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1

COVID-19 detection on chest X-ray images using Homomorphic Transformation and VGG inspired deep convolutional neural network

Shibu George Gerosh, Raj Mishra Pratyush, Sinha Panav, Ranjan Prusty Manas

Biocybernetics and Biomedical Engineering

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2023

|

Vol. 43., no. 1

1--16

EN

COVID-19 had caused the whole world to come to a standstill. The current detection methods are time consuming as well as costly. Using Chest X-rays (CXRs) is a solution to this problem, however, manual examination of CXRs is a cumbersome and difficult process needing specialization in the domain. Most of existing methods used for this application involve the usage of pretrained models such as VGG19, ResNet, DenseNet, Xception, and EfficeintNet which were trained on RGB image datasets. X-rays are fundamentally single channel images, hence using RGB trained model is not appropriate since it increases the operations by involving three channels instead of one. A way of using pretrained model for grayscale images is by replicating the one channel image data to three channel which introduces redundancy and another way is by altering the input layer of pretrained model to take in one channel image data, which comprises the weights in the forward layers that were trained on three channel images which weakens the use of pre-trained weights in a transfer learning approach. A novel approach for identification of COVID-19 using CXRs, Contrast Limited Adaptive Histogram Equalization (CLAHE) along with Homomorphic Transformation Filter which is used to process the pixel data in images and extract features from the CXRs is suggested in this paper. These processed images are then provided as input to a VGG inspired deep Convolutional Neural Network (CNN) model which takes one channel image data as input (grayscale images) to categorize CXRs into three class labels, namely, No-Findings, COVID-19, and Pneumonia. Evaluation of the suggested model is done with the help of two publicly available datasets; one to obtain COVID-19 and No-Finding images and the other to obtain Pneumonia CXRs. The dataset comprises 6750 images in total; 2250 images for each class. Results obtained show that the model has achieved 96.56% for multi-class classification and 98.06% accuracy for binary classification using 5-fold stratified cross validation (CV) method. This result is competitive and up to the mark when compared with the performance shown by existing approaches for COVID-19 classification.

2

A new tooling approach for friction stir welding of thin sheet AA2024-T3 - optimization of welding parameters

Myśliwiec Piotr

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

|

2022

|

z. 94

37--50

EN

In this study a new ceramics tools with different groove distributions were designed and manufactured in order to enrich technological storage of joining thinwall structures and obtain sound joint with high quality of Alclad AA2024-T3 alloy of 0.5 mm in thickness. Four types of tools were tested, without grooves, with 1, 2 and 6 grooves. The tools are made of two materials. The straight shank is made from tungsten carbide and tool body made from ceramics strengthened with whiskers. The influence of technological parameters on the strength of FSW joints was tested by the Response Surface Methodology (RSM) and Analysis of Variance (ANOVA) method. The least durable weld is produced by a tool without grooves. The single and double flute tool produces a good quality weld over a wide range of tool speeds. It has been shown that the grooves on the tool shoulder significantly affect the quality of the obtained FSW joint.

PL

W pracy zaprojektowano i wykonano nowe narzędzia ceramiczne o różnym rozkładzie rowków w celu wzbogacenia technologii łączenia konstrukcji cienkościennych i uzyskania wysokiej jakości połączenia blach ze stopu aluminium AA2024-T3 Alclad o grubości 0,5 mm. Przetestowano cztery typy narzędzi, bez rowków, z 1, 2 i 6 rowkami. Narzędzia wykonano z dwóch materiałów. Część chwytową wykonano z węglika wolframu, a korpus narzędzia z ceramiki wzmocnionej whiskerami. Wpływ parametrów technologicznych na wytrzymałość złączy FSW badano metodami analizy powierzchni odpowiedzi (RSM) oraz analizy wariancji (ANOVA). Najmniej trwałą spoinę wytworzyło narzędzie bez rowków. Narzędzie z pojedynczym i podwójnym rowkiem zapewniło dobrej jakości spoinę w szerokim zakresie prędkości obrotowych narzędzia. Wykazano, że rowki na kołnierzu narzędzia istotnie wpływają na jakość uzyskanego połączenia FSW.

