Impact source identification in finite isotropic plates using a time-reversal method: experimental study

SummaryA theoretical and experimental study is made of the stresses and strains around circular holes in plates reinforced with carbon fibre filament-wound discs. An analytical solution is given for infinite isotropic plates subjected to uniform tension, but for orthotropic carbon fibre plates the finite-element displacement method of analysis is used. The filament-wound discs are found to be efficient in reducing the stresses around the holes with the principal stresses being taken, in the main, by the strong fibres. There is reasonable agreement with the experimental results for the uniform tension cases, but results from tests on bolt-loaded holes do not correlate as well with theory.

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Time Reversal Based Timing Acquisition for Ultra-Wideband Wireless Communications: Numerical and Experimental Study

Wireless Personal Communications ◽

10.1007/s11277-014-1691-5 ◽

2014 ◽

Vol 77 (4) ◽

pp. 3013-3026 ◽

Cited By ~ 1

Author(s):

Deshuang Zhao ◽

Bing-Zhong Wang ◽

Yuanwei Jin

Keyword(s):

Experimental Study ◽

Wireless Communications ◽

Time Reversal ◽

Ultra Wideband ◽

Timing Acquisition

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Development of Time-Reversal Method for Impact Source Identification on Plate Structures

Shock and Vibration ◽

10.1155/2013/312169 ◽

2013 ◽

Vol 20 (3) ◽

pp. 561-573 ◽

Cited By ~ 9

Author(s):

Chunlin Chen ◽

Yulong Li ◽

Fuh-Gwo Yuan

Keyword(s):

Impact Loading ◽

Time Reversal ◽

Source Identification ◽

Transfer Functions ◽

Plate Thickness ◽

Time History ◽

Numerical Verification ◽

Impact Location ◽

Location Detection ◽

The Impact

This paper presents a detailed study on the impact source identification of a plate structure using time-reversal (T-R) method. Prior to impact monitoring, the plate is calibrated (or characterized) by transfer functions at discrete locations on the plate surface. Both impact location and impact loading time-history are identified using T-R technique and associated signal processing algorithms. Numerical verification for finite-size isotropic plates under low velocity impacts is performed to demonstrate the versatility of T-R method for impact source identification. The tradeoff between accuracy of the impact location detection and calibration spacing is studied in detail. In particular, the effect of plate thickness on calibration spacing has been examined. A number of parameters selected for determining the impact location, approximated transfer functions and steps taken for reconstructing the impact loading time-history are also examined. Two types of noise with various intensities contaminated in strain response and/or transfer functions are investigated for demonstrating the stability and reliability of the T-R method. The results show that T-R method is robust against noise in impact location detection and force reconstruction in circumventing the inherent ill-conditioned inverse problem. Only transfer functions are needed to be calibrated and four sensors are requested in T-R method for impact identification.

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