New laser interferometric schemes were recently developed in order to measure three components of the ultrasonic *** TEMPO 3D is a tri-component,two-wave mixing interferometer capable of simultaneously measuring the o...
详细信息
New laser interferometric schemes were recently developed in order to measure three components of the ultrasonic *** TEMPO 3D is a tri-component,two-wave mixing interferometer capable of simultaneously measuring the out-of-plane component as well as the two orthogonal in-plane components of the surface displacement,using a single laser *** wave types can be *** this paper,we describe this new technology,which constitutes an advance in ultrasonic field visualization.
Based on the phenomenon that the A scanning displacement is larger in the ultrasonic nondestructive *** blade work-piece coordinate system origin by precision scanning platform and find the corresponding relationship ...
详细信息
Based on the phenomenon that the A scanning displacement is larger in the ultrasonic nondestructive *** blade work-piece coordinate system origin by precision scanning platform and find the corresponding relationship between the blade work-piece coordinate system and the world coordinate system of *** to the principle of ultrasonic distance measurement,detect the distance in real time between probe and measured point in the process of scanning,and calculate the displacement deviation of the current position and track points by the ultrasonic echo time difference *** to the feedback information of the ultrasonic distance measurement,adjusting the scanning track of manipulator in real *** that the distance between the blade surface and the ultrasonic probe is constant and the ultrasonic wave is perpendicular to the surface of the *** experimental results show that after pose calibration the A scanning waveform is stable,the position of the C scanning defects can be acquired accurately,the detection result is good and the quality is reliable.
Multilayered carbon fibre reinforced polymer(CFRP)laminates are widely used in the aviation industry due to their excellent physical and mechanic properties,for example,high specific strength and high specific ***,res...
详细信息
Multilayered carbon fibre reinforced polymer(CFRP)laminates are widely used in the aviation industry due to their excellent physical and mechanic properties,for example,high specific strength and high specific ***,resin cracking and interface debonding may occur during the manufacturing process of aircrafts or during their service *** results may be caused by these defects if they cannot be detected and repaired in *** this study,the propagation of guided waves in a 10-layer CFRP laminate is ***,the interaction between guided waves and different defects in the laminate are simulated by the finite element method(FEM).Simulation results show that the first order guided wave is sensitive to the crack and debonding.
The defect echo signals are often polluted by power frequency of scan system and background noise when detecting internal and external flaw of thick wall pipe through ultrasonic testing *** for detecting tiny flaw of ...
详细信息
The defect echo signals are often polluted by power frequency of scan system and background noise when detecting internal and external flaw of thick wall pipe through ultrasonic testing *** for detecting tiny flaw of thick wall pipe,the lower amplitude echo signals are frequently submerged in *** packet threshold method can restrain the noise interference,however,the limitation and disadvantage of this method still *** response to this issue,an approach of denoising of wavelet packet and singular value decomposition(SVD)is advanced in this *** echo signals are decomposed with wavelet packet by utilizing the optimal wavelet *** high frequency noise is removed according to the energy distribution ratio of different frequency band and then the extracted energy distribution band is decom-posed by singular *** adaptive filter is realized eventually after determining the effective echo signal area through singular entropy *** show that the algorithm of denoising of wavelet packet and singular value decomposition can not only remove the high frequency noise,but also effectively remove the low frequency noise,echo signal-to-noise ratio(SNR)is improved greatly.
暂无评论