scholarly journals 2D size, position and shape definition of defects by B-scan image analysis

2015 ◽  
Author(s):  
Michele Scafidi ◽  
Donatella Cerniglia ◽  
Tommaso Ingrassia
Keyword(s):  
Image Analysis ◽  
Cross Section ◽  
Automatic Inspection ◽  
Structural Components ◽  
Laser Ultrasonic ◽  
Non Destructive Evaluation ◽  
Ultrasonic Techniques ◽  
Definition Of ◽  
B Scan Images ◽  
Non Destructive

The non-destructive evaluation of defects by automatic procedures is of great importance for structural components. Thanks to the developments of the non-contact ultrasonic techniques, the automation of the inspections is gaining a progressively important role. In this work, an automatic inspection technique for the evaluation of defects by the analysis of B-scan images obtained by a laser ultrasonic system is presented. The data are extracted directly from a B-scan map obtained for a panel with internal defects, and are used to build an image of the cross section of the panel. The proposed automatic procedure allows the definition of size, position and shape of defects in panels of known thickness.

scholarly journals Monitoring of Thermal Aging of Aluminum Alloy via Nonlinear Propagation of Acoustic Pulses Generated and Detected by Lasers

2019 ◽  
Vol 9 (6) ◽  
pp. 1191 ◽  
Author(s):  
Mengmeng Li ◽  
Alexey Lomonosov ◽  
Zhonghua Shen ◽  
Hogeon Seo ◽  
Kyung-Young Jhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloy ◽  
Aluminum Alloys ◽  
Yield Strength ◽  
Thermal Aging ◽  
Finite Amplitude ◽  
Quadratic Nonlinearity ◽  
Laser Ultrasonic ◽  
Ultrasonic Techniques ◽  
Non Destructive

Nonlinear acoustic techniques are established tools for the characterization of micro-inhomogeneous materials with higher sensitivity, compared to linear ultrasonic techniques. In particular, the evaluation of material elastic quadratic nonlinearity via the detection of the second harmonic generation by acoustic waves is known to provide an assessment of the state variation of heat treated micro-structured materials. We report on the first application for non-destructive diagnostics of material thermal aging of finite-amplitude longitudinal acoustic pulses generated and detected by lasers. Finite-amplitude longitudinal pulses were launched in aluminum alloy samples by deposited liquid-suspended carbon particles layer irradiated by a nanosecond laser source. An out-of-plane displacement at the epicenter of the opposite sample surface was measured by an interferometer. This laser ultrasonic technique provided an opportunity to study the propagation in aluminum alloys of finite-amplitude acoustic pulses with a strain up to 5 × 10−3. The experiments revealed a signature of the hysteretic quadratic nonlinearity of micro-structured material manifested in an increase of the duration of detected acoustic pulses with an increase of their amplitude. The parameter of the hysteretic quadratic nonlinearity of the aluminum alloy (Al6061) was found to be of the order of 100 and to exhibit more than 50% variations in the process of the alloy thermal aging. By comparing the measured parameter of the hysteretic quadratic nonlinearity in aluminum alloys that were subjected to heat-treatment at 220 °C for different times (0 min, 20 min, 40 min, 1 h, 2 h, 10 h, 100 h, and 1000 h), with measurements of yield strength in same samples, it was established that the extrema in the dependence of the hysteretic nonlinearity and of the yield strength of this alloy on heat treatment time are correlated. This experimental observation provides the background for future research with the application goal of suggested nonlinear laser ultrasonic techniques for non-destructive evaluation of alloys’ strength and rigidity in the process of their heat treatment.

scholarly journals Growth of pineapple plantlets during acclimatisation can be monitored through automated image analysis of the canopy

2020 ◽  
Vol 4 (4) ◽  
pp. 223-229
Author(s):  
Guillermo Soto ◽  
Gustavo Lorente ◽  
Jessica Mendoza ◽  
Evelio Dany Báez ◽  
Carlos Manuel Lorenzo ◽  
...  
Keyword(s):  
Image Analysis ◽  
Automated Image Analysis ◽  
Plant Phenotyping ◽  
Tropical Fruit ◽  
Planting Material ◽  
Non Destructive Evaluation ◽  
Plantlet Growth ◽  
Canopy Area ◽  
Mathematical Relationships ◽  
Non Destructive

AbstractPineapple is an economically important tropical fruit crop, but the lack of adequate planting material limits its productivity. A range of micropropagation protocols has been developed over the years to address this shortfall. Still, the final stage of micropropagation, i.e. acclimatisation, remains a challenge as pineapple plantlets grow very slowly. Several studies have been conducted focusing on this phase and attempting to improve plantlet growth and establishment, which requires tools for the non-destructive evaluation of growth during acclimatisation. This report describes the use of semi-automated and automated image analysis to quantify canopy growth of pineapple plantlets, during five months of acclimatisation. The canopy area progressively increased during acclimatisation, particularly after 90 days. Regression analyses were performed to determine the relationships between the automated image analysis and morphological indicators of growth. The mathematical relationships between estimations of the canopy area and the fresh and dry weights of intact plantlets, middle-aged leaves (D leaves) and roots showed determination coefficients (R2) between 0.84 and 0.92. We propose an appropriate tool for the simple, objective and non-destructive evaluation of pineapple plantlets growth, which can be generally applied for plant phenotyping, to reduce costs and develop streamlined pipelines for the assessment of plant growth.

scholarly journals Laser ultrasonic surface wave dispersion technique for non-destructive evaluation of human dental enamel

2009 ◽  
Vol 17 (18) ◽  
pp. 15592 ◽  
Author(s):  
Hsiao-Chuan Wang ◽  
Simon Fleming ◽  
Yung-Chun Lee ◽  
Sue Law ◽  
Michael Swain ◽  
...  
Keyword(s):  
Surface Wave ◽  
Dental Enamel ◽  
Wave Dispersion ◽  
Surface Wave Dispersion ◽  
Laser Ultrasonic ◽  
Non Destructive Evaluation ◽  
Dispersion Technique ◽  
Non Destructive
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