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MEMS Microphone Array Sensor for Air-Coupled Impact-Echo.

Groschup R, Grosse CU - Sensors (Basel) (2015)

Bottom Line: By using an array of MEMS (micro-electro-mechanical system) microphones, instead of a single receiver, several operational advantages compared to conventional sensing strategies in IE are achieved.The MEMS microphone array sensor is cost effective, less sensitive to undesired effects like acoustic noise and has an optimized sensitivity for signals that need to be extracted for IE data interpretation.The MEMS microphone array will make air-coupled IE measurements faster and more reliable.

View Article: PubMed Central - PubMed

Affiliation: Technische Universität München (TUM), Chair of Non-destructive Testing, Baumbachstr. 7, 81245 Munich, Germany. robin.groschup@tum.de.

ABSTRACT
Impact-Echo (IE) is a nondestructive testing technique for plate like concrete structures. We propose a new sensor concept for air-coupled IE measurements. By using an array of MEMS (micro-electro-mechanical system) microphones, instead of a single receiver, several operational advantages compared to conventional sensing strategies in IE are achieved. The MEMS microphone array sensor is cost effective, less sensitive to undesired effects like acoustic noise and has an optimized sensitivity for signals that need to be extracted for IE data interpretation. The proposed sensing strategy is justified with findings from numerical simulations, showing that the IE resonance in plate like structures causes coherent surface displacements on the specimen under test in an area around the impact location. Therefore, by placing several MEMS microphones on a sensor array board, the IE resonance is easier to be identified in the recorded spectra than with single point microphones or contact type transducers. A comparative measurement between the array sensor, a conventional accelerometer and a measurement microphone clearly shows the suitability of MEMS type microphones and the advantages of using these microphones in an array arrangement for IE. The MEMS microphone array will make air-coupled IE measurements faster and more reliable.

No MeSH data available.


Snapshot of a simulation of stress waves inside concrete and radiated acoustic waves [18].
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sensors-15-14932-f001: Snapshot of a simulation of stress waves inside concrete and radiated acoustic waves [18].

Mentions: The stress waves inside a concrete plate after an impact and the radiated waves in the surrounding air can be visualized by a 2D finite element simulation (Figure 1, [18]).


MEMS Microphone Array Sensor for Air-Coupled Impact-Echo.

Groschup R, Grosse CU - Sensors (Basel) (2015)

Snapshot of a simulation of stress waves inside concrete and radiated acoustic waves [18].
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541815&req=5

sensors-15-14932-f001: Snapshot of a simulation of stress waves inside concrete and radiated acoustic waves [18].
Mentions: The stress waves inside a concrete plate after an impact and the radiated waves in the surrounding air can be visualized by a 2D finite element simulation (Figure 1, [18]).

Bottom Line: By using an array of MEMS (micro-electro-mechanical system) microphones, instead of a single receiver, several operational advantages compared to conventional sensing strategies in IE are achieved.The MEMS microphone array sensor is cost effective, less sensitive to undesired effects like acoustic noise and has an optimized sensitivity for signals that need to be extracted for IE data interpretation.The MEMS microphone array will make air-coupled IE measurements faster and more reliable.

View Article: PubMed Central - PubMed

Affiliation: Technische Universität München (TUM), Chair of Non-destructive Testing, Baumbachstr. 7, 81245 Munich, Germany. robin.groschup@tum.de.

ABSTRACT
Impact-Echo (IE) is a nondestructive testing technique for plate like concrete structures. We propose a new sensor concept for air-coupled IE measurements. By using an array of MEMS (micro-electro-mechanical system) microphones, instead of a single receiver, several operational advantages compared to conventional sensing strategies in IE are achieved. The MEMS microphone array sensor is cost effective, less sensitive to undesired effects like acoustic noise and has an optimized sensitivity for signals that need to be extracted for IE data interpretation. The proposed sensing strategy is justified with findings from numerical simulations, showing that the IE resonance in plate like structures causes coherent surface displacements on the specimen under test in an area around the impact location. Therefore, by placing several MEMS microphones on a sensor array board, the IE resonance is easier to be identified in the recorded spectra than with single point microphones or contact type transducers. A comparative measurement between the array sensor, a conventional accelerometer and a measurement microphone clearly shows the suitability of MEMS type microphones and the advantages of using these microphones in an array arrangement for IE. The MEMS microphone array will make air-coupled IE measurements faster and more reliable.

No MeSH data available.