Home > Search Results: 999C1a:GA103/06/1711
Search:
Search Tips :: Advanced Search
Search collections:
Sort by: Display results: Output format:
National Repository of Grey Literature 4 records found  Search took 0.00 seconds. 
NONDESTRUCTIVE EVALUATION OF CONCRETE STRUCTURES BY NONLINEAR ULTRASONIC SPECTROSCOPY METHODS
 Převorovský, Zdeněk ; Krofta, Josef ; Chlada, Milan
Facilities of nonlinear ultrasonic spectroscopy for defects detection in steel-reinforced concrete structures are discussed in the paper. Results are shown from non-destructive evaluation of concrete block samples reinforced with intact and corroded armature. Seven piezoelectric transducers were glued on the sample surface. One of them was used to harmonic excitation of the structure with frequency f1=45 kHz and stepwise growing amplitude. Among other 6 transducers one was multiplexed as a second transmitter of harmonic signal with f2=217 kHz and remaining sensors were receiving structural response on 2-frequency excitation. Most pronounced spectral differences between samples with corroded and intact reinforcement were observed on amplitude dependence of 3f1/2f1 ratio and f2-3f1 sidebands, which can be considered as nonlinear parameters characterizing concrete damage.
Detailed record
Ultrazvukové časově-reversní zrcadlo-numerická simulace v desce s defektem
 Krofta, Josef ; Převorovský, Zdeněk
The time reversal mirror (TRM) is a method which can be effective in NDE of defects in materials. In this case an input ultrasonic wave is transmitted into the examined sample, then recorded by receiving transducers, time reversed and sent back by the same transducers. A simple numerical model of a solid plate was developed. Using this model, a simulation of TRM was performed. The propagation of ultrasonic waves used in time reversal method is studied. A number of tests with various configurations of transducers and defects and different methodology of the TRM procedure is simulated.
Detailed record
Time reversal acoustic used to defect detection in structures
 Převorovský, Zdeněk
Time reversal acoustics (TRA) method application in defects detection is described in the paper. Non-linear version of the TRA is discussed primarily.
Detailed record
Using of NEWS frequency mixing method for defects detection in aircraft structures
 Kvita, Pavel ; Převorovský, Zdeněk
Frequency mixing NEWS method application in defects detection in model aircraft structure is main goal of the paper.
Detailed record

Interested in being notified about new results for this query?
Subscribe to the RSS feed.
Digital Repository :: Search :: Submit :: Personalize :: Help
Powered by Invenio v1.1.2
Maintained by admin.invenio@techlib.cz
This site is also available in the following languages:
Česky  English