3

Zero Defect Manufacturing Using Digital Numerical Control

Ly Duc Minh, Bilik Peter

Management and Production Engineering Review

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2022

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Vol. 13, No. 3

61--74

EN

This paper proposes the application of the digital numerical control (DNC) technique to connect the smart meter to the inspection system and evaluate the total harmonic distortion (THD) value of power supply voltage in IEEE 519 standard by measuring the system. Experimental design by the Taguchi method is proposed to evaluate the compatibility factors to choose Urethane material as an alternative to SS400 material for roller fabrication at the machining center. Computer vision uses artificial intelligence (AI) technique to identify object iron color in distinguishing black for urethane material and white for SS400 material, color recognition results are evaluated by measuring system, system measurement is locked when the object of identification is white material SS400. Computer vision using AI technology is also used to recognize facial objects and control the layout of machining staff positions according to their respective skills. The results obtained after the study are that the surface scratches in the machining center are reduced from 100% to zero defects and the surface polishing process is eliminated, shortening production lead time, and reducing 2 employees. The total operating cost of the processing line decreased by 5785 USD per year. Minitab 18.0 software uses statistical model analysis, experimental design, and Taguchi technical analysis to evaluate the process and experimentally convert materials for roller production. MATLAB 2022a runs a computer vision model using artificial intelligence (AI) to recognize color objects to classify Urethane and SS400 materials and recognize the faces of people who control employee layout positions according to their respective skills.

4

Modeling and optimization of cutting parameters when turning EN-AW-1350 aluminum alloy

Khrouf F., Tebassi H., Yallese M. A., Chaoui K., Haddad A.

International Journal of Applied Mechanics and Engineering

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2022

|

Vol. 27, no. 2

124--142

EN

An experimental investigation is carried out to examine the effects of various cutting parameters on the response criteria when turning EN-AW-1350 aluminum alloy under dry cutting conditions. The experiments related to the analysis of the influence of turning parameters on the surface roughness (Ra) and material removal rate (MRR) were carried out according to the Taguchi L27 orthogonal array (313) approach. The analysis of variance (ANOVA) was applied to characterizing the main elements affecting response parameters. Finally, the desirability function (DP) was applied for a bi-objective optimization of the machining parameters with the objective of achieving a better surface finish (Ra) and a higher productivity (MRR). The results showed that the cutting speed is the most dominant factor affecting Ra followed by the feed rate and the depth of cut. Moreover, the Artificial Neural Network (ANN) approach is found to be more reliable and accurate than its Response Surface methodology (RSM) counterpart in terms of predicting and detecting the non-linearity of the surface roughness and material removal rate mathematical models. ANN provided prediction models with a precision benefit of 8.21% more than those determined by RSM. The latter is easier to use, and provides more information than ANN in terms of the impacts and contributions of the model terms.

5

A simplistic regression-based genetic algorithm optimization of tool-work interface temperature

Utkarsh, Kumar Saumya, Kumar Saaransh, Kiran G. Uday, Mukhopadhyay Arkadeb, Barman Manik

Engineering Transactions

|

2022

|

Vol. 70, iss. 2

141--156

EN

This work aims to investigate the average tool-work interface temperature for the HSS tool and AISI 1040 steel pair. A tool-work thermocouple is proposed for the measurement of temperature because of its simple construction in addition to the low cost. The machining process of AISI 1040 steel is considered due to its extensive application, including industry usage. The changes in cutting temperature are studied for combinations of cutting speed, feed and the depth of cut during turning operation. The orthogonal array L9 by Taguchi is adopted for designing the experiments within a restricted set of runs. The average cutting temperature shows an increasing curve with functions of speed versus depth of cut and speed versus feed. But no clear trend is observed for a combination of feed versus depth of cut. A second-order regression equation with reasonable accuracy (R 2 = 0.99) is fitted using the data. Analysis of variance (ANOVA) reveals the highest contribution from cutting speed, which influences average temperature at the interface of tool and work. Further, the genetic algorithm predicts an optimal combination of parameters, which is 82.542 m/min cutting speed, 0.276 mm/rev feed rate and 0.2 mm depth.

