Non-Destructive Testing of Wood Defects Based on Ultrasonic Technology

2013 ◽  
Vol 401-403 ◽  
pp. 1124-1128 ◽  
Author(s):  
Wen Shu Lin ◽  
Jin Zhuo Wu

The elm wood samples were tested by the technique of ultrasonic, and the testing results were analyzed by using the statistic software of SPSS. The results showed that the moister content of wood, wood crack, the sizes of holes and numbers of holes have significant influence on propagation parameters and dynamic modulus of elasticity. If there are holes or cracks in the propagation path, the propagation time will be longer, and the propagation velocity and wood modulus will decrease accordingly. The studying results of this paper will provide a sound background for the application of ultrasonic technique in detecting the inner defects of wood products and other wooden structures, and also offer important reference for testing the inner defects of old trees and ancient buildings.

2013 ◽  
Vol 401-403 ◽  
pp. 1119-1123 ◽  
Author(s):  
Wen Shu Lin ◽  
Jin Zhuo Wu

The elm wood samples were tested by the technique of stress wave, and the testing results were analyzed by using the statistic software of SPSS. The results showed that the moister content of wood, wood crack, the sizes of holes and numbers of holes have significant influence on propagation parameters and dynamic modulus of elasticity. Under the same specifications, the propagation time of the stress wave was longer in the wood with holes or cracks than the perfect wood samples, and the time become longer with the increasing the sizes and numbers of holes or cracks. The studying results of the thesis will provide a sound background for the application of stress-wave technique in detecting the inner defects of wood products and other wooden structures.


2014 ◽  
Author(s):  
Yuanfeng He ◽  
Wenwu Zhang

Development of industry demands better performance of equipments and devices than ever. The property of material used to produce the equipments is the precondition to ensure the quality. As equipments are usually required to be integral during the quality inspection, non-destructive testing (NDT) plays an increasingly import role in modern industry quality control. Different NDT methods are introduced and analyzed. The mechanism of ultrasonic exciting is described. After the ultrasonic is excited, the vibration signal can be detected by transducer or optical method which are then illustrated. In the section of development of laser ultrasonic technology, contributions made by various researchers in theoretic development, experiment, simulation and application are introduced and the corresponding content of the researches as well. The conclusion and the outlook of laser ultrasonic technique is made at the last.


Author(s):  
V. Hermawan ◽  
A. M. Al-Jumaily ◽  
M. Fatemi

Three non-destructive testing techniques are developed and investigated to determine the Young’s modulus of elasticity of the trachea and the results are compared with the standard uniaxial state of stress method. These techniques are based on: (1) simulating the trachea as a pressurized vessel and deducing a special relationship between the pressure and the radial strain; (2) using two hydrophones and determining the variation in acoustic transmittance caused by the presence of the trachea in a propagation path within a water-bath; (3) considering the trachea as a thin cylindrical shell and determining the resonance radial vibration response. Discussion is presented to identify the “pros” and “cons” of each technique and final practical recommendations are made.


ACTA IMEKO ◽  
2018 ◽  
Vol 7 (3) ◽  
pp. 111
Author(s):  
Lara De Giorgi ◽  
Giovanni Leucci ◽  
Davide Melica

Non-destructive testing by mean of ground penetrating radar were performed on the wooden elements constituting the roofing of the Cathedral of Foggia. These measurements were related to the restoration work of the roof.  Measurements campaign aimed at the assessment of the conservation status of the wooden elements of the all major and secondary elements of the truss of the nave, as well as on those main of the dome and the apse. Results show various abnormalities which correspond to nodes and/or slots. The presence of the nodes allow a rapid and accurate analysis of the electromagnetic waves velocity and the volumetric water content.


2013 ◽  
Vol 64 (2) ◽  
pp. 21001 ◽  
Author(s):  
Jean-Luc Bodnar ◽  
Jean-Jacques Metayer ◽  
Kamel Mouhoubi ◽  
Vincent Detalle

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