scholarly journals Non-destructive investigation of polymer-metal bonds using a VibroMap1000 holographic vibrometer

2019 ◽  
Vol 299 ◽  
pp. 04010
Author(s):  
Zawadzki Pawel ◽  
Meijer Frans ◽  
Stachowska Ewa ◽  
Legutko Stanisław
Keyword(s):  
Processing System ◽  
Accurate Assessment ◽  
Non Destructive Testing ◽  
Data Processing System ◽  
Destructive Testing ◽  
Frequency Scanning ◽  
Polymer Metal ◽  
Set Up ◽  
Non Destructive ◽  
Metal Bonds

We developed a method to test polymer-metal bonds using a VibroMap1000 holographic vibrometer. The set-up and the data processing system allow non-destructive testing of polymer-metal bonds for samples of a specific size and structure. Frequency scanning from 200 Hz - 20 kHz provides characteristics of the sample. Because the method is non-destructive the sample can be studied afterwards with other methods too. These combined with the measurements of the holographic vibrometer, can create a complete and accurate assessment of the state of polymer-metal bonds. We present some preliminary results.

Non-Destructive Testing of Mass Produced Components by Natural Frequency Measurements

1985 ◽  
Vol 199 (3) ◽  
pp. 161-168 ◽  
Author(s):  
P Cawley
Keyword(s):  
Natural Frequencies ◽  
Production Quality ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Production Quality Control ◽  
Cross Sectional ◽  
Dimensional Changes ◽  
Single Section ◽  
Set Up ◽  
Non Destructive

Vibrations in engineering components may be excited by a light tap and the vibration response may be measured with a microphone and displayed as a frequency spectrum from which the natural frequencies of the component can be extracted. Changes in the natural frequencies of the various modes are observed when small defects such as cracks are present. The use of this technique for the production quality control of mass produced components has been investigated. Tests have been carried out on a cantilever beam, a piston-shaped component and a pulley wheel. It has been shown that, in the absence of dimensional variations, defects removing between 0.5 and 2 per cent of the cross-sectional area of the component at a single section may be detected, the precise size depending on the geometry of the component and the location of the defect. Dimensional variations reduce this sensitivity, but a method has been developed for correcting the results for dimensional changes, without the need for more measurements to be taken. The results show that, unless the likely location of a defect is known in advance, it is essential to measure the natural frequencies of more than one mode of vibration. The test takes less than ten seconds to set up, about one second to carry out and is amenable to automation.

scholarly journals Design and Development of Aircraft Propeller Maintenance Facility for General Aviation

Khazanah ◽  
2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Amman Mujahid ◽  
Keyword(s):  
Environmental Impact ◽  
Visual Inspection ◽  
General Aviation ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Proactive Approach ◽  
Maintenance Techniques ◽  
Set Up ◽  
Environment Sustainability ◽  
Non Destructive

Since the first flight and introduction of propellers from marine to the sky, various maintenance techniques have been employed to maintain aircraft propellers. With the advancement in the operation and safety of flight, propellers have been manufactured in various materials, shapes and measurements. The design developed is based on the concept of a “single stop shop facility”. The propeller maintenance facility majorly focuses the general aviation in order to provide them a set up that primarily focuses on the maintenance of propellers in order to avoid malfunctions resulting in accidents and failures. The maintenance procedures for workbench include static balancing, blade tracking, cleaning, visual inspection, corrosion removal and Non-Destructive Testing (NDT). The developed facility has an accelerated scalability with the provision of facilitating Non-Destructive Testing that is performed on the workbench. The non-destructive testing results in assuring reliability and safety of the propellers as per the modern maintenance practices. The workbench developed focuses over the environment sustainability as it functions on the concept of sustainable maintenance that involves reduced unnecessary maintenance. Moreover, the currently developed facility integrates a proactive approach involving reduced use of energy in order to produce less waste and environmental impact. At present, the workbench has been manufactured and is being tested for propeller maintenance procedures.