6

Modeling and prediction of thermal conductivity ratio of metal-oxide based nano-fluids using artificial neural network and power law

Hanief Mohammad, Irfan Quresh, Parvez Malik

Chemical and Process Engineering

|

2022

|

Vol. 43, nr 2

159–-163

EN

In this study, the thermal conductivity ratio model for metallic oxide based nano-fluids is proposed. The model was developed by considering the thermal conductivity as a function of particle concentration (percentage volume), temperature, particle size and thermal conductivity of the base fluid and nano-particles. The experimental results for Al2O3, CuO, ZnO, and TiO2 particles dispersed in ethylene glycol, water and a combination of both were adopted from the literature. Artificial neural network (ANN) and power law models were developed and compared with the experimental data based on statistical methods. ANOVA was used to determine the relative importance of contributing factors, which revealed that the concentration of nano-particles in a fluid is the single most important contributing factor of the conductivity ratio.

7

Assessment of evidence based climate variability in Bhagirathi sub basin of India: a geostatistical analysis

Rehman Sufa, Sajjad Haroon, Masroor Md, Rahaman Md Hibjur, Roshani, Ahmed Raihan, Sahana Mehebub

Acta Geophysica

|

2022

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Vol. 70, no 1

445--463

EN

Climate variability analysis is essential for predicting the behavior of various extreme weather events and making communities resilient. Notwithstanding the profound concerns, climate variability assessment faces numerous challenges due to inadequate and sometimes unavailability of data at spatiotemporal scales. This study makes an attempt to analyse climate variability in the Bhagirathi Sub-basin of India. Six meteorological variables were analysed from fourteen weather stations located in the Sub-basin during 1968–2017. Modified Mann–Kendall test was employed to ascertain the trends in meteorological variables. One-way ANOVA was used to assess the relationship between and within the variables. A total of 432 households were selected for reaffirming climate variability and impact on landscape. Significant trends were detected in highest maximum, mean maximum (Mmax) and mean minimum (Mmin) temperatures, relative humidity (Rh), rainfall and vapour pressure (Vp) at annual and seasonal scales. Stations located in eastern and deltaic Sub-basins registered varying trends in these meteorological variables due to anthropogenic activities-induced land use changes. ANOVA revealed a robust relation among rainfall, Vp, Mmin and Mmax. Perceptions of the sampled households revealed that climate variability has considerably affected food intensity, vegetation, soil, water resources and agricultural pattern. We find modified Mann– Kendall method effective in analysing climate variability in the Sub-basin. Thus, this method can be utilized for effective analysis of climate variability at spatial scales in geographical regions.

8

The influence of ball milling processing variables on the microstructure and compaction behavior of Fe–Mn–Cu alloys

Ammar Hany R., Sivasankaran Subbarayan, Alaboodi Abdulaziz S.

Materials Science Poland

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2021

|

Vol. 39, No. 3

410--429

EN

In the present study, twenty seven [(Fe–35wt%Mn)100−x–Cux] alloy samples were processed using high-energy ball milling, followed by uniaxial compaction under different processing conditions. The compressibility behavior in terms of relative density (RD) was examined with milling time (MT: 1 h, 5.5 h, and 10 h), ball-to-powder mass ratio (BPMR: 5:1, 10:1, and 15:1), milling speed (MS: 100 rev/min, 200 rev/min, and 300 rev/min), compaction pressure (CP: 25–1,100 MPa), and alloy composition (Cu content [CC]: 0 wt%, 5 wt%, 10 wt%). Particle size analysis using X-ray diffraction (XRD) and high-resolution scanning electron microscopy (HRSEM) combined with energy-dispersive X-ray spectroscopy (EDS) were applied for microstructural characterization. The experiments were conducted based on the central composite design of response surface methodology (RSM), and the results for the compaction behavior were examined with the input parameters. Analysis of variance (ANOVA) test was applied to determine the most significant input parameters. The attained results revealed that increasing ball milling parameters (MT, MS, and BPMR) resulted in significant enhancements in the microstructural features, such as improved elemental dispersion and occurrence of refined particles with substantial decrease in the crystallite size. On the other hand, increasing the input parameters exhibited a detrimental influence on the compactibility and RD of the alloys. In addition, increasing the CC resulted in a substantial improvement in the compressibility and RD of the developed alloys. The recommended combination of the studied variables includes MT for 5 h, MS for 150 rev/min, BPMR of 10:1, and 10 wt%Cu to attain an acceptable compromise of enhanced microstructure features, improved compaction response, and RD.

9

Characterisation of CVC Yarn with Different Drafting Ratios in Vortex Spinning

Repon Md. Reazuddin, Islam Tarikul, Rahman Mahbubur, Malek Md. Abdul, Jalil Mohammad Abdul

Fibres & Textiles in Eastern Europe

|

2021

|

Nr 6 (150)

54--58

EN

This study focuses on the impacts of the draft on the characteristics of MVS produced CVC blended yarn. The output of a finisher drawn sliver with a linear density of 3.54 ktex was converted into yarns of 18.45 tex (32 s /1 Ne) with the help of two separate delivery speeds: 350 and 410 m/min when possessing all constant spinning parameters. The properties of the yarn such as yarn anomaly, imperfections, tensile behaviour, and hairiness were investigated. The significance of independent variables and their relations with the physico-mechanical characteristics of CVC yarn was examined using two-way ANOVA at a 95% level of confidence.

10

Modelling and optimization of wear parameters of Al 4032 reinforced with coal ash using Taguchi and RSM approach

Gudimetla Avinash, Lingaraju Dumpla, Sambhu Prasad S.

Composites Theory and Practice

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2021

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R. 21, nr 1-2

3--11

EN

The present study aimed to analyze the wear behaviour of composites synthesized by reinforcing Al 4032 with 2, 4, 6 wt.% of coal ash using the stir casting technique. Wear testing was performed on the composites at room temperature in the absence of lubrication using a pin-on-disc tribometer considering the process parameters as wt.% of reinforcement, speed and load. Micro structural characterization using scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX) was performed on the cast composites to ascertain the existence of the reinforcement along with its distribution in the prepared composites. The Taguchi L16 orthogonal array was utilized to design experiments to study the significance of the process parameters on the wear rate. A mathematical model was developed for the wear rate using response surface methodology (RSM). 6 wt.% reinforcement, at the speed of 100 rpm and 10 N load were the obtained optimized parameters for the minimum wear rate. Surface plots as well as contour plots were analyzed to understand the consequence of the process parameters on the wear rate. The analysis of variance (ANOVA) revealed that speed with 76.10 % was the most prominent parameter followed by load and reinforcement with 11.23 and 9.42% respectively.

11

Modeling of methane and air velocity behavior in an auxiliary ventilated coal heading

Daloğlu Gülnaz, Önder Mustafa, Parra Teresa

Archives of Mining Sciences

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2021

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Vol. 66, no. 1

69--84

EN

It is commonly known that the cause of serious accidents in underground coal mining is methane. Thus, computational fluid dynamics (CFD) becomes a useful tool to simulate methane dispersion and to evaluate the performance of the ventilation system in order to prevent mine accidents related to methane. In this study, numerical and experimental studies of the methane concentration and air velocity behaviour were carried out. The experiment was conducted in an auxiliary ventilated coal heading in Turkish Hard Coal Enterprises (TTK), which is the most predominant coal producer in Turkey. The simulations were modeled using Fluent-Ansys v.12. Significant correlations were found when experimental values and modeling results were compared with statistical analysis. The CFD modeling of the methane and air velocity in the headings especially uses in auxiliary ventilation systems of places where it is hard to measure or when the measurements made are inadequate.

