the dispersion curve obtained by simulation. The time difference due to anisotropy of composite material is investigated, and the damage location is estimated by the delay-and-sum (DAS) imaging algorithm. Experiments on carbon fiber multilayer composite plates verify the effectiveness of the proposed method.
- Published
- 2020