13th International Conference on Fracture June 16–21, 2013, Beijing, China -8- experimental behavior of the output voltage u(t) of the photodiode, which is obtained on high-speed storing oscillograph at the investigation of wave processes in a plate subjected shock loading. The comparison of the theoretical and experimental results allows us to make a conclusion that the represented above assumptions are valid. Figure 5. Experimental oscillogram of the output signal from the photodetector In the experimental arrangement laser LCM-S-111-50-NP25 with wavelength = 532 nm and coherence length more 50 m is used. For the measurement of the dynamic displacements with very high frequency p-i-n photodiode with frequency range 20 MHz. Thus, the new method of registration dynamic displacements of the investigation surface of object in large range of measured value of displacements and in the large frequency range on the basis of the analysis of distribution of intensity in the single speckle is considered. Advantage of the offered method is that its use doesn't demand a careful adjustment of elements of optical system and allows to overcome restrictions which are connected with existence of own noise (speckles) in the holographic and speckle interferometry and to register dynamic displacements in real time. References [1] B.J.Thompson, Electronic speckle pattern interferometry principles and practice, Bellingham, Washington: SPIE Optical Engineering Press; 1996. [2] Y. Arai, H. Hirai, S. Yokozeki, High-resolution dynamic measurement using electronic speckle pattern interferometry based on multi-camera technology, Optics and Lasers in Engineering, 46 (2008), 733– 738. [3] L.X. Yang, M. Schuth, D. Thomas, Y.H. Wang, Stroboscopic digital speckle pattern interferometry for vibration analysis of microsystem, Optics and Lasers in Engineering, 47 (2009), 252– 258. [4] Wang Wei-Chung, Jiong-ShiunHsu, Investigation of vibration characteristics of bonded structures by time-averaged electronic speckle pattern interferometry, Optics and Lasers in Engineering, 48 (2010) 958–965. [5] E.M. Barj, M. Afifi, A.A. Idrissi, K. Nassim, S. Rachafi, Speckle correlation fringes denoising using stationary wavelet transform. Application in the wavelet phase evaluation technique, Optics & Laser Technology, 38, № 7, (2006) 506-511. [6] R.A. Braga, W.S. Silva, T. Sáfadi, C.M.B. Nobre, Time history speckle pattern under statistical view, Optics Communications, 281 №9,1 (2008) 2443-2448. [7] S. Mirza, P. Singh, R. Kumar, A.L. Vyas, C. Shakher, Measurement of transverse vibrations/visualization of mode shapes in square plate by using digital speckle pattern interferometry and wavelet transform, Optics and Lasers in Engineering, 44 № 1 (2006) 41-55. [8] M. Born, E. Wolf, Principles of Optics, Pergamon Press, Oxford, London, New York, 1968.
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