12

Optimization of Output Responses during EDM of AZ91 Magnesium Alloy using Grey Relational Analysis and TOPSIS

Tajdeen A., Megalingam A.

Archives of Metallurgy and Materials

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2021

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Vol. 66, iss. 4

1105--1113

EN

Unconventional machining of magnesium alloys through die sinking and Wire Electrical Discharge Machining (WEDM) processes are preferred over conventional machining processes to overcome the rapid loss in strength and affinity that occurs with tool materials at high temperatures. in the present study, AZ91 magnesium alloy is machined in EDM using a prepared alloy tool (copper alloyed with titanium diboride). Based on Taguchi’s L27 orthogonal array, a total of 27 experiments have been conducted by varying the process parameters such as pulse on time (Ton), gap voltage (Vg) and current (Ip) with three different levels. Techniques for Order Preference by Similarity to Ideal Solution (TOPSIS) and Grey Relational Analysis (GRA) have been applied to optimize the response parameters of EDM to obtain maximum Material Removal Rate (MRR) and minimum Tool Wear Rate (TWR) and Surface Roughness (SR). Analysis of variance (ANOVA) is carried out based on F-test at a confidence interval of 95% to confirm the significant influence of individual parameters. From the above two optimization techniques, the obtained optimal values are current 15 A, gap voltage 55 V, pulse on time 30 μs and an error of less than 5% is observed from the confirmation experiments. Scanning Electron Microscope (SEM) images revealed that there is no formation of cracks but micro pits and holes are observed.

13

The measurements of PM2.5 dust concentration by using an integrated optical sensor

Roman Kamil Krzysztof, Borek Kinga, Mazur Kamila, Wardal Witold Jan

Przegląd Elektrotechniczny

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2020

|

R. 96, nr 4

129--132

EN

Dust measurement depends of analog value of voltage read is equal to the PM2.5 dust concentration. The recorded values were analyzed by the ANOVA multivariate analysis. During the statistical analyzes, it was found the relative humidity influence on the PM2.5 dustiness level. The influence of the air temperature on the PM2.5 dust emissions was also found.

PL

Pomiar zapylenia zależy od wysokości odczytanego napięcia na wyjściu analogowym i odpowiada wartości stężenia pyłów PM2.5. Określone podczas pomiarów wartości jako czynniki materiałowe surowca poddano analizie statystycznej wykorzystując metodę wieloczynnikowej analizy wariancji ANOVA. W świetle analiz statystycznych stwierdzono, że istnieje wpływ wilgotności względnej na poziom zapylenia PM2,5. Dodatkowo, zaobserwowano wpływ temperatury powietrza na poziom emisji pyłów PM2,5.

14

Parameters optimization of MAG welding for enhancing the mechanical properties and buckling behaviour of welded steel

Alwan A. H., Mahmood N. Y.

