Debonding defects detection of FMLs based on long pulsed infrared thermography technique

Gao

et al. 2022

Preprint

Self Cite

Honeycomb structures are widely used in aerospace and other fields, which are prone to debonding defects during service. Therefore, it is necessary to detect the defects of honeycomb structures in time. In this paper, the square-wave thermography detection principle was studied. The thermal conduction of CFRP / Al honeycomb panel with debonding defects was simulated by the finite element analysis. Pulse phase thermography (PPT), principal component analysis (PCA), thermal signal reconstruction (TSR), and total harmonic distortion (THD) ware studied for the original infrared image sequence. The signal-to-noise ratio (SNR) was calculated and the processing results ware compared. PCA-PC1 had the maximum SNR, which could reduce the background noise interference in square-wave thermography. Square-wave thermography can accurately detect and identify the debonding defects of the honeycomb structure.

Section: Simulation Results and Analysismentioning

confidence: 99%

Study on debonding defects detection of CFRP / Al honeycomb structure by Square-wave thermography

Gao

et al. 2022

Preprint

Self Cite

“…In the process of infrared image imaging, the captured infrared image sequence is usually with high noise and low contrast due to the interference of uneven heating and infrared radiation of surrounding environment. So, in order to improve the signal-to-noise ratio (SNR), background reduction and total harmonic distortion [12] algorithms were applied to process the image sequences, and normalization treatment was expressed by [13]:…”

Section: Experimental Studymentioning

confidence: 99%

Infrared thermal imaging detection of debonding defects in carbon fiber reinforced polymer based on pulsed thermal wave excitation

Zhao

et al. 2020

Therm sci

The carbon fiber reinforced composite has been widely used in many fields of the aviation industry due to the good resistance to fatigue damage, impact resistance, and easy processing. Firstly, the pulse heat conduction model of the carbon fiber reinforced composite is established, and the simulation experiment is completed based on the customized specimen with the defects. The influences of the thermal excitation power and pulse width on the defect detection effect are analyzed and obtained. The total harmonic distortion algorithm is used to process the experimental image sequence. The simulation and experimental results are compared and analyzed to verify their unity. It may provide the theoretical basis and empirical guidance for the defect detection of the composite materials.

J. of Syst. Eng. Electron.

“…The infrared seeker recognizes the target by sensing infrared energy. Therefore, the infrared seeker is easily disturbed by the infrared decoy that is released by the target [12,13]. The process from releasing the infrared decoy to seeker recognition of the real target is called the anti-infrared decoy state.…”

Section: Introductionmentioning

confidence: 99%

Line-of-sight rates extraction of roll-pitch seeker under anti-infrared decoy state

Li²,

Xia

2021

In this paper, the method of extracting guidance information such as the line-of-sight (LOS) rates under the anti-infrared decoy state for the roll-pitch seeker is researched. Coordinate systems which are used to describe the angles transform are defined. The LOS angles reconstruction model of the roll-pitch seeker in inertial space is established. A Kalman filter model for extracting LOS rates of the roll-pitch seeker is proposed. In this model, the target performs constant acceleration (CA) model maneuvers. The error model of LOS rates extraction under infrared decoy state is established. Several existing methods of extracting LOS rates under anti-infrared decoy state are listed in this paper. Different from the existing methods, a novel method that uses extrapolated values of target accelerations as filter measurements is proposed to solve the guidance information extraction problem under the anti-infrared decoy state. Numerical simulations are conducted to verify the effectiveness of the proposed method under different target maneuvering models such as the CA model, the CA extended model and the singer model. The simulation results show that the proposed method of extracting guidance information such as LOS rates for the rollpitch seeker under the anti-infrared decoy state is effective.