International Journal of Materials and Product Technology (28 papers in press)
Theoretical procedure for the stress state assessment of hyper-static crankshafts
by Sergio Baragetti
Abstract: Crankshafts with many rods and crankpins for mechanical and industrial applications can be designed with first-order-approximation theoretical procedures in the literature. Numerical Boundary Element Method (BEM) or Finite Element Method (FEM) procedures can be used, with the latter models having a 3D tetrahedral wire beam of hexahedral finite elements. To the best of the authors knowledge, the literature does not contain accurate evaluations of hyper-static reactions at the restraints of a crankshaft with four crankpins and five supports. The principle of virtual work is implemented to allow calculation of the reactions at the bearings of the shaft and to determine the internal actions (bending, torsion, shear and axial force) for each section of the shaft. The developed procedure does not give better results than a numerical BEM or 3D FEM code, but it is less expensive and less time consuming when implemented in a mathematical commercial code. Furthermore, the procedure gives results that have a better approximation with respect to the theoretical literature models. The theoretical model was validated through comparison with the results of a finite-element linear beam model developed using a commercial FEM code.
Keywords: Four-rod crankshaft; Theoretical model; Machine design; Performance enhancement; Fatigue design.
A method to determine the forming limit for cross-section distortion of rectangular tube in rotary draw bending process
by Ning Guo, Kuanxin Liu, Shunqi Zheng, KeMin Xue, WenTao Huang
Abstract: In the manuscript, the forming limit for cross-section distortion is defined according to the employing area and aviation standard. First, the definition and determination method of forming limits is proposed. And then, the effects of process parameters on forming limit are investigated- based the 3D FE simulation model. It is found that with the increase of height, clearance between mandrel and tube, clearance between core and tube and the strengthen coefficient, the minimum bend radius increases and the bending limit decreases; with the increase of width and strain-hardening exponent, the minimum bending radius decreases and the bending limit increases. Finally, the 3D forming limit diagrams for cross-section distortion are obtained under different process parameters.
Keywords: Forming limit; minimum bending radius; cross-section distortion.
METHODOLOGY FOR DATABASE DEVELOPMENT FOR ELECTRO DISCHARGE BORING OF AEROSPACE MATERIAL
by Sudhanshu Kumar, Harshit K. Dave, Keyur P. Desai
Abstract: In the present investigation, boring of an aerospace material (Inconel 718) is performed on electro discharge machine. Boring operation of predrilled circular cavity is achieved using tool movement on radial path during EDM process. The actuation of tool electrode is guided and controlled in such a way that it moves on a radial path with an angular increment of 5 degree from previous path. Using Taguchi design of experiment and application of multiple regression equations, a database is generated for the selection of suitable combination of process parameters for boring operation in EDM process. The criterion of creating the database for proper selection of parameters is to minimize the overcut while maintaining the surface roughness within the specified range during boring operation. In this methodology, the parameters that have lesser influence on surface roughness are identified and then their levels are suitably chosen for minimum overcut generation. Remaining factors levels are varied in such a way that the surface roughness will remain within the specified range. This type of technological database will be very useful for application in future, as it will provide direct selection of appropriate combination of parameters for boring of Inconel 718 using EDM process.
Keywords: Boring; overcut; surface roughness; Inconel; radial tool movement; electro discharge machining.
Effect of TiO2 enriched fluxes on the bead geometry, grain size and hardness in Submerged Arc welds
by Joydeep Roy, Ram Naresh Rai, Subhashchandra Saha
Abstract: This work is mainly concerned about the influence of titanium dioxide powder addition into flux on the bead geometry, grain size, and hardness in submerged arc weld of low alloy steel plates. Titanium dioxide powders were mixed with the commercial fluxes in a different proportion of 2.5, 5, 7.5, 10 and 12.5%. The welding process parameters were kept constant for different welding conditions. Bead geometry parameters show a significant improvement due to the titanium dioxide addition. 5% of titanium dioxide enrichment was showing the best result for the bead geometry parameters. Nucleation of the acicular ferrite and grain refinement of weld metal (WM) microstructure has been observed with the enrichment of titanium. Average grain size of ferrite and pearlite decreases with the increase of titanium content. Phase analysis of weld metals shows that the ferrite% increased and pearlite% decreased with respect to titanium content. But the increase of titanium content was not showing any clear trend on the hardness profile of weldments.
Keywords: SAW; bead geometry; phase analysis; grain size; hardness.
Application and Anti-bacterial Performance Evaluation of Liquid Glass Coating
by Bingjie Xiao, Ayman Ibrahim, Xiao Huang, Rong Liu
Abstract: Liquid glass (LG) coating, supplied by Liquid Glass Shield Company, is capable of enhancing the wear resistance of surfaces without altering the surface features. Additionally, the coating contains ethanol that acts as an anti-microbial agent. In this study, LG is deposited on nickel substrate to investigate its ability to impede bacterial growth. The coating is applied using a spin coater and followed by a furnace curing process. The coating is then tested for bacterial growth through the deposition of a known type of bacteria onto the cured coating surface. The liquid glass coating has shown enhanced anti-bacterial ability when compared to bare nickel surface. However, the anti-bacterial ability of LG is slightly lower than that of brass alloys.
Keywords: liquid glass coating; anti-bacterial performance; E.coli; colony-forming unit; nickel; brass; benzalkonium chloride; sodium pyrithion.
Experimental and mathematical evaluation of thermal and tensile properties of friction stir welded joint
by Ratnesh Kumar, Bhabani Bora, Somnath Chattopadhyaya, Grzegorz Krolczyk, Sergej Hloch
Abstract: The aim of this experimental work is to develop a mathematical model of friction stir welded joint of aluminum alloy 6061-T6 for correlating the process parameters (rotational speed, welding speed) with output responses (Maximum Process Temperature, Yield Strength, Ultimate Tensile Strength and % Elongation).This developed model provides an empirical relationship between the modeled values and experimental values. Experiments of AA 6061-T6 FSW butt joint were carried out using the Full Factorial design of experiment. Analysis of variance and scatter diagram has been employed to assess the significant effect of the factors and the adequacy of the models developed for the response variables. The optimum values of output responses i.e. TMax, YS, UTS and % E are found as 417.98
Keywords: Friction Stir Welding; Full Factorial Design; ANOVA; Genetic Algorithm.
Experimental Design of a Folded-Structure Energy-Absorption System
by Haim Baruh, Elsayed Elsayed
Abstract: This paper describes the design and analysis of an energy-absorption-system container made of chevron-pattern folded paper for the purpose of encasing supplies to be dropped from moving aircraft without using a parachute. A mathematical model of the energy absorption system is developed. The constitutive properties of the system are ascertained experimentally, and the system is tested by dropping containers with different types of cargo and from different altitudes and aircraft speeds without a parachute.
Test results in a laboratory and actual drop tests from moving aircraft demonstrate that this energy-absorption system manufactured using the paper-folding machine, built at Rutgers University, absorbs the impact energy of the drop and protects the cargo from the collision forces that are encountered when the dropped container impacts the ground and tumbles. It is shown that the design can successfully protect items with different fragilities inside containers dropped from different altitudes up to 30 m with aircraft speeds up to 70 KIAS.
Keywords: folded structures; energy absorption; drop tests; constitutive properties; impact testing.