Journal of Achievements in Materials and Manufacturing Engineering

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2020

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Vol. 99, nr 1

5--13

EN

Purpose: The influence of metal active gas welding variables, including current, wire feeding speed and gas flow rate on the ultimate tensile strength and critical buckling load of steel (St.24) and the optimized welding conditions were discussed. Design/methodology/approach: The experimental steps are firstly designing the experiments, secondly conducting the mechanical tests, thirdly analysing the results through Minitab 16 and finally determining the optimum welding parameters. Confirmation tests of the optimized variables were validated. Findings: ANOVA approach manifested that the significant effect of welding variable on the tensile strength was the gas flow rate, while the current was on the critical buckling load. The results are confirmed and given the optimum values. Research limitations/implications: The influence of MAG welding variables (current, wire feeding speed and gas flow rate) on the tensile and buckling strengths of steel will be investigated in order to avoid the failure of many welded assemblies in the structures due to the buckling, in addition to reduce the requirement of long time and high cost to produce such assemblies. Therefore, it is necessary to find a solution to encounter the difficulties in their welding process. Practical implications: The major challenge was how to reduce the time and cost beside gaining the optimum properties through the designed experiments. Originality/value: The results may be helpful to design any welded joints in machine frames, structural steel connections and crane structures at the optimum condition.

15

Analysis and optimization of radiant cooling panel with wave-type embedded pipes

Prasanna Ramprasad, Moorthy Prakash, Krishnan Aravind, Balakrishnan Venkatesh

Engineering Transactions

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2020

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Vol. 68, iss. 1

47--67

EN

In this study, the radiant cooling panel with wave-type pattern pipes is analyzed and optimized through Taguchi’s design of experiments methods and grey relation method for better performance. Radiant cooling panel’s bottom surface temperature and temperature non-uniformity index are considered as the quality objective functions. Control parameters such as pipe length, the spacing between the pipes, radiant panel thickness, pipe bent radius, pipe diameter, insulation layer thickness, pipe material, panel material, insulation material, and mass flow rate of water entering the pipe are included as the control parameters of the optimization study. The performance of radiant cooling panels is analyzed through numerical simulation technique- computation fluid dynamic (CFD) method. The numerical simulation is carried out in the Fluent software, and the CFD code is checked for grid independence and validation. Through single and multi-objective optimization, the best design of the radiant cooling panel is identified, and a confirmation test is also conducted. Finally, an analysis of variance (ANOVA) calculation is made and it is found that the mass flow rate of water entering the pipe is the most influencing parameter on the performance of the radiant cooling panel.

16

Optimization on friction and wear behaviour of Al-Si alloy reinforced with B4C particles by Powder Metallurgy using Taguchi design

Jeya Raj R., Lenin Anselm W. A., Jinnah Sheik Mohamed M., Christopher Ezhil Singh S., John T. D., Rajeev D., Glan Devadhas G., Jaya Christyan K. G., Malkiya Rasalin Prince R., Jeen Robert R. B.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2020

|

Vol. 68, nr 6

1393--1402

EN

This research paper discusses the friction and wear behaviour of Al-12Si alloy reinforced with B4C prepared through Powder Metallurgy (P/M) method by varying the weight percentage of reinforcement (x = 2, 4, 6, 8, and 10) content. The samples were prepared by using die and punch assembly and the lubricant used to eject the sample from the die was molybdenum disulfide. The compaction was done by using a compression testing machine by applying a pressure of 800 MPa. The dry sliding friction and wear behaviour of the sample was conducted on a Pin-on-Disc machine and the experimental values of friction and wear were calibrated. The Taguchi design experiment was done by applying an L25 orthogonal array for 3 factors at 5 levels for the response parameter Coefficient of Friction (CoF) and wear loss. The SEM images show the shape, size and EDX confirm the existence of Al, Si, B4C particles in the composites. Analysis of Variance (ANOVA) for CoF of S/N ratio, shows that the reinforcement having 34.92% influence towards the S/N ratio of CoF, ANOVA for wear loss of S/N ratio shows that the sliding distance having 46.76% influence towards the S/N ratio of wear loss, when compared to that of the other two input parameters. The interaction line plot and the 2Dsurface plot for CoF and wear loss show that the increase in B4C content decreases the wear loss and CoF. The worn surface shows that the B4C addition will increase the wear resistance.

