Evaluation of the Bolted Joints Fault of Aircraft Structure with Flexible Analytic Wavelet Transform

Bolted joints as a universal connecting are widely used in engineering especially in aircraft structure. While, being one of the most common failure components in aircraft structure, bolted joints failure forms are kind of difference and the most common failure form is bolt looseness, which is difficult to be observed directly, and it usually leads to destructive accidents. In this paper, the state of bolted joints is evaluated with the active method, which used lead zirconate titanate (PZT) sensors to create surface waves and to monitor their responses. Then using a flexible analytic wavelet transform (FAWT), FFT and DWT, the experimental data was analyzed and compared to detect the faults. All the results showed that FAWT is more suitable for the experiment of bolted joints.