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Number of results: 70
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Abstract

Defects affect the properties and behavior of the casting during its service life. Since the defects can occur due to different reasons, they

must be correctly identified and categorized, to enable applying the appropriate remedial measures. several different approaches for

categorizing casting defects have been proposed in technical literature. They mainly rely on physical description, location, and formation

of defects. There is a need for a systematic approach for classifying investment casting defects, considering appropriate attributes such as

their size, location, identification stage, inspection method, consistency, appearance of defects. A systematic approach for categorization of

investment casting defects considering multiple attributes: detection stage, size, shape, appearance, location, consistency and severity of

occurrence. Information about the relevant attributes of major defects encountered in investment casting process has been collected from

an industrial foundry. This has been implemented in a cloud-based system to make the system freely and widely accessible.

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Authors and Affiliations

Amit V. Sata
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Abstract

In this study, an artificial neural network application was performed to tell if 18 plates of the same material in different shapes and sizes were cracked or not. The cracks in the cracked plates were of different depth and sizes and were non-identical deformations. This ANN model was developed to detect whether the plates under test are cracked or not, when four plates have been selected randomly from among a total of 18 ones. The ANN model used in the study is a model uniquely tailored for this study, but it can be applied to all systems by changing the weight values and without changing the architecture of the model. The developed model was tested using experimental data conducted with 18 plates and the results obtained mainly correspond to this particular case. But the algorithm can be easily generalized for an arbitrary number of items.

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Authors and Affiliations

Tahir Cetin Akinci
H. Selcuk Nogay
Ozgur Yilmaz
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Abstract

Metal casting process involves processes such as pattern making, moulding and melting etc. Casting defects occur due to combination of

various processes even though efforts are taken to control them. The first step in the defect analysis is to identify the major casting defect

among the many casting defects. Then the analysis is to be made to find the root cause of the particular defect. Moreover, it is especially

difficult to identify the root causes of the defect. Therefore, a systematic method is required to identify the root cause of the defect among

possible causes, consequently specific remedial measures have to be implemented to control them. This paper presents a systematic

procedure to identify the root cause of shrinkage defect in an automobile body casting (SG 500/7) and control it by the application of

Pareto chart and Ishikawa diagram. with quantitative Weightage. It was found that the root causes were larger volume section in the cope,

insufficient feeding of riser and insufficient poured metal in the riser. The necessary remedial measures were taken and castings were

reproduced. The shrinkage defect in the castings was completely eliminated.

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Authors and Affiliations

B. Chokkalingam
V. Raja
J. Anburaj
R. Immanual
M. Dhineshkumar
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Abstract

The rebuilding technologies are used to develop surface of ladle. Among many welding methods currently used to obtain surface layer

without defects one of the most effective way of rebuilding is using metal arc welding. This additional material gives more possibilities to

make expected quality of rebuild surface.

Chemical composition, property and economic factors allow to use metal wire. Because of these reasons, solid wire gives opportunity to be

wildly used as material to rebuild or repair the surface in different sectors of industry.

The paper shows a few ways to rebuild the surface in the massive cast with the use of metal active gas welding for repair. The work

presents studies of defect in the massive cast. It contains the pictures of microstructures and defects. The method of removing defects and

the results of checking by visual and penetrant testing methods are shown. The paper describes the methodology of repair the ladle with

metal active gas welding, preheating process and standards nondestructive testing method.

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Authors and Affiliations

R. Bęczkowski
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Abstract

The article contains basic information associated with the impact of the FSW process parameters on the forming of a weld while friction

welding of aluminium casting alloys. Research was conducted using specially made samples containing a rod of casting alloy mounted in

the wrought alloy in the selected area of FSW tool acting. Research has thrown light on the process of joining materials of significantly

dissimilar physical properties, such as casting alloys and wrought alloys. Metallographic testing of a weld area has revealed the big impact

of welding conditions, especially tool rotational speed, on the degree of metal stirring, grain refinement and shape factor of a weld. As the

result of research it has been stated that at the high tool rotational speed, the metals stirring in a weld is significantly greater than in case of

welding at low rotational speeds, however this fails to influence the strength of a weld. Plastic strain occurring while welding causes very

high refinement of particles in the tested area and changing of their shape towards particles being more equiaxial. In the properly selected

welding conditions it is possible to obtain joints of correct and repeatable structure, however in the case of the accumulation of cavities in

the casting alloy the FSW process not always eliminates them.

