MECHANICS OF SOLID BODIES
|H. Kaya, M. Uçar, A. Cengiz, R. Samur, D. Özyürek, A. Çalışkan.||Novel molding technique for ECAP process and effects on hardness of AA7075 (-)|
|Saleh Yazdani, G. H. Rahimi.||Failure analysis of FML plates with cutouts: Experimental and finite element approaches (-)|
|M. Timur, H. Kuşçu.||Heat transfer of brake pad used in the autos after friction and examination of thermal tension analysis (-)|
MECHANICS OF FLUIDS AND GASES
|B. Peters, A. Džiugys.||Evaluation of heat transfer on a backward acting grate (-)|
|M. R. Rzasa.||Analysis of joining and division of gas bubbles based on measurements of their motion trajectories (-)|
|A.Z. Dellil.||Numerical simulation of a spiral wall (-)|
|A. Mokhtardidouche, A. Benarous, L. Loukarfi, H. Naji.||Numerical prediction of NOx emissions in a full-scale furnace (-)|
|N. Dalir, S. S. Nourazar.||Solution of the boundary layer flow of various nanofluids over a moving semi-infinite plate using HPM (-)|
DYNAMICS OF MECHANICAL SYSTEMS
|I. Mihai, F. Andronic.||Behavior of a semi-active suspension system versus a passive suspension system on an uneven road surface (-)|
DESIGN AND OPTIMIZATION OF MECHANICAL SYSTEMS
|A. Bargelis, D. Čikotienė, Z. Ramonas.||Impact of human factors and errors for product quality and reliability in the integrated approach of product and process design, maintenance and production (-)|
|I. Senkuvienė, K. Jankauskas, H. Kvietkauskas.||Using manufacturing measurement visualization to improve performance (-)|
|D. Szpica, J. Piwnik, M. Sidorowicz.||The motion storage characteristics as the indicator of stability of internal combustion engine - receiver cooperation (-)|
|D. Bručas, L. Šiaudinytė, M. Rybokas, K. Grattan.||Theoretical aspects of the calibration of geodetic angle measurement instrumentation (-)|
NOVEL MOLDING TECHNIQUE FOR ECAP PROCESS AND EFFECTS ON HARDNESS OF AA7075
Kocaeli University, Borusan Campus, Vocational School of Asim Kocabiyik, Department of Machine and Metal Technology, 41380, Hereke, Kocaeli, Turkey, E-mail: email@example.com, firstname.lastname@example.org
M. Uçar, A. Cengiz, A. Çalışkan
Kocaeli University, Umuttepe Campus, Faculty of Technical Education, Department of Machine Education, 41800, Umuttepe, Kocaeli, Turkey, E-mail: email@example.com, firstname.lastname@example.org, email@example.com
Marmara University, Goztepe Campus, Faculty of Technical Education, Department of Metal Education, 34100, Goztepe, İstanbul, Turkey, E-mail: firstname.lastname@example.org
Karabuk University, Baliklar Kayasi Campus, Technology Faculty, Department of Manufacturing Engineering, 78100, Karabuk, Turkey, E-mail: email@example.com
In this study, a novel Equal channel angular pressing (ECAP) diewhich named “Hexa die”,designed and manufactured in orderto reduce process duration and eliminate manual sample rotation problems. For this reason, the surfaces of die was machined to get the cylindrical channels be able to extract out of ECAP samples. These channels provide 100% accuracy for angular routes for cylindrical samples. Experiments are carried out with the same sample materials (AA7075) at a constant temperature (210°C) and “C” rotation. In the study, process time scenarios for traditional and novel Hexa die techniques have been compared in a theoretical time table. It has been shown that Hexa die has crucial time advantages in order to eliminating the old die process steps such as cooling and reheating time, disassembly and re-assembly of the dies, manually rotation of samples and many of others. And finally ECAP’ed samples hardness have been measured.
Keywords: molding, ECAP, deformation, Hexa die, aluminum, hardness.
FAILURE ANALYSIS OF FML PLATES WITH CUTOUTS: EXPERIMENTAL AND FINITE ELEMENT APPROACHES
Mechanical Engineering Department, Tarbiat Modares University, Tehran, Iran, E-mail: firstname.lastname@example.org
G. H. Rahimi
Mechanical Engineering Department, Tarbiat Modares University, Tehran, Iran, E-mail: email@example.com
In this paper, the experimental and numerical failure analysis of Fiber Metal Laminates (FML) with different types of cutouts, were investigated. Fiber metal laminates are types of materials which are consist of combination of metal sheets, especially aluminum ones, with fiber reinforced epoxy layers. At first, specimens were manufactured and elliptical and circular cutouts were created in them. Then subjected to in-plane tensional loading to carry out the behaviors, also, finite element analysis was carried out with ABAQUS commercial software. RIKS method was used in this analysis. Finally, experimental and finite element results were compared with results of elastic compensation method.
Keywords: Failure analysis, Large deflection, Finite element analysis, FML plate.
HEAT TRANSFER OF BRAKE PAD USED IN THE AUTOS AFTER FRICTION AND EXAMINATION OF THERMAL TENSION ANALYSIS
Kırklareli University, Voc. Sch. of Tech. Sciences, 39100 Kırklareli, Turkey, E-mail: firstname.lastname@example.org
Trakya University, Faculty of Engineering and Architecture, 22000 Edirne, Turkey, E-mail: email@example.com
As a result of the friction of brake pads which is one of the factors affecting automobile performances with brake disc, heat energy comes into being. This heat energy causes brake pads to expose to excessive temperature. For this reason, the braking acts of the pads decreases in time and some problems (decrease in the performance of brakes, malfunction, quick pad wear and sound) occur.
In order to eliminate these negative effects emerging on the brake pads, a range of tests were made on pads. To analyze the temperature states of the pads, Solid Works Simulation Solutions module was used. In this program, four different pad materials continually underwent braking act during 300 s process. In terms of revealing the situation of the pads occurring due to wear, two different thicknesses of the same pad were also taken into consideration in the analyses.
Keywords: heat transfer, thermal tension analysis, wears.
EVALUATION OF HEAT TRANSFER ON A BACKWARD ACTING GRATE
Université du Luxembourg, Campus Kirchberg, 6, rue Coudenhove-Kalergi, L-1359 Luxembourg, Luxembourg, E-mail: firstname.lastname@example.org
Lithuanian Energy Institute Breslaujos g. 3, LT-44403 Kaunas, Lithuania, E-mail: email@example.com
Within this contribution the effect of the kinetics of bar motion on the heat-up characteristics of a packed bed, consisting of biomass or municipal waste, on a backward acting grate is investigated. Transfer of heat within a packed bed of moving particles determines to a large extent the individual temperatures of particles, and therefore, any reaction process attached to the particles e.g. packed bed. Thus, a deeper knowledge of heat transfer in a packed bed allows for a better assessment of the reaction progress. Both motion and heat-up of particles on a backward acting grate are predicted by the Discrete Particle Method (DPM). Contrary to continuum mechanic approaches, a packed bed consists of a finite number of individual particles. Motion of particles is predicted by the Discrete Element Method (DEM), whereas the particles' temperatures are determined by the solution of the conservation equation for energy. Particles are heated by a radiative flux on the surface of the packed bed and exchange heat by conduction and radiation with particles in their proximity. Additional heat transfer to the surrounding gas phase by convection is also taken into account.
Keywords: Waste management technologies, Discrete Particle Method, Discrete Element Method, heat-up, backward acting grate.
ANALYSIS OF JOINING AND DIVISION OF GAS BUