scholarly journals An Investigation of Corrosion Progression Using Laser Profilometry

2020 ◽  
Author(s):  
Hong Zhang ◽  
Ruikun Wu
Keyword(s):  
Mild Steel ◽  
Early Stage ◽  
Low Cost ◽  
Experimental Studies ◽  
Thickness Variation ◽  
Non Destructive Evaluation ◽  
Laser Profilometry ◽  
Corrosion Science ◽  
The Relationship ◽  
Non Destructive

Atmospheric corrosion progression characterisation on metal substrates is a major problem in the field of corrosion science and Non-destructive Evaluation (NDE). A laser profilometry has been used to characterise the corrosion on the mild steel plate at a low cost and high resolution. Four mild steel samples have been measured which exposed to the marine environment from 1 month to 10 months. Two features have been developed to characterise thickness variation in the corrosion layer. These features have been used to characterise corrosion progression through experimental studies. The relationship between these features and corrosion progression has been derived which is useful for corrosion progression measurement, early-stage corrosion prediction, and monitoring areas.

scholarly journals Non-Destructive Evaluation of Steel Surfaces after Severe Plastic Deformation via the Barkhausen Noise Technique

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1029 ◽  
Author(s):  
Miroslav Neslušan ◽  
Libor Trško ◽  
Peter Minárik ◽  
Jiří Čapek ◽  
Jozef Bronček ◽  
...  
Keyword(s):  
Shot Peening ◽  
Progressive Increase ◽  
Noise Signal ◽  
Barkhausen Noise ◽  
Noise Emission ◽  
Non Destructive Evaluation ◽  
Almen Intensity ◽  
The Relationship ◽  
Non Destructive ◽  
Severe Shot Peening

This paper reports about the non-destructive evaluation of surfaces after severe shot peening via the Barkhausen noise technique. Residuals stresses and the corresponding Almen intensity, as well as microstructure alterations, are correlated with the Barkhausen noise signal and its extracted features. It was found that residual stresses as well as the Barkhausen noise exhibit a valuable anisotropy. For this reason, the relationship between the Barkhausen noise and stress state is more complicated. On the other hand, the near-the-surface layer exhibits a remarkable deformation induced softening, expressed in terms of the microhardness and the corresponding crystalline size. Such an effect explains the progressive increase of the Barkhausen noise emission along with the shot-peening time. Therefore, the Barkhausen noise can be considered as a promising technique capable of distinguishing between the variable regimes of severe shoot peening.

scholarly journals A simple non-destructive method for estimating aboveground biomass of emergent aquatic macrophytes

2017 ◽  
Vol 29 (0) ◽  
Author(s):  
Laís Samira Correia Nunes ◽  
◽  
Antonio Fernando Monteiro Camargo ◽  
Keyword(s):  
Aboveground Biomass ◽  
Aquatic Macrophytes ◽  
Experimental Studies ◽  
River Estuary ◽  
Dry Mass ◽  
Biomass Estimation ◽  
Morphological Variables ◽  
The Individual ◽  
The Relationship ◽  
Non Destructive

Abstract: Aim Non-destructive methods for estimating aquatic macrophytes biomass may be employed by using indirect measurements, especially in experimental studies, thus enabling the conservation of plant samples. It is possible to estimate macrophyte biomass by developing mathematical equations that relate the plants’ dry mass to their morphological variables. The aim of this study was to evaluate the relationship between different morphological variables and biomass in order to determine which variable is easier to be obtained for the emergent aquatic macrophytes Crinum americanum and Spartina alterniflora. Methods We obtained the aboveground area and height of individuals of both species, with different sizes and distinct developmental stages. The samples were collected in the Itanhaém River Estuary (SP, Brazil). The plants were dried in a laboratory oven and weighed so as to obtain their dry mass. Simple linear regression analyses were applied to the morphological variables and the individual dry mass to obtain equations. Results For the both species, the relationship between area and biomass, and the relationship between individual height and biomass presented significant coefficients of determination (p < 0.0001). For the elaboration of models involving the individual height, we used only one morphological measure for each individual, whereas for models involving the individual area it was necessary to obtain more than one hundred morphological measurements per individual. Conclusions The morphological variables chosen are good attributes for estimating the aboveground biomass of C. americanum and S. alterniflora. Considering the models’ adjustment and the consumed time to obtain the measurements, we conclude that the individual height measurement is better for biomass estimation for both species.