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Authors and Affiliations

A. Pietras
B. Rams
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Abstract

Nowadays, the best castings’ manufacturers have to meet very demanding requirements and specifications applicable to mechanical properties and other characteristics. To fulfill those requirements, more and more sophisticated methods are being used to analyze the internal quality of castings. In many cases, the commonly used Non-Destructive Methods, like X-ray or ultrasonic testing, are not enough to ensure precise and unequivocal evaluation. Especially, when the properties of the casting only slightly fail the specification and the reasons for such failures are very subtle, thus difficult to find without the modern techniques. The paper presents some aspects of such an approach with the use of Scanning Electron Microscopy (SEM) to analyze internal defects that can critically decrease the performance of castings. The paper presents the so-called bifilm defects in ductile and chromium cast iron, near-surface corrosion caused by sulfur, micro-shrinkage located under the risers, lustrous carbon precipitates, and other microstructure features. The method used to find them, the results of their analysis, and the possible causes of the defects are presented. The conclusions prove the SEM is now a powerful tool not only for scientists but it is more and more often present in the R&D departments of the foundries.
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Bibliography

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[2] Petrus, Ł., Bulanowski, A., Kołakowski, J., Brzeżański, M., Urbanowicz, M, Sobieraj, J., Matuszkiewicz, G., Szwalbe, L & Janerka, K. (2020). The influence of selected melting parameters on the physical and chemical properties of cast iron. Archives of Foundry Engineering. 1, 105-110. DOI: 10.24425/afe.2020.131290.
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[5] Kalandyk, B., Zapała, R., Sobula, S. & Tęcza, G. (2019). The effect of CaSiAl modification on the non-metallic inclusions and mechanical properties of low-carbon microalloyed cast steel. Archives of Foundry Engineering. 1, 47-52. DOI: 10.24425/afe.2018.125190.
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Authors and Affiliations

J. Jezierski
1
ORCID: ORCID
M. Dojka
1
M. Stawarz
1
ORCID: ORCID
R. Dojka
2

  1. Department of Foundry Engineering, Silesian University of Technology, 7 Towarowa, 44-100 Gliwice, Poland
  2. ODLEWNIA RAFAMET Sp. z o.o., 1 Staszica, 47-420 Kuźnia Raciborska, Poland
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Abstract

In pursuit of increased efficiency and longer operating times of photovoltaic systems, one may encounter numerous difficulties in the form of defects that occur in both individual solar cells and whole modules. The causes of the occurrence range from structural defects to damage during assembly or, finally, wear and tear of the material due to operation. This article provides an overview of modern imaging methods used to detect various types of defects found in photovoltaic cells and panels. The first part reviews typical defects. The second part of the paper reviews imaging methods with examples of the authors’ own test results. The article concludes with recommendations and tables that provide a kind of comprehensive guide to the methods described, depending on the type of defects detected, the range of applicability, etc. The authors also shared their speculations on current trends and the possible path for further development and research in the field of solar cell defect analysis using imaging.
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Authors and Affiliations

Maurycy Maziuk
1
Laura Jasińska
1
Jarosław Domaradzki
1
Paweł Chodasewicz
1

  1. Wrocław University of Science and Technology, Faculty of Electronic, Photonics and Microsystems, Department ofElectronic and Photonic Metrology, Division of Thin Film Technologies, Wybrzeze Wyspianskiego 27, 50-370 Wrocław,Poland
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Abstract

The authors developed the definition of construction defect and fault and construction defect management based on Polish and foreign publications. In order to assist identification of faults and their analysis in the process of home collection, the authors applied the Case Based Reasoning (CBR) method. In the paper, the authors used Case Based Reasoning (CBR) to support acceptance of apartments. The CBR method allows to determine the magnitude of global similarity for the problem under consideration between the new and old case from the Case Base, using weighted sums of local similarities using criteria weights as coefficients. As a result of CBR-based solutions, an Employer’s representative receives information about the type of construction defects that can be expected, their location and significance, occurrence frequency, and estimated repair cost.

