A new damage feature based on wavelet packet transform for damage detection under ambient vibration

2010 ◽  
pp. 787-792
Author(s):  
G Wang ◽  
Z Liu ◽  
G Yan
Keyword(s):  
Damage Detection ◽  
Wavelet Packet ◽  
Wavelet Packet Transform ◽  
Ambient Vibration ◽  
Feature Based

scholarly journals Nonlinear Ultrasonic Detection Method for Delamination Damage of Lined Anti-Corrosion Pipes Using PZT Transducers

2018 ◽  
Vol 8 (11) ◽  
pp. 2240 ◽  
Author(s):  
Xiaobin Hong ◽  
Yuan Liu ◽  
Xiaohui Lin ◽  
Zongqiang Luo ◽  
Zhenwei He
Keyword(s):  
Damage Detection ◽  
Detection Method ◽  
Wavelet Packet ◽  
Nonlinear Coefficient ◽  
Wavelet Packet Transform ◽  
Third Order ◽  
Ultrasonic Detection ◽  
Hilbert Huang Transform ◽  
Nonlinear Ultrasonic ◽  
Delamination Damage

Lined anti-corrosion pipes are widely used in oil and gas, petrochemical, pharmaceutical industries. However, defects, especially delamination, may occur in the production and service of pipes which result in safety accidents. Based on nonlinear ultrasonic theory, this paper studied the delamination detection method using the nonlinear harmonics for lined anti-corrosion pipes. The response characteristics of the anti-corrosion pipe were obtained through a sweep sine response experiment and the preferred excitation frequency was determined. The Wavelet Packet transform and Hilbert–Huang transform is applied for signal process and feature extraction. Then, a series of experiments were carried out and the results were analyzed and discussed. The results showed that a second-order and third-order nonlinear coefficient increased with the delamination damage. The amplitude of second-harmonic is much stronger than the third-order one. The mean squared error of the nonlinear coefficient, which was processed by Wavelet Packet transform and Hilbert–Huang transform, is smaller than wavelet packet transform and Discrete Fourier transform or processed only Hilbert–Huang transform. The higher harmonics can describe the change of delamination damage, which means that the nonlinear ultrasonic detection method could use for damage detection of anti-corrosion pipe. The nonlinear higher-harmonic is sensitive to delamination damage. The nonlinear ultrasonic method has the potential for damage detection for lined anti-corrosion pipes.

Damage Detection in Offshore Free Span Pipelines Using Wavelet Packet Transform

2011 ◽  
Author(s):  
Sajad Shahverdi ◽  
Mohammad Ali Lotfollahi-Yaghin ◽  
Mohammad Hossein Aminfar ◽  
Ramin Valizadeh
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Wavelet Packet ◽  
Offshore Structures ◽  
Wavelet Packet Transform ◽  
Detection Methods ◽  
Mode Shapes ◽  
Mathematical Tool ◽  
Energy Rate ◽  
Modal Properties

During the service life, offshore structures continually accumulate damage as a result of applying the various environmental forces. Clearly the development of strong techniques for early damage detection is very important to avoid the possible occurrence of a disastrous structural failure. Most of vibration-based damage detection methods require the modal properties that are obtained from measured signals through the system identification techniques. However, the modal properties such as natural frequencies and mode shapes are not such a good sensitive indication of structural damage. The wavelet packet transform (WPT) is a mathematical tool that has a special advantage over the traditional Fourier transform in analyzing non-stationary signals. In this study, a damage detection index called wavelet packet energy rate index (WPERI), is used for the damage detection of offshore free span pipelines. The measured dynamic signals are decomposed into the wavelet packet components and the wavelet energy rate index is computed to indicate the structural damage. It is observed that this method can be used for damage detection of this kind of structures.

Mistuning identification in a bladed disk using wavelet packet transform

2017 ◽  
Vol 229 (3) ◽  
pp. 1275-1295 ◽  
Author(s):  
N. Jamia ◽  
P. Rajendran ◽  
S. El-Borgi ◽  
M. I. Friswell
Keyword(s):  
Wavelet Packet ◽  
Wavelet Packet Transform ◽  
Bladed Disk
Sign in / Sign up

Export Citation Format

Share Document