Multi-objectives optimization of PU foams on acoustic performance by using design of experiment
by Chen Shuming, Jiang Yang
Abstract: The main objective of this study was to obtain an optimal formulation of PU foams with improved acoustic properties by using design of experiment (DOE). With the aim to obtain an efficient acoustic material, the PU foams formulation can be optimized successfully by adjusting the content of various additive components in this experiment. The experiments were conducted with four controllable 3-level factors and two target objectives, and Taguchis orthogonal array L9(34) had been chosen. The various additive components were: water (3.8-4.8 part by weight), tri-ethanolamine (TEA, 2-3 part by weight), HCFC-141b (4-6 part by weight) and A33 (0.9-1.1 part by weight). Sound absorption coefficient and transmission loss were both chosen as target objectives. The best formulation that optimized the acoustic properties of PU foams were determined by analysis of variance (ANOVA). From the results, the most significant factor affecting the experimental design objectives was identified.
Keywords: Optimizaiton; orthogonal array; sound absorption coefficient; transmission loss;.
A comprehensive review of microstructure evolution during friction stir welding of aluminium to copper
by Tanmoy Medhi, Barnik Saha Roy, Subhash Chandra Saha
Abstract: The present review paper focuses on the various researches done in joining of aluminium and copper by friction stir welding (FSW). Being a solid state process, FSW has proven to efficiently join aluminium and copper which is extensively used in power generation, electrical and electronic industry. However, it is a challenge to achieve a good quality welded joint of aluminium and copper due to the difference in properties of both the materials. The present review paper comprehensively reports the study of microstructure and its evolution during the process. Also, an assessment of the formation of different intermetallic compounds (IMCs) during the process and the effect of various process parameters like rotational speed, tool traverse speed, the arrangement of base materials, offset and tool geometry on the IMCs and microstructure evolution is given.
Keywords: Friction stir welding; Aluminium; Copper; Microstructure; Intermetallic compounds.
On the improved mechanical properties of nanoclay reinforced ABS composite for Fused Deposition Modelling
by Vishal Francis, Prashant K. Jain
Abstract: Due to the restrictions imposed by the availability of materials in Fused Deposition Modelling process (FDM), the achieved mechanical properties of FDM parts are limited. This scarceness leads to a critical need for improving the mechanical properties of FDM parts. The incorporation of nanoclay can effectively improve the mechanical properties of polymeric materials used in FDM. The present study investigates the FDM of clay-based polymer nanocomposite and examines the effect of dual extrusion in part fabrication. Multiobjective optimization, grey relation based Taguchi technique was used to determine the optimal processing temperature and clay content. Mechanical characterisation was performed on the nanocomposite developed and hybrid parts fabricated by dual extrusion. Microstructure investigation was carried out to examine the interaction between nanofiller and polymer for the developed filament and to study the fracture surface morphology. Incorporation of nanoclay demonstrated significant improvement in tensile, modulus and compressive strength as 14.5%, 21% and 24% respectively. A substantial increase in modulus and compressive behaviour was observed in hybrid parts. Hybrid parts demonstrated an increase in modulus as 70%, 94.8% and 147.8% for transverse, boundary and longitudinal reinforcement respectively along with an increase in compressive strength. The microstructure examination revealed that nanocomposite parts have fewer voids compared to ABS specimens due to better neck formation between the rasters. The developed material possesses enhanced properties compared to the virgin polymer and can be used effectively as an alternative material for FDM process. Dual extrusion technique can aid to tailor material properties as per the requirements in FDM parts.
Keywords: Fused Deposition Modelling; Dual extrusion; nanoclay; nanocomposite; grey Taguchi method.
Determination of Heat Transfer Coefficients for Large Scale Steel Forgings Quenched in Polymer Solutions
by Jesús Mario Luna-González, Edgar Ivan Saldana-Garza, Rafael David Mercado-Solís, Luis Adolfo Leduc-Lezama, Bradley Wynne
Abstract: The inverse heat conduction method is used to calculate surface heat transfer coefficients (HTCs) as a function of temperature and location during quenching of a complex geometry large steel forging in a static polymer solution. Experimental temperature-time data extracted from the piece were used as input data to calculate the HTC. The geometry was divided into seven different zones (surfaces). An individual HTC, with a high level of experimental confidence, was calculated for each zone by using the inverse heat transfer module of the commercial software DEFORM 2D/3D. These HTCs were then used to predict the through thickness cooling behaviour of the component with a high degree of replication. This method thus appears be useful for further understanding the quenching process on large steel forgings, in general, but could be critical for obtaining accurate cooling behaviour in forgings with non-simple shapes, where one HTC may not be sufficient to describe local cooling behaviour.