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Authors and Affiliations

K. Zima
S. Biel
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Abstract

In this study, it was achieved by using the method of impulse noise to detect internal or surface cracks that can occur in the production of ceramic plates. Ceramic materials are often used in the industry, especially as kitchenware and in areas such as the construction sector. Many different methods are used in the quality assurance processes of ceramic materials. In this study, the impact noise method was examined. This method is a test technique that was not used in applications. The method is presented as an examination technique based on whether there is a deformation on the material according to the sound coming from it as a result of a plastic bit hammer impact on the ceramic material. The application of the study was performed on plates made of ceramic materials. Here, it was made with the same type of model plates manufactured from the same material. The noise that would occur as a result of the impact applied on a point determined on the materials to be tested has been examined by the method of time-frequency analysis. The method applied gives pretty good results for distinguishing ceramic plates in good condition from those which are cracked.

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Authors and Affiliations

Tahir Akinci
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Abstract

The article describes the detection of a defect in a cast iron casting. It analyzes the cause of the crack in the Turbine Component casting. In this article, we are focusing on a particular turbine casting that is commonly used in automobiles as one of the components for turbochargers. The turbine is a casting made of ductile cast iron with a visible crack on the naked eye. The formation of cracks in castings is a common but undesirable phenomenon in the foundry practice. It is important to identify the errors, but also to know the cause of defects in castings. The solution is a detailed error analysis. In this paper I used metallographic analysis and magnetic powder method. The crack formation is due to tension in the casting, which results in tensile, shear, or shear forces. The crack formation kinetics is difficult because it is still very low during hardening and shortly after the casting is overloaded. The crack is most often due to core resistance or shrinkage molds that begin after the surface layer is tightened when the strength of the material is negligible to the end of the crystallisation.

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Authors and Affiliations

E. Kantoríková
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Abstract

The conducted work shows and confirms how thermal analysis of grey and ductile iron is an important source for calculating metallurgical data to be used as input to increase the precision in simulation of cooling and solidification of cast iron. The aim with the methodology is to achieve a higher quality in the prediction of macro– and micro porosity in castings. As comparison objects standard type of sampling cups for thermal analysis (solidification module M ≈ 0.6 cm) is used. The results from thermal analysis elaborated with the ATAS MetStar system are evaluated parallel with the material quality (including tendency to external and internal defects) of the tested specimen. Significant temperatures and calculated quality parameters are evaluated in the ATAS MetStar system and used as input to calibrate the density curve as temperature function in NovaFlow&Solid simulation system. The modified data are imported to the NovaFlow&Solid simulation system and compared with real results.

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Authors and Affiliations

P-E. Persson
Z. Ignaszak
H. Fransson
V. Kropotkin
R. Andersson
A. Kump
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Abstract

The Mg-RE alloys are attractive, constructional materials, especially for aircraft and automotive industry, thanks to combination of low density, good mechanical properties, also at elevated temperature, and good castability and machinability. Present paper contains results of fatigue resistance test carried out on Elektron 21 magnesium alloy, followed by microstructural and fractographical investigation of material after test. The as-cast material has been heat treated according to two different procedures. The fatigue resistance test has been conducted with 106 cycles of uniaxial, sine wave form stress between 9 MPa and 90 MPa. Fractures of specimens, which ruptured during the test, have been investigated with scanning electron microscope. The microstructure of specimens has been investigated with light microscopy. Detrimental effect of casting defects, as inclusions and porosity, on fatigue resistance has been proved. Also the influence of heat treatment's parameters has been described.
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Authors and Affiliations

