A Time Reversed Guided Wave Method for Bolt Loosening Detection of Aerospace Thermal Protection System Panels

2018 ◽  
Author(s):  
Guannan Wu ◽  
Chao Xu ◽  
Fei Du ◽  
Weidong Zhu
Keyword(s):  
Thermal Protection ◽  
Guided Wave ◽  
Thermal Protection System ◽  
Protection System ◽  
Wave Method ◽  
Bolt Loosening

scholarly journals A Modified Time Reversal Method for Guided Wave Detection of Bolt Loosening in Simulated Thermal Protection System Panels

Complexity ◽  
2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Guan-nan Wu ◽  
Chao Xu ◽  
Fei Du ◽  
Wei-dong Zhu
Keyword(s):  
Time Reversal ◽  
Thermal Protection ◽  
Tone Burst ◽  
Guided Wave ◽  
Thermal Protection System ◽  
Protection System ◽  
Damage State ◽  
Wave Detection ◽  
Reconstructed Signal ◽  
Bolt Loosening

In this work, a modified time reversal method is proposed for guided wave detection and localizing loosened bolt in a complicated multibolt-jointed structure. Different from the traditional time reversal guided wave method, the response signal due to a tone burst input received at the healthy state is time reversed and recorded as a standard reemitting signal. In the detection process, this recorded standard signal is used for all damage cases to yield time reversal-focalized reconstruction signals. This largely improves the sensitivity of the focalized signal to damage state. In this paper, the peak amplitude of the focalized wave packet in the reconstructed signal is calculated and utilized as tightness index. By bonding PZT transducers at different joint locations inside the structure, multiple tightness indices, where each tightness index presents the correlation between the current joint condition to its healthy condition at the joint, can be obtained. To analyze a large number of tightness indices, a principle component analysis method is introduced, and a neural network-based loosening detection method is proposed. The proposed method is experimentally validated in a simulated double-layer bolt-jointed thermal protection system panel. Experimental results illustrate that the proposed method is effective to identify and localized the bolt loosening in complicated multibolt-jointed structure. The detection and identification of the location of multibolt loosening is realized.

Study of Ablative Thermal Protection System with Density Gradient

2021 ◽  
Vol 19 (1) ◽  
pp. 116-122
Author(s):  
Toshiyuki SUZUKI ◽  
Yuki KUBOTA ◽  
Yuichi ISHIDA ◽  
Takuya AOKI ◽  
Kazuhisa FUJITA ◽  
...  
Keyword(s):  
Density Gradient ◽  
Thermal Protection ◽  
Thermal Protection System ◽  
Protection System

scholarly journals Advanced metallic thermal protection system development

2002 ◽  
Author(s):  
M. Blosser ◽  
R. Chen ◽  
I. Schmidt ◽  
J. Dorsey ◽  
C. Poteet ◽  
...  
Keyword(s):  
Thermal Protection ◽  
System Development ◽  
Thermal Protection System ◽  
Protection System

Multilayer SiC for thermal protection system of space vehicles with decreased thermal conductivity through the thickness

2010 ◽  
Vol 30 (8) ◽  
pp. 1833-1840 ◽  
Author(s):  
S. Biamino ◽  
A. Antonini ◽  
C. Eisenmenger-Sittner ◽  
L. Fuso ◽  
M. Pavese ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Protection ◽  
Thermal Protection System ◽  
Protection System ◽  
Space Vehicles
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