17

Optimization of process parameters of friction stir welded AA5082-AA7075 butt joints using resonance fatigue properties

Kumar G., Kumar R., Kumar R.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2020

|

Vol. 68, nr 1

99--108

EN

In this work, experiments were carried out to quantify the behaviour of friction stir welded (FSW) AA5082-AA7075 butt joints under tensile loading and completely reversed fatigue loading. Different samples were prepared to identify optimum tool rotational and travel speeds to produce FSW AA5082-AA7075 butt joints with the maximum fatigue life. ANOVA was performed, which confirmed that both tool speed nad tool rotation speed affect the tensile strength of the weld. The samples exhibit a considerable difference in their fatigue life and tensile strenght. This difference can be accounted to the presence of welding defects such as surface defects and porosity. S-N curve plotted for the sample shows a significantly high fatigue life at the lower stress ranges. Fracture surfaces were also analysed under scanning electron microscope (SEM). Study of the fracture surface of the sample that failed under fatigue loading showed that the surface was mainly divided in two zones. The first zone was the area of fatigue crack growth where each stress cycle, slowly and gradually, helped in the growth of crack. The second zone was the region of fast fracture where the crack growth resulted in the failure of the joint instantaneously. The fracture surface study of the sample that failed under tensile loading showed that the mode of failure was ductile in nature.

18

The application of selected quality tools in analysing the reasons for discrepancies in wet refractory mortar manufacture

Kieć Monika, Bugdol Marek

Zeszyty Naukowe. Organizacja i Zarządzanie / Politechnika Śląska

|

2019

|

z. 136

221--241

EN

The basic objective of this paper is to present the possibilities of applying selected quality tools in analysing the reasons for discrepancies as exemplified by the process of manufacturing wet refractory mortars. Using various methods and tools, the authors looked for the root causes of a quality rejects occurrence. The following selected methods and tools were used: analysis of variance – ANOVA, the individual moving range (I-MR) chart, SIPOC process mapping, analysis of regression, identification of potential root causes of a problem – 7M, Gauge Repeatability and Reproducibility (GRR). The paper shows how it is possible to search for the causes of quality rejects by means of deliberately selected tools and methods and to successfully decrease the number of discrepancies after introduction of the appropriate corrective actions. The authors indicate how it is possible to analyse the processes of manufacturing wet refractory mortars and what can be done in the situation when a faulty measuring system (returning seriously erroneous results) is the reason for a lack of or lower detectability of wet mortar flaws as it has affected the accuracy of feeding of all components of the recipe, as well as the consistency, moisture content, and hardness/softness of mortar. The collected analysis results allowed the authors to conclude that there were seven probable root causes influencing the hardening of mortar and the loss of its primary functions. This paper could be useful for those wet refractory mortars manufacturers who find it difficult to build their knowledge about product properties based on available publications sources.

19

The experimental determination of cutting forces in a cutting zone during the orthogonal turning of a GRADE 2 titanium alloy tube

Ślusarczyk Łukasz, Franczyk Emilia

Technical Transactions

|

2019

|

Vol. 116, iss. 8

183--194

EN

This article presents the results of laboratory tests involving the measurement of cutting forces during the orthogonal turning of a tube made of GRADE 2 titanium alloy. The nominal diameter of the turned tube was D = 60 mm, and its wall thickness was 2.77 mm. For research purposes, a Kennametal chisel with an insert marked A3G0500M05P04DF and a holder marked A3SAR2520M0425-075-100 was used. An experimental research plan for variable cutting parameters (ƒ, νc) was developed according to the Taguchi method and statistical analysis of the results was performed using an ANOVA. Three series of tests were performed, one for each of the three different values of tube wall thickness (ap = 2.77, 1.77, 0.5 mm). In accordance with the prepared test plan, nine trials were conducted within each series. Cutting forces were measured during each test with the use of a 3-axis Kisler 9257B piezoelectric dynamometer. DynoWare computer software was used for the archiving and analysis of measurement results.