Keywords: Inverse HEAT CONDUCTION PROBLEM; heat transfer coefficient; large scale forgings; quenching; polymer quenchant; computational simulation; quenching simulation; cooling curves; meshing; DEFORM 2D/3D.
Investigation into the Effectiveness of Cutting Parameters on Wear Regions of the Flank Wear Curve and Associated Cutting Tool Life Improvement
by Erhan Altan, Alper Uysal, Oguz Caliskan
Abstract: In machining operations, less tool wear and superior tool life are desired. Therefore, the effects of cutting parameters on tool life should be known and optimal cutting parameters should be chosen to reduce tool wear. In this study, the effectiveness values of cutting parameters on each wear region in the cutting tool flank wear curve were investigated to improve cutting tool service life. For this reason, some statistical methods were employed to determine them and the results were verified by experimental studies. The experiments were performed by turning of AISI 1040 carbon steel with uncoated WC (Tungsten Carbide) cutting tools at different cutting speeds, feeds and depths of cut. In the initial tool wear and the rapid tool wear regions, the most effective parameter was found as the feed and the tool wear increased with increase of the feed. In the steady-state tool wear region, the effectiveness values of the cutting speed and the feed were very close to each other, but the cutting speed was determined a little more effective. After the most effective cutting parameters on all tool wear regions were determined, validation experiments were conducted by considering these results to increase tool life during turning AISI 1040 carbon steel and AISI 4140 alloy steel. As a result, significant improvements on the tool life were obtained by properly choosing the cutting parameters for each cutting tool wear region.
Keywords: Tool life; Flank wear; Wear regions; Turning; Taguchi method.
Parametric optimisation in Nd-YAG laser cutting of Thin Ti-6Al-4V super alloy sheet using evolutionary algorithms
by A. Tamilarasan
Abstract: In this paper, genetic and simulated annealing algorithm approaches are proposed for the selection of the optimal values in efficient Nd-YAG laser cutting of thin Ti-6Al-4V super alloy sheet. The pulse width, pulse energy, cutting speed, and gas pressure are considered as process parameters. Response surface methodology based box-behnken design is adopted to conduct the experiments to measure the proposed performance characteristics such as kerf deviation (KD) and metal removal rate (MRR). Quadratic regression models are developed to predict the responses using response surface methodology. Analysis of variance tests have been carried out to check the adequacy of the developed regression models. Based on the developed mathematical models, the interaction effects of the process parameters on KD and MRR are investigated. Minimising KD and maximising the MRR are considered as objectives functions. The optimal laser cutting conditions are obtained to minimise the KD and maximise the MRR in considering single and multi objective optimisation methods. Validation tests with optimal levels of process parameters were performed to illustrate the effectiveness of GA and SA algorithms. It is believed that the used algorithms provides a robust way of looking the optimum process parameters for a selected laser cutting system.
Keywords: Genetic algorithm; kerf deviation; metal removal rate; Nd:YAG laser; optimization; simulated annealing; titanium alloy.