Estimation of Leaf Thickness with Remote Sensing

2012 ◽  
Vol 263-266 ◽  
pp. 339-345 ◽  
Author(s):  
Xue Yan Sui ◽  
Xiaodong Zhang ◽  
Yong Wang ◽  
Shao Kun Li
Keyword(s):  
Remote Sensing ◽  
Real Time ◽  
Regression Models ◽  
Leaf Thickness ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Important Index ◽  
Growing Conditions ◽  
Set Up ◽  
Non Destructive

Leaf thickness is one important index of describing plant growing conditions. But the measurements now are all tedious and destructive. In order to carry out real-time, live, non-destructive testing of leaf thickness, the study took cotton leaves as the research object. The correlations of leaf thickness with reflectance, vegetable index and spectral figure index were analyzed separately. And then the cause of correlation was studied. Three regression models were set up with the 3 parameters which had high correlation with leaf thickness. Among these models, the highest relative error is 7.4%, and the RMSE is 0.051 mm. It is feasible to measure alive leaf thickness untouchably with Hyper spectrum.

scholarly journals A Comparison among Different Ways to Investigate Composite Materials with Lock-In Thermography: The Multi-Frequency Approach

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2525
Author(s):  
Ester D’Accardi ◽  
Davide Palumbo ◽  
Umberto Galietti
Keyword(s):  
Low Cost ◽  
Fiber Reinforced Polymers ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Carbon Fiber Reinforced Polymers ◽  
Reinforced Polymers ◽  
Advantages And Disadvantages ◽  
Set Up ◽  
Lock In ◽  
Non Destructive

The main goal of non-destructive testing is the detection of defects early enough to avoid catastrophic failure with particular interest for the inspection of aerospace structures; under this aspect, all methods for fast and reliable inspection deserve special attention. In this sense, active thermography for non-destructive testing enables contactless, fast, remote, and not expensive control of materials and structures. Furthermore, different works have confirmed the potentials of lock-in thermography as a flexible technique for its peculiarity to be performed by means of a low-cost set-up. In this work, a new approach called the multi-frequency via software approach (MFS), based on the superimposition via software of two square waves with two different main excitation frequencies, has been used to inspect a sample in carbon fiber reinforced polymers (CFRP) material with imposed defects of different materials, sizes and depths, by means of lock-in thermography. The advantages and disadvantages of the multi-frequency approach have been highlighted by comparing quantitatively the MFS with the traditional excitation methods (sine and square waves).

Non destructive testing of works of art by terahertz analysis

2013 ◽  
Vol 64 (2) ◽  
pp. 21001 ◽  
Author(s):  
Jean-Luc Bodnar ◽  
Jean-Jacques Metayer ◽  
Kamel Mouhoubi ◽  
Vincent Detalle
Keyword(s):  
Non Destructive Testing ◽  
Destructive Testing ◽  
Works Of Art ◽  
Non Destructive

Modeling of a sensitive element on a planar mushroom-shaped metamaterial for non-destructive testing and searching for inhomogeneities in technological media

2020 ◽  
pp. 54-59
Author(s):  
A. A. Yelizarov ◽  
A. A. Skuridin ◽  
E. A. Zakirova
Keyword(s):  
Sensitive Element ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Resonant Frequency Shift ◽  
Maltese Cross ◽  
Informative Parameters ◽  
Non Destructive ◽  
Cross Type ◽  
Electrodynamic Structure ◽  
Electrophysical Parameters

A computer model and the results of a numerical experiment for a sensitive element on a planar mushroom-shaped metamaterial with cells of the “Maltese cross” type are presented. The proposed electrodynamic structure is shown to be applicable for nondestructive testing of geometric and electrophysical parameters of technological media, as well as searching for inhomogeneities in them. Resonant frequency shift and change of the attenuation coefficient value of the structure serve as informative parameters.

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