Disbond detection of composite repair patches on concrete structures using laser Doppler vibrometer

1996 ◽  
Author(s):  
Fanping P. Sun ◽  
Craig A. Rogers ◽  
Zaffir A. Chaudhry
Keyword(s):  
Concrete Structures ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Composite Repair ◽  
Disbond Detection

Nde of Tendon Ducts in Concrete Using 3D-Saft

1997 ◽  
Vol 503 ◽  
Author(s):  
M. Krause ◽  
H. Wiggenhauser ◽  
W. Müller ◽  
V. Schmitz
Keyword(s):  
Data Analysis ◽  
Ultrasonic Testing ◽  
Concrete Strength ◽  
Concrete Structures ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Impact Echo ◽  
Concrete Members ◽  
Testing Techniques ◽  
Post Tensioned

ABSTRACTPrestressed or post-tensioned concrete structures are vulnerable to hazardous corrosion, if the tendon ducts are not fully injected with grout. Also compaction faults reduce the concrete strength. Advanced ultrasonic testing techniques and data analysis have been utilized to evaluate ducts in concrete members nondestructively. A laser Doppler vibrometer is used as an ultrasonic receiver to automatically collect the data. With this method ducts could be investigated which are not accessible by other methods as radiography or impact-echo. Encouraging results on different specimens are presented.

Temperature coefficient of Young’s modulus of silver microwhiskers determined by a laser Doppler vibration measurement

2021 ◽  
pp. 2150350
Author(s):  
Yijun Jiang ◽  
Mingyuan Lu ◽  
Shiliang Wang ◽  
Han Huang
Keyword(s):  
Temperature Dependence ◽  
Temperature Coefficient ◽  
Single Crystals ◽  
Young’S Modulus ◽  
Vapor Deposition ◽  
Physical Vapor Deposition ◽  
Young's Modulus ◽  
Laser Doppler Vibrometer ◽  
Laser Doppler ◽  
Vibration Measurement

Temperature dependence of Young’s modulus of Ag microwhiskers was determined by a laser Doppler vibrometer. The Ag whiskers with diameters in sub-microns were synthesized by the use of physical vapor deposition (PVD). They have a five-fold twinned structure grown along the [1 1 0] direction. The temperature coefficient of Young’s modulus was measured to be [Formula: see text] ppm/K in the range of 300 K to 650 K. The measured values are very close to the reported values of [Formula: see text] ppm/K for bulk Ag single crystals. This finding can benefit the design of Ag-based micro/nano-electromechanical systems or micro/nano-interconnectors operated at elevated or lowered temperatures.

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