THEORETICAL AND EXPERIMENTAL INVESTIGATION FOR MICRO-CHANNEL FABRICATION USING LOW POWER CO2 LASER
by Arif Varsi, Abdul Hafiz Shaikh
Abstract: CO2 laser being a localized non-contact type machining process depends on the thermal and mechanical properties of a material to a great extent. The scope of this research is to study the effect of process parameters on channel profile of polymethylmethacrylate (PMMA) by CO2 laser (0-25 W). The parameters selected are beam power and scanning speed, keeping assist gas pressure constant. Using the principle of energy balance and assuming complete evaporation of molten material, an analytical model for the depth of cut is developed by considering Gaussian beam energy distribution in three-dimensional coordinate systems. Experimental results obtained at 5 mm thick plate by varying process parameters were compared with the analytical data showing good convergence with a variation of 1.83 %. An attempt is made to analyze the variation of channel geometry as a function of process parameters analytically. The present model was developed with consideration of x, y and z coordinates associated with laser machining process and was validated by experimentation and 2D model available in the literature. It was observed that the proposed model shows good convergence with the experimental values. Hence, the proposed model is found to be suitable for prediction of micro-channel depth with precision.
Keywords: Gaussian beam; PMMA; depth profile; channel geometry.
On the Reduction of Stress Concentration Factor in an infinite panel using different radial functionally graded materials
by Vikas Goyat, Suresh Verma, R.K. Garg
Abstract: This work deals with a parametric study of the stress concentration factor in different functionally graded material panels having a central circular hole subjected to a uniaxial tensile, biaxial tensile and shear load. The extended finite element method along with isoparametric graded finite element material properties modelling scheme is used to evaluate the stress concentration factor. Three candidate material gradation models are tested in this parametric study and various metal ceramic functionally graded materials are also tested for stress concentration. The stress concentration factor evaluated numerically for a wide range of Youngs modulus ratio and power law index are presented. It has been concluded that the low stress concentration factor can be achieved by choosing the proper material gradation model and their power law index for a fixed value of Youngs modulus ratio.
Keywords: Stress Concentration Factor; Power Law FGM; Sigmoid FGM; Extended Finite Element Method; Hole.
Wear Characteristics of a Combustion Liner for Power Generation Gas Turbine
by Ahmad Afiq Pauzi, Mariyam Jameelah Ghazali, Salmi Mohd Yunus, Wan Fathul Hakim W. Zamri, Shuib Husin
Abstract: Wear is the main degradation of combustor components for power generation gas turbine. The occurrence of wear damage was observed on a combustion liner, which is one of the vital components in the gas turbine. The combustion liner is made from Hastelloy X (a nickel based superalloy material). The worn surface generally occurred at the mating surfaces of combustion liner. In the gas turbine, the combustion liner is mating to four different components, which are fuel nozzle, cross fire tube, flow sleeve and transition piece. The purpose of this study is to determine and characterise the dominant wear mechanisms at three different mating surfaces (connected to a stainless steel, Nimonic 263 and carbon steel) after being exposed to 8,000 running hours at high temperature and vibration. The worn surfaces were analysed and the wear mechanism was discussed.
Keywords: wear; combustion liner; power generation gas turbine.
Multi-response optimisation for MRR and Ra in WEDM process of Nimonic-263 super alloy
by M. Sreenivasa Rao, N. Venkaiah
Abstract: Nimonic-263 is a nickel-based super alloy with exciting applications. It can retain high hardness and low thermal conductivity even at elevated temperatures. Due to these reasons machining of these alloys using conventional machining is very difficult and therefore wire electrical discharge machining (WEDM) has been selected to machine the material. To get the optimal performance level, the process parameters have to be set carefully. Furthermore, multi-objective optimisation of WEDM process is too difficult as it involves several process parameters. Although there are several multi-response optimisation techniques, industry is faced with a problem of choosing the best technique. The objective of the present work is, therefore, to apply different multi-response optimisation techniques, which are easy to implement and involve less computational effort with a view to recommend best technique. Response surface methodology (RSM) has been used for experimental design. A comparative analysis among the optimisation techniques is carried out. It has been observed that technique for order preferences by similarity to an ideal solution (TOPSIS) is found to be the best among different multi-response optimisations techniques chosen. The total predicted SN ratio values of TOPSIS are 30% more than that of the other methods.
