scholarly journals A comparative study of optimization methods for eddy-current characterization of aeronautical metal sheets

2021 ◽  
Vol 34 (4) ◽  
pp. 547-555
Author(s):  
Ben Moussa Oum Salama ◽  
Ayad Ahmed Nour El Islam ◽  
Tarik Bouchala
Keyword(s):  
Eddy Current ◽  
Simplex Method ◽  
Particle Swarm ◽  
Optimization Methods ◽  
304L Stainless Steel ◽  
Swarm Algorithms ◽  
Metal Sheets ◽  
Aeronautical Industry ◽  
Non Destructive

This paper presents eddy current non-destructive characterization of three aeronautical metal sheets by deterministic and stochastic inversion methods. This procedure consists of associating the finite element method with three optimization algorithms (Simplex method and genetic and particle swarm algorithms) simultaneously determine electric conductivity, magnetic permeability and thickness of Al, Ti and 304L stainless steel metal sheets largely used in aeronautical industry. Indeed, the application of these methods has shown the performance of each inversion algorithms. As a result, while doing a qualitative and quantitative comparison, it was found that the Simplex method is more advantageous in comparison with genetic and particle swarm algorithms, since it is faster and more stable .

Mechanical Characterization of Metal Sheets by Means of Double Indentation

2007 ◽  
Vol 344 ◽  
pp. 127-134 ◽  
Author(s):  
Fabrizio Quadrini ◽  
Loredana Santo ◽  
Erica Anna Squeo
Keyword(s):  
Small Diameter ◽  
Tensile Tests ◽  
Testing Rate ◽  
Metal Sheets ◽  
Indentation Tests ◽  
Tensile Data ◽  
On Line ◽  
Fast Procedure ◽  
Non Destructive

An easy and innovative technique for metal sheet characterization is described. A double indentation is performed on sheets by means of two co-axial small diameter flat indenters made of WC. A very small indentation is left on the sheet, so as to consider this technique a non destructive one, particularly suitable for on-line application. The proposed method was tested on sheets of aluminum alloy (6082 T6) with several thicknesses (nominally 0.6, 0.8, 1 and 1.5 mm). Double indentations were performed changing indenter diameter (1 and 2 mm) and testing rate (from 0.05 to 1 mm/min). In order to make a comparison with indentation tests, flat specimens were cut from the same sheets and standard tensile tests were performed. A very good correlation was found between indentation and tensile test results, showing the effectiveness of the proposed method. A suitable data normalization is necessary to correctly compare indentation and tensile data. The best results were obtained using the smaller diameter indenter. The testing rate seems to be not relevant in the experimented range, suggesting that a fast procedure can be defined on purpose for on-line application.

CHARACTERIZATION OF FRICTION WELDED TITANIUM ALLOY AND STAINLESS STEEL WITH A NOVEL INTERLAYER GEOMETRY

2016 ◽  
Vol 24 (05) ◽  
pp. 1750064
Author(s):  
R. KUMAR ◽  
M. BALASUBRAMANIAN
Keyword(s):  
Stainless Steel ◽  
Research Work ◽  
Metal Loss ◽  
304L Stainless Steel ◽  
Surface Geometry ◽  
Optical Micrograph ◽  
Minimum Number ◽  
Novel Method ◽  
Non Destructive

The main purpose of the current research work is to identify and investigate a novel method of holding an intermediate metal and to evaluate its metallurgical and mechanical properties. Copper was used as an interlayer material for the welding of this dissimilar Ti–6Al–4V (Ti alloy) and 304L stainless steel (SS). The study shows that the input parameters and surface geometry played a very significant role in producing a good quality joints with minimum heat affected zone and metal loss. A sound weld was achieved between Ti–6Al–4V and SS304L, on the basis of the earlier experiments conducted by the authors in their laboratory, by using copper rod as intermediate metal. Box–Behnken method was used for performing a minimum number of experiments for the study. In the present study, Ti–6Al–4V alloy and SS304L were joined by a novel method of holding the interlayer and new surface geometry for the interlayer. Initially, the drop test was used for determining the quality of the fabricated joint and, subsequently, non-destructive techniques like radiography and C-scan were used. Further optical micrograph, SEM–EDS, hardness and tensile test were done for understanding the performance of the joint.

Characterization of the Wear in the Turbojet Fins

2015 ◽  
Vol 640 ◽  
pp. 29-34
Author(s):  
Zohra Labed ◽  
Djamel Guechi ◽  
Necib Brahim
Keyword(s):  
Fatigue Damage ◽  
Eddy Current ◽  
Non Destructive ◽  
Non Destructive Techniques

The wear is very difficult to characterize because of its complexity and its measurement phenomenon. Our work is to prepare samples Fan blades, worn, to determine the nature of the wear and damage them. For these reasons, the characterization of these samples was conducted in different microscopic and macroscopic scales. We used non-destructive techniques such as eddy current and penetrant methods. The results obtained allowed us to see the deterioration of fins from one floor to another. These results are directly related to the effects of mechanical, thermal and pressure. It has been, in addition to detecting a different type of damage these fan blades that is the fatigue damage.

scholarly journals Feature selection with acquisition cost for optimizing sensor system design

2006 ◽  
Vol 4 ◽  
pp. 135-141 ◽  
Author(s):  
K. Iswandy ◽  
A. Koenig
Keyword(s):  
Signal Processing ◽  
Feature Selection ◽  
Acquisition Cost ◽  
Particle Swarm ◽  
Optimization Methods ◽  
Convergence Time ◽  
Sensor Technology ◽  
Particle Swarm Algorithm ◽  
Swarm Algorithms ◽  
Selection Of Variables

Abstract. Selection of variables from large sets of measurements is a common problem of data analysis and signal processing in many disciplines. In engineering and sensor technology the design of recognition systems can be optimized by judicious choice of subsets of relevant features. In particular, the effort required for signal processing and sensor registration can be considerably reduced by efficient feature selection. However, the current approaches in majority only consider the contribution of features or measurements to the classification ability of the system. The associated cost in terms of computation effort, the required electronics, and power dissipation is not explicitly in consideration. This paper proposes a multi-objective extension of feature selection including acquisition cost and employing and comparing two evolutionary optimization methods. The genetic and particle swarm algorithms and the results achieved with selected data sets will be presented. The results show, that particle swarm algorithm can select best features with lower cost and achieve more competitive results with regard to convergence time and classification accuracy than genetic algorithm.

Qualification of a Frequency Scanning Eddy Current Equipment for Nondestructive Characterization of New and Serviced High-Temperature Coatings

2001 ◽  
Author(s):  
Giampiero Antonelli ◽  
Paola Crisafulli ◽  
Giacomo Tirone
Keyword(s):  
High Temperature ◽  
Eddy Current ◽  
Gas Turbines ◽  
Structural Damage ◽  
Economic Losses ◽  
Thermal Barriers ◽  
Frequency Scanning ◽  
Non Destructive ◽  
Equipment Qualification

As modern gas turbines are continuously being upgraded, mainly through the increase of their firing temperature and cooling optimization, the prime protection of the high technology and high-cost hot gas path parts is increasingly being transferred to the coatings. In order to avoid the risk of structural damage of these components, with its potential for greater economic losses — mostly traceable to unexpected prime time outages — refurbishment cycle should be dictated by the amount of the life actually expended by the coating. To address the issues of quality and condition assessment of new and serviced high-temperature coatings applied on buckets and vanes, an innovative non-destructive system was developed based on a frequency scanning eddy current technique. It combines outstanding high frequency hardware with model based analysis of raw data. In the paper, quantitative data on equipment qualification are presented, relating to its capability in measuring both the thickness and β-aluminide depletion of MCrAlY coatings applied on Ni-base superalloys. The results of an inspection campaign on serviced blades, performed during major overhauls of ENEL gas turbines, will also be reported, together with recent system upgrades, aiming at extending its applicability to newer coatings such as thermal barriers and over-aluminized MCrAlY’s.

Application of rogue algorithms in the WLAN planning task

2017 ◽  
Vol 4 (3) ◽  
pp. 99-110
Author(s):  
Adam Piperzycki ◽  
Wiesław Ludwin
Keyword(s):  
Wireless Networks ◽  
Particle Swarm ◽  
Optimization Methods ◽  
Criterion Function ◽  
Swarm Optimization ◽  
Swarm Algorithms ◽  
Indoor Wireless ◽  
Planning Task

The aim of this article is to examine and compare swarm optimization methods in the task of planning indoor wireless networks (WLAN). For this purpose, in the process of searching for the extremum of the criterion function, which is an optimization indicator, six swarm algorithms were used: artificial bees colony, bat, bee, cuckoo, firefly, particle swarm (bird).

Characterization of aging behaviour in M250 grade maraging steel using eddy current non-destructive methodology

2007 ◽  
Vol 464 (1-2) ◽  
pp. 233-240 ◽  
Author(s):  
K.V. Rajkumar ◽  
B.P.C. Rao ◽  
B. Sasi ◽  
Anish Kumar ◽  
T. Jayakumar ◽  
...  
Keyword(s):  
Maraging Steel ◽  
Eddy Current ◽  
Non Destructive
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