PL

Artykuł prezentuje wyniki badań laboratoryjnych pomiaru sił skrawania podczas toczenia ortogonalnego rury z tytanu GRADE 2. Nominalna średnica toczonej rury wynosiła D = 60 mm, natomiast grubość ścianki 2,77 mm. Do badań wykorzystano przecinak firmy Kennametal o oznaczeniu płytki A3G0500M05P04DF, zamontowanej w oprawce A3SAR2520M0425-075-100. Eksperymentalny plan badań dla zmiennych parametrów skrawania (ƒ, νc) opracowano według metody Taguchi, natomiast statystyczne opracowanie wyników wykonano za pomocą analizy ANOVA. W czasie prac zostały przeprowadzone trzy serie prób trzech różnych wartości grubości ścianki rury (ap = 2,77; 1,77; 0,5 mm). W ramach każdej serii zgodnie z opracowanym planem badań wykonano 9 prób. Pomiar sił skrawania był realizowany w każdej próbie za pomocą 3-osiowego siłomierza piezoelektrycznego Kisler 9257B. Do archiwizacji i analizy wyników pomiarów zastosowano program komputerowy DynoWare.

20

An analysis of fast-changing phenomena in the cutting zone during the turning of a Ti-6AL-4V titanium alloy shaft

Ślusarczyk Łukasz, Franczyk Emilia

Technical Transactions

|

2019

|

Vol. 116, iss. 8

173--182

EN

This paper presents an experimental method of determining the velocity of chip flow on the rake surface of a cutting insert during the longitudinal turning of Ti-6Al-4V titanium alloy. A Seco CNMG120408-M1 833 carbide cutting insert without a protective coating was used for the purposes of research. In order to record phenomena in the cutting zone, a PHANTOM V5.2 high-speed camera was used and placed above the area of machining. The camera recorded the process at a speed of 3000 fps. Placing the camera near the cutting zone allowed recording the process of chip formation and its flow along the rake face of the insert. Trials of longitudinal turning were performed in accordance with the test plan, where ν🇨 and ƒ were the independent variables. In addition, the tests were performed for two different cutting depths. Processing and analysis of the obtained video sequences were performed with the use of CineViewer 663 and Tracker computer applications. Experimental determination of the velocity of chip flow at the rake face of a cutting insert was conducted by analysing the movement of the characteristic point on the outside side of the chip. Analysis of variance for the obtained results was performed using ANOVA and the regression functions were determined.

PL

W artykule przedstawiono eksperymentalny sposób wyznaczania prędkości spływu wióra po powierzchni natarcia płytki skrawającej podczas toczenia wzdłużnego stopu tytanu Ti-6Al-4V. W ramach badań wykorzystano płytkę skrawającą z węglika spiekanego, bez powłoki ochronnej, Seco CNMG120408 M1 833. Do rejestracji zjawisk w strefie skrawania zastosowano kamerę szybkoklatkową PHANTOM V5.2 umieszczoną nad strefą obróbki. Szybkość rejestracji kamery wynosiła 3000 kl/s. Ustawienie kamery w tym miejscu umożliwiało rejestrację procesu powstawania i spływu wióra po powierzchni natarcia płytki. Próby toczenia wzdłużnego realizowano zgodnie z przyjętym planem badań, gdzie zmiennymi niezależnymi były ν🇨 i ƒ. Dodatkowo próby wykonano dla dwóch różnych głębokości skrawania. Obróbkę i analizę otrzymanych sekwencji wideo przeprowadzono w aplikacjach komputerowych CineViewer 663 oraz Tracker. Eksperymentalne wyznaczenia prędkości spływu wióra na powierzchni natarcia płytki skrawającej realizowano przez analizę ruchu punktu charakterystycznego na zewnętrznej stronie wióra. Dla uzyskanych wyników przeprowadzono analizę wariancji ANOVA i wyznaczono funkcje regresji.