Keywords: wire electrical discharge machining; WEDM; response surface methodology; RSM; multi-response; Nimonic-263; optimisation.
Powder-materials impact on nanoparticle-reinforced Ti-6Al-4V matrix composites produced via inductive hot pressing
by Isabel Montealegre-Meléndez, Erich Neubauer, Cristina Arévalo, Eva Maria Perez-Soriano, Michael Kitzmantel
Abstract: This paper addresses the optimal manufacture of titanium alloy composites via inductive hot pressing, and studies the influence of nanosized reinforcement and matrix powders on the final properties of the titanium-based composites. Before hot consolidation, two types of Ti-6Al-4V powders were mixed with various percentages of nano-diamonds. After inductive hot pressing at 900°C and 950°C, characterisation of the specimens took place, which revealed significant differences in the final properties of the composites produced. Further to the well-known effect of how oxygen content in the initial powder considerably affects the properties of the specimens, the influence of the nano-diamonds in the microstructure is also evaluated.
Keywords: titanium alloys; nano-diamonds; metal matrix composites; inductive hot pressing; iHP.
On rapid prototyping of assembly systems - a modular approach
by Zhiqin Qian, Tan Zhang, Mengya Cai, Wenjun Lin, Wenjun Zhang
Abstract: This paper proposes a new product and manufacturing technology for rapid prototyping of product systems (RPPSs). It is noted that a system in this paper is defined as a physical assembly that can be decomposed into components. The rapid prototyping is achieved by a novel modular concept, that is, the base materials to build a component as well as an assembly is highly modularised (the interface between any two modules are identical) and building a system is simply by assembling the modules. The rapid prototyping in this paper differs significantly from the rapid prototyping in literature in that the latter builds a system layer by layer and further primarily builds a component instead of assembly (building of an assembly is actually very limited with the latter, though possible). This paper explains the RPPS approach and presents a feasibility study on the RPPS technology. It has been shown that the RPPS technology is promising.
Keywords: rapid prototyping of assembly; evolutionary algorithm; modular plastic module; MPM.
Application of genetic algorithm in optimisation of cutting force of Al/SiCp metal matrix composite in end milling process
by M.S. Aezhisai Vallavi, N. Mohan Das Gandhi, C. Velmurugan
Abstract: This paper investigates the cutting force of LM6/SiCp using end milling process. Mathematical models have been developed to predict the cutting force in terms of spindle speed, axial depth of cut and weight percentage of SiCp. Response surface methodology has been employed to create the mathematical model. The experiments have been conducted on LM6/SiCp by carbide insert and cutting forces have been measured using a milling tool dynamometer. The direct and interaction effects are studied with the influence of machining parameters. Analysis of variance (ANOVA) has been used to check the adequacy of the model. Optimum combination can be attained for the best result.
Keywords: cutting force; end milling; metal matrix composite; MMC; response surface methodology; RSM; optimisation.
Experimental modelling and genetic algorithm-based optimisation of friction stir welding process parameters for joining of dissimilar AA5083-O and AA6063-T6 aluminium alloys
by Saurabh Kumar Gupta, K.N. Pandey, Rajneesh Kumar
Abstract: Friction stir welding (FSW) is a solid state joining process and one of the most promising technique for defect free joining of aluminium alloys. In this paper, second order regression modelling and genetic algorithm-based optimisation of FSW process parameters is presented for joining of dissimilar AA5083-O and AA6063-T6 aluminium alloys. For developing the regression model, experiments were performed as per L27 orthogonal array and models were developed with the help of MINITAB software. For genetic algorithm-based process parameter optimisation, regression models were considered as objective functions. The regression models have been found satisfactory for predicting the responses at 99% confidence level. The derived set of optimal process parameters were found as tool rotational speed of 900 rpm, welding speed of 60 mm/min, shoulder diameter of 18 mm and pin diameter of 5 mm for maximum tensile strength and minimum grain size.
