Ultrasonic modulated waves for diagnostics of concrete elements in bending

The paper presents the experimental study on the diagnostics of concrete elements with the use of nonlinear acoustic effects. The tests were conducted on a concrete plate subjected to ultrasonic waves modulated with and without an additional low frequency actuator. The experimental results showed that the new method based on the direct modulation of diagnostic ultrasonic waves also provided sub-harmonic frequencies that indicated the presence of damage. The new method does not require a low frequency actuator for generation of low frequency oscillations, and therefore, is more suitable for practical application.

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Diagnostics of concrete plate in bending with ultrasonic waves modulated by low frequency oscillations

Budownictwo i Architektura ◽

10.35784/bud-arch.2205 ◽

2013 ◽

Vol 12 (1) ◽

pp. 243-250

Author(s):

Błażej Meronk ◽

Krzysztof Wilde

Keyword(s):

Experimental Study ◽

Low Frequency ◽

Ultrasonic Waves ◽

Modulation Method ◽

Frequency Spectra ◽

Concrete Plate ◽

Low Frequency Oscillations ◽

Damaged Zone ◽

Nonlinear Acoustic ◽

Concrete Elements

The paper presents the experimental study on the inter-modulation method for the diagnostics of concrete elements. The tests were conducted on a concrete plate subjected to ultrasonic waves and low frequency vibrations. The nonlinear acoustic effects, recorded in the experiments, made it possible to detect the presence of damaged zones. Further studies are necessary to establish the relation between the sidebanes of frequency spectra and the size of the damaged zone.

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Analysis of Vibro-Acoustic Modulations in Nonlinear Acoustics Used for Impact Damage Detection - Numerical and Experimental Study

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.558.341 ◽

2013 ◽

Vol 558 ◽

pp. 341-348 ◽

Cited By ~ 5

Author(s):

Łukasz Pieczonka ◽

Andrzej Klepka ◽

Wieslaw Jerzy Staszewski ◽

Tadeusz Uhl ◽

Francesco Aymerich

Keyword(s):

Experimental Study ◽

Finite Element ◽

Composite Plate ◽

Natural Frequencies ◽

Impact Damage ◽

Low Frequency ◽

Fe Modeling ◽

Low Frequency Vibration ◽

Frequency Excitation ◽

Nonlinear Acoustic

The paper investigates experimentally the effect of low-frequency vibration on nonlinear vibro-acoustic wave modulations applied to the detection of Barely Visible Impact Damage (BVID) in a composite plate. Finite Element (FE) modeling was used in a pretest stage to identify different motion scenarios of delaminated surfaces and relate them to natural frequencies of the damaged plate. In particular the opening-closing and frictional sliding actions of the defected interfaces have been considered. Subsequently, the identified frequencies have been used for low frequency excitation in nonlinear acoustic experiments on a composite plate with impact damage.

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