Research on composites damage identification based on power spectral density and lamb wave tomography technology in strong noise environment.

Lamb wave is widely studied in the non-destructive testing of composite materials due to its wide detection range and high sensitivity to defects. In order to solve the problem of extracting the effective signal of damage in a strong noise environment to improve the accuracy of damage location determination. A damage location imaging method based on power spectral density and Lamb wave tomography is proposed in this paper. The damage location imaging of composite materials under strong noise environment is realized through simulation and experiment respectively. Firstly, the simulation analysis the propagation characteristics of Lamb waves in composite materials. The circular sensor array is evenly arranged on the composite material. Each sensor is used as an actuator to generate Lamb wave in turn clockwise. Other sensors are responsible for collecting signals. Strong noise is added to the collected signal to simulate the signal collected in the strong noise environment. Finally, the damage information is characterized by power spectral density to determine the damage factor, and by using the probability imaging algorithm, the damage location imaging is totally realized. The experimental results show that the maximum error of imaging positioning for single damage and multiple damage under strong noise environment is 5.10 mm and 8.04 mm, respectively. This method does not need to pretreatment the signal with strong noise, and can directly image the original signal. At the same time, the extraction process of complex reflected signals is avoided, and it has a great potential in the location and identification of composite materials damage in a strong noise environment. [ABSTRACT FROM AUTHOR]