Keywords: friction stir welding; FSW; aluminium alloys; genetic algorithm; optimisation; tensile strength; grain size; analysis of variance; regression model.
An experimental study of investigating the relationships between structures and properties of al alloys included with high Mg and high Ti
by Halil Ibrahim Kurt, Ibrahim H. Guzelbey, Serdar Salman
Abstract: In this study, the influences of high magnesium (Mg) and high titanium (Ti) additions on aluminium (Al) alloys were investigated to peruse the relationship between the structure and properties of the new alloys. Microstructural analyses were performed using X-ray diffraction (XRD), the polarised optical microscope, and scanning electron microscope (SEM) equipped with energy dispersive spectrometry (EDS). In the microstructure of the alloys, the β-phase (Al3M2) α-solid solution, Ti2Mg3Al18 and TiAl3 particles were revealed. Results showed that the average grain size of Al-Mg-Ti alloys was found to be different in each composition, and the smallest grain size was obtained at Al-12Mg-3Ti alloy as 88 μm. The highest tensile strength (170 MPa) was attained with additions of 8 wt.% Mg and 1 wt.% Ti, but the highest hardness value (125 HBN) was obtained with additions of 14 wt.% Mg and 3 wt.% Ti. It was noted that the smallest average grain size did not behave in accordance with the highest mechanical properties. For the work, the optimal ratios of magnesium and titanium entrained into Al alloys were 8 wt.%, and 1 wt.%, respectively.
Keywords: Ti and Mg additions; Al-Mg-Ti alloys; microstructure; mechanical and physical properties; casting.
Biomimetic application of non-smooth surface characteristic in anti-sticking drill stem
by Xiaofeng Yang, Re Xia, Hongwei Zhou, Lu Guo, Lijun Zhang
Abstract: It is one of the common phenomenon that the drill stem could be easily stuck in soft stratum, which consequently affects the drilling efficiency seriously. A biomimetic method to relieve the sticking problem of the drill stem is presented and studied. The anti-sticky mechanism of the earthworm for its amazing burrowing in soft soil is investigated and probed further, figuring out the fact that the corrugated surface structure of earthworm could reduce the friction assistance and soil adhesion. Inspired by earthworm, biomimetic drill stem with corrugated surface is designed and applied in soft stratum drilling. The results show that the biomimetic drill stem could effectively avoid being stuck in soft stratum, and the torque and thrust of the biomimetic drill stem show a considerable decrease. The mechanism of its good anti-sticking ability is addressed, and the effects of wavelength on both torque and thrust are investigated for experimental and industrial optimisation.
Keywords: non-smooth surface; earthworm; anti-sticking; friction; biomimetic drill stem.
Special Issue on: Advances in Measurement Science and Technology
Non-contact roundness measurement with air gauges: simulation studies
by Radomir Majchrowski
Abstract: The article presents the results of simulation-based analysis of non-contact roundness measurement of inner cylindrical surfaces. The method is based on the reference measurement with air gauges. The simulation tests were conducted to evaluate the influence of certain parameters on the final measurement results, including the harmonic analysis (up to 15th harmonics). The investigations were aimed to the assessment of influence of particular measurement errors, like the error of the measuring slot, or the non-orthodox position of the measuring head, on the final result of the roundness measurement. These studies results are useful not only in this particular application, but generally in process of design of the non-contact roundness measurement instrument that using air gauges.
Keywords: air gauge; roundness; simulation studies; matlab.
Investigations of Performance Parameters in NFMQL Assisted Turning of Titanium Alloy Using TOPSIS and Particle Swarm Optimization Method
by Munish Gupta, P.K. Sood, Gurraj Singh, Vishal S. Sharma
Abstract: This paper deals with the multi-response optimization of process parameters in nano-fluid based minimum quantity lubrication (NFMQL) assisted turning of titanium (grade-2) alloy. The multi-response optimization methods included are multi-criteria decision making tool i.e., TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) approach and particle swarm optimization (PSO) method. The turning experiments were performed by varying cutting speed (Vc, 200 mm/min 300 mm/min), feed rate (f, 0.10 mm/rev 0.20 mm/rev), approach angle (ϕ, 60
Keywords: ANOVA; Machining; Optimization; PSO; Titanium alloy; TOPSIS.