Interrelationships of specific gravity, stiffness, and strength of yellow pine across five decades

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3815-3826
Author(s):  
Frederico Jose Nistal França ◽  
Rubin Shmulsky ◽  
Tedrick Ratcliff ◽  
Benjamin Farber ◽  
C. Adam Senalik ◽  
...  
Keyword(s):  
Specific Gravity ◽  
Modulus Of Rupture ◽  
Resource Monitoring ◽  
Non Destructive Evaluation ◽  
Three Samples ◽  
Yellow Pine ◽  
The Relationship ◽  
Non Destructive ◽  
Insight Into ◽  
Over Time

The interrelationships among specific gravity (SG), modulus of elasticity (MOE), and strength (modulus of rupture, MOR) are largely the foundational basis for non-destructive evaluation and testing. Resource monitoring and commercial structural lumber production often rely upon such non-destructive evaluation to predict the bending and/or tension strength of individual members. These technologies require routine calibration. In addition, it is important to know the extent to which a given resource may change over time. To that end, this study investigated the relationship among SG, MOE, and MOR of small clear specimens from three samples taken across an approximate 50-year period; 1965 to 2018. Coefficients of determination among these variables are presented along with the prediction equations. These findings can be used to gain insight into the reliability and stability of these relationships over time.

scholarly journals Assessment of the application of a SMART THUMPER™ as a low-cost and portable device used for stiffness estimation of timber products

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5838-5861
Author(s):  
Chandan Kumar ◽  
Adam Redman ◽  
William Leggate ◽  
Robert L. McGavin ◽  
Tony Dakin
Keyword(s):  
Low Cost ◽  
Cost Effective ◽  
Smartphone Application ◽  
Sample Length ◽  
Destructive Testing ◽  
Static Testing ◽  
Non Destructive Evaluation ◽  
Testing Technology ◽  
Timber Products ◽  
Non Destructive

Non-destructive evaluation methods for timber stiffness are gaining increased interest as an alternative to static testing since they can be fast, cost-effective, and transportable, as well as non-destructive. The objective of this study was to evaluate the accuracy and limitations of a newly developed smartphone application (SMART THUMPER™) for the non-destructive evaluation of timber stiffness properties. The study determined the effect of the length, density (species), and cross-section sizes of the timber samples on the stiffness results. The results were compared to beam identification by non-destructive grading (BING©), an existing commercial non-destructive testing technology for evaluating the mechanical quality of wood and other materials. It was found that the application can be used to reliably estimate the stiffness of various timber products with a resonance frequency value below 2000 Hz. Frequencies greater than 2000 Hz were found to induce errors due to the smartphone microphone, which is engineered to acquire a lower frequency range. A reliability matrix providing an indication of the accuracy of SMART THUMPER™ estimation was presented, which may also prove useful in selecting appropriate sample lengths prior to testing. The sample length or dimensions can be manipulated to lower the frequency, and hence, to improve the results.

Damage Effect of Shock Wave on Ventilation Structures during Gas Explosion

2010 ◽  
Vol 29-32 ◽  
pp. 118-124
Author(s):  
Zhi Ming Qu
Keyword(s):  
Numerical Simulation ◽  
Shock Wave ◽  
Low Cost ◽  
Ventilation System ◽  
Experimental Studies ◽  
Mine Ventilation ◽  
Damage Effect ◽  
Main Task ◽  
Gas Explosion ◽  
The Relationship

When the gas accumulation position, volume and concentration are basically determined, the gas explosion is ignited with the minimum ignition power. The main task is to study the damage effects by explosion shock wave on the roadway structures or barriers within the roadway. That the roadway and its ventilation structures are damaged will have an important impact on some lanes, mine ventilation system as well as the whole mine, which will influence the decision-making during disasters relief. As the experimental studies of damage effect by gas explosion is more difficult, therefore, the numerical simulation and analysis is important and useful. In conclusion, simulation can not only use low-cost way to reproduce gas explosion shock wave propagation and the damage of roadway structures, but also obtain the relationship between explosion damage effect and the volume and concentration.

Damage Mapping in Composites With Phase Gradient

2014 ◽  
Author(s):  
Aaron Darnton ◽  
Massimo Ruzzene
Keyword(s):  
Health Monitoring ◽  
Experimental Studies ◽  
Laminated Structure ◽  
Phase Gradient ◽  
Non Destructive Evaluation ◽  
Time Space ◽  
Recent Addition ◽  
Damage Mapping ◽  
Non Destructive ◽  
Gradient Approach

Lamb wave based methods for structural health monitoring and non-destructive evaluation have shown promise in composite and laminated structure applications. Many methods have been considered, but exploitation of the phase of the propagating wave is a recent addition. Utilizing the phase alleviates the ambiguity of many amplitude and modal analysis approaches. This paper considered two-dimensional damage analogs in analytical simulations, numerical simulations and experimental studies. Additionally, this paper addresses the importance of proper filtering for successful spatial domain reconstruction. The phase gradient approach was successful in cases where modal filtering yielded good results. In the case where modal filtering did not successfully reconstruct the time-space domain wave, the phase gradient approach could not be employed, underscoring the need for robust modal filtering techniques.

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