I. Pikos
J. Adamiec
A. Kiełbus
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Abstract

The main bulk density representation in the molding material is opening material, refractory granular material with a particle size of 0.02

mm. It forms a shell molds and cores, and therefore in addition to activating the surface of the grain is one of the most important features

angularity and particle size of grains. These last two features specify the porosity and therefore the permeability of the mixture, and

thermal dilatation of tension from braking dilation, the thermal conductivity of the mixture and even largely affect the strength of molds

and cores, and thus the surface quality of castings. [1]

Today foundries, which use the cast iron for produce of casts, are struggling with surface defects on the casts. One of these defects are

veining. They can be eliminated in several ways. Veining are foundry defects, which arise as a result of tensions generated at the interface

of the mold and metal. This tension also arises due to abrupt thermal expansion of silica sand and is therefore in the development of

veining on the surface of casts deal primarily influences and characteristics of the filler material – opening material in the production of

iron castings.

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Authors and Affiliations

M. Hrubovčáková
M. Conev
I. Vasková
M. Benková
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Abstract

In the paper a method using active thermography and a neural algorithm for material defect characterization is presented. Experimental investigations are conducted with the stepped heating method, so-called time-resolved infrared radiometry, for the test specimen made of a material with low thermal diffusivity. The results of the experimental investigations were used in simulations of artificial neural networks. Simulations are performed for three datasets representing three stages of the heating process occurring in the investigated sample. In this work, the simulation research aimed to determine the accuracy of defect depth estimation with the use of the mentioned algorithm is descibed

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Authors and Affiliations

Sebastian Dudzik
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Abstract

Due to the wide range of various sheet metal grades and the need to verify the material properties, there are numerous methods to determine the material formability. One of them, that allows quick determination of sheet metal formability, is the Erichsen cupping test described in the ISO 20482: 2003 standard. In the presented work, the results of formability assessment for DC04 deep drawing sheet metal were obtained by means of the traditionally carried out Erichsen cupping test and compared with the results obtained by using two advanced methods based on vision analysis. Application of these methods allows extending the traditional scope of analysis during Erichsen cupping test by determination of the necking and strain localization before fracture. The proposed methods were compared in order to dedicate appropriate solution for the industrial application and laboratory tests respectively, where the simplicity and reliability are the mean aspects need to be considered when applied to the Erichsen cupping test.

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Authors and Affiliations

C. Jasiński
S. Świłło
A. Kocańda
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Abstract

Effect of annealing on the structural properties of arsenic-implanted mercury cadmium telluride film grown by molecular beam epitaxy was studied with the use of transmission electron microscopy and optical reflection. Strong influence of the graded-gap surface layer grown on top of the film on the behaviour of implantation-induced defects under arsenic activation annealing was revealed and interpreted.

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Authors and Affiliations

I.I Izhninab
O.I. Fitsych
Z. Świątek
Y. Morgiel
O.Yu. Bonchyk
H.V. Savytskyy
K.D. Mynbaev
A.V. Voitsekhovskii
A.G. Korotaev
M.V. Yakushev
V.S. Varavin
S.A. Dvoretsky
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Abstract

The work concerns of modeling the process of manufacturing machine parts by casting method. Making a casting without internal defects is a difficult task and usually requires numerous computer simulations and their experimental verification at the prototyping stage. Numerical simulations are then of priority importance in determining the appropriate parameters of the casting process and in selecting the shape of the riser for the casting fed with it. These actions are aimed at leading shrinkage defects to the riser, so that the casting remains free from this type of defects. Since shrinkage defects usually disqualify the casting from its further use, this type of research is still valid and requires further work. The paper presents the mathematical model and the results of numerical simulations of the casting solidification process obtained by using the Finite Element Method (FEM). A partial differential equation describing the course of thermal phenomena in the process of 3D casting creating was applied. This equation was supplemented with appropriate boundary and initial conditions that define the physical problem under consideration. In numerical simulations, by selecting the appropriate shape riser, an attempt was made to obtain a casting without internal defects, using a simple method of identifying their location. This is the main aim of the research as such defects in the casting disqualify it from use.
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Authors and Affiliations

L. Sowa
1
ORCID: ORCID
T. Skrzypczak
1
ORCID: ORCID
P. Kwiatoń
1
ORCID: ORCID

  1. Czestochowa University of Technology, Department of Mechanics and Machine Design Fundamentals, Dąbrowskiego 73, 42-200 Częstochowa, Poland
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Abstract

CVM ( Complex Vertebral Malformations) and Brachyspina (BY) are the most common autosomal recessive genetic defects occurring in the last two decades in Holstein dairy cattle around the world. Beginning from 2004 and 2014, 3035 and 338 Polish Holstein-Friesian bulls were tested to find carriers of CVM and BY, respectively. Among analyzed bulls 191 CVM carriers (6.29%) and 20 BY carriers (5.92%) were identified. No CVM carriers were observed beginning from 2016, whereas only single BY carriers was identified annually for the last 5 years. One bull turned to be double CVM/ BY carrier as a son of also double CVM/BY top Dutch sire (JABOT 90676-4-9). It is shown that CVM and BY defects are practically eradicated from Polish dairy cattle although incidental testing should be continued if new bulls with CVM or BY carriers in sire or dam pedigree will unexpectedly appear.
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Authors and Affiliations

S. Kamiński
1

  1. University of Warmia and Mazury, Department of Animal Genetics, Faculty of Animal Bioengineering, Oczapowskiego 5, 10-719 Olsztyn, Poland
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Abstract

The objective of this work is to gain a deeper understanding of the separation effects and particle movement during filtration of non-metallic inclusions in aluminum casting on a macroscopic level. To understand particle movement, complex simulations are performed using Flow 3D. One focus is the influence of the filter position in the casting system with regard to filtration efficiency. For this purpose, a real filter geometry is scanned with computed tomography (CT) and integrated into the simulation as an STL file. This allows the filtration processes of particles to be represented as realistically as possible. The models provide a look inside the casting system and the flow conditions before, in, and after the filter, which cannot be mapped in real casting tests. In the second part of this work, the casting models used in the simulation are replicated and cast in real casting trials. In order to gain further knowledge about filtration and particle movement, non-metallic particles are added to the melt and then separated by a filter. These particles are then detected in the filter by metallographic analysis. The numerical simulations of particle movement in an aluminum melt during filtration, give predictions in reasonable agreement with experimental measurements.
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Bibliography

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Authors and Affiliations

B. Baumann
1
A. Keßler
1
E. Hoppach
1
G. Wolf
1
M. Szucki
1
ORCID: ORCID
O. Hilger
2

  1. Foundry Institute, Technische Universität Bergakademie Freiberg, 4 Bernhard-von-Cotta-Str., 09599 Freiberg, Germany
  2. Simcast GmbH, Westring 401, 42329 Wuppertal, Germany
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Abstract

In our study, we estimated the frequency of haplotype for cholesterol deficiency (HCD) carriers in the Russian Holstein cattle population. We studied 1817 random samples of cows born in 2010-2017 from ten herds and 331 cows and heifers from the other three herds born in 2016-2019, fathers or fathers of mothers of which were HCD carriers. The method of AS-PCR was used for animals genotyping. In the first group of animals, the incidence of HCD carriers was 8.09%, and in the second one - 23.26%. Our results demonstrated the necessity to test cows for the carriage of the HCD genetic defect in the Russian population of Holstein cattle.