AIR GAUGE BACK-PRESSURE UNCERTAINTY ESTIMATION FOR THE ADVANCED TEST RIG
by Czeslaw Jermak, Miroslaw Rucki, Michal Jakubowicz
Abstract: In the paper, the uncertainty estimation of the back-pressure measurement in the advanced experimental rig equipped with the electronic devices, pressure transducers, precise step motors is discussed. The proposed apparatus was used in case of some accurate and dedicated applications that required experimental examination of the selected air gauges to confirm their capability. The advanced experimental rig for the air gauges properties assessment is a system consisting of many elements, each of them adding some uncertainty to the final measurement result. The main sources of uncertainty are identified as following: operator, environment, mechanical unit, electronic unit, pneumatic unit, data processing. Assessment of the back-pressure uncertainty was performed using the method A. The series of repetitions revealed that the uncertainty of the back-pressure indication depends on characteristics (measuring range and sensitivity) of the actually examined air gauge. Additional attention was paid to the flow instability in the measuring chamber that cause the instability of the back-pressure measurement results
Keywords: air gauge; uncertainty; back-pressure; air flow; calibration.
Barkhausen noise signal analysis of heat treated samples at various magnetizing frequencies
by Ashish Srivastava, Harikishor Kumar, Mohd.Zaheer Khan Yusufzai, Meghanshu Vashista
Abstract: Signal processing of magnetic Barkhausen noise was performed to reveal the useful information content of the signal which would otherwise difficult due to stochastic nature of the signal. Magnetic Barkhausen noise signal was measured from different heat treated steel samples which were further processed to investigate the effect of heat treatment on Barkhausen noise signal. The dependence of Barkhausen signal upon magnetizing frequency was also discussed in terms of rms value of Barkhausen noise envelope. Variation in the rms value of the Barkahusen noise profile with magnetizing frequency and mechanical properties was explained using micromagnetic theory. The present study shows that Magnetic Barkhausen noise signal depends upon mechanical properties as well as on magnetizing frequency which needs to be optimized in order to use magnetic Barkhausen noise as a characterization tool.
Keywords: Magnetic Barkhausen noise; Heat treatment; Domain wall; Magnetising frequency; Root mean square; Eddy current; Signal processing; Microhardness; Magnetization;Characterization.
Special Issue on: Recent Trends in Design of Nanocomposites Experimental and Theoretical Approaches
Analysis for electromagnetic performance of PM motor with different metal Nano-material bars
by Likun Wang
Abstract: With the appearance of high-performance permanent magnet (PM) materials as well as the development of computer technology and Nanotechnology and electricity machine theory, scholars have done a lot of research on the self-starting permanent magnet synchronous motor and have made many achievements. Although the starting permanent magnet synchronous motor has many advantages compared with the induction motor, there are also many problems. Since the self-starting motor needs to realize the self-starting and maintaining the synchronous speed operation, its rotor structure design is more complex. The rotor requires the starting winding and the magnets coexist, so there is "space competition", especially the small motors with high power density. Nowadays, Nano-materials are applied on a motor to improve its electromagnetic performance. In this paper, the electromagnetic performance of a PM motor with different metal Nano-material bars is researched by finite element analysis (FEA). In this paper, the electromagnetic performance of a PM motor is researched when the rotor bars are with different sizes metal Nano-palladium by FEA. The magnetic field distribution, the dynamic speed and torque variation, and the eddy current losses are analyzed respectively.
Keywords: permanent magnet materials; Nano-material; performance; synchronous motor.