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Authors and Affiliations

M.V. Pozovnikova
E.A. Gladyr
O.S. Romanenkova
O.K. Vasileva
V.B. Leibova
V.I. Tyshchenko
N.V. Dementeva
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Abstract

This article discusses the performance of an algorithm for detection of defect centers in semiconductor materials. It is based on direct parameter approximation with nonlinear regression to determine the parameters of thermal emission rate in the photocurrent waveforms. The methodology of the proposed algorithm was presented and its application procedure was described and the results of its application can be seen in measured photocurrent waveforms of a silicon crystal examined with High-Resolution Photoinduced Transient Spectroscopy (HRPITS). The performance of the presented algorithm was verified using simulated photocurrent waveforms without and with noise at the level of 10 -2. This paper presents for the first time the application of the direct approximation method using modern regression and clustering algorithms for the study of defect centers in semiconductors.
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Authors and Affiliations

Witold Kaczmarek
1
Marek Suproniuk
1
Karol Piwowarski
1
Bogdan Perka
1
Piotr Paziewski
1

  1. Institute of Electronic Systems, Department of Electronics, Military University of Technology, ul. gen. Sylwestra Kaliskiego 2, 00-908 Warszawa, Poland
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Abstract

A group of old apartment houses with the age over 100 years (that is those carried out before the First World War) takes an important place in polish building resources. Technical maintenance of apartment houses, traditional methods erected, is nowadays and will be a valid problem in the nearest future. The results of the work refer to the general population, estimated for 600 objects, that is about 20% of municipal downtown apartment houses in Wrocław.

The purpose of the research was to identify an influence of widely considered maintenance of apartment houses on a degree and intensity of their elements’ deterioration. The goal of the work has been fulfilled by symptoms’ analysis of declining of inspected elements’ exploitation values, that is identification of mechanics of their defects arising.

The range of the work has required creation of original qualitative model of pinpointed defects and its transfer into quantitative one. It has made possible to analyse the reason - effect phenomena „defect - technical wear” relevant to the most important elements of Wroclaw downtown district’s apartment houses. The research procedure has been conducted in accordance of fuzzy sets theory which made possible to describe qualitative model of pinpointed defects and its transfer into a quantitative one.

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Authors and Affiliations

J. Konior
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Abstract

Hundreds or even thousands of defects can be found during the building acceptance, hence the need for solutions which will facilitate the defect management, including identification, costing and repair. The aim of the paper is to present the possible use of BIM to support the defect management process during the acceptance of apartments in multifamily residential buildings. The paper presents a concept of quality control support application called MWBIM (Map of Knowledge BIM) which will collect data about discovered construction defects, their recording and servicing with the BIM technology. MWBIM will run based on Building Information Modelling (BIM), Augmented Reality (AR), Case-Based Reasoning (CBR) and maps of knowledge. There are three phases in the operation of the application: preparatory phase (planning the order of acceptance meetings and elements to be checked), acceptance phase (data collection and assigning them to the building information model) and the reporting phase (reports generation, assigning defects to contractors, follow-up of repair status). The intended uses of the application are mainly personnel involved in the acceptance of apartments.
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Authors and Affiliations

Sebastian Biel
1
ORCID: ORCID

  1. MSc., Eng., Cracow University of Technology, Faculty of Civil Engineering, Division of Management in Civil Engineering (L-7), Warszawska 24 Street, 31-155 Cracow, Poland
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Abstract

This work deals with the inverse problem associated to 3D crack identification inside a conductive material using eddy current measurements. In order to accelerate the time-consuming direct optimization, the reconstruction is provided by the minimization of a last-square functional of the data-model misfit using space mapping (SM) methodology. This technique enables to shift the optimization burden from a time consuming and accurate model to the less precise but faster coarse surrogate model. In this work, the finite element method (FEM) is used as a fine model while the model based on the volume integral method (VIM) serves as a coarse model. The application of the proposed method to the shape reconstruction allows to shorten the evaluation time that is required to provide the proper parameter estimation of surface defects.

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Authors and Affiliations

Piotr Putek
Guillaume Crevecoeur
Marian Slodička
Konstanty Gawrylczyk
Roger van Keer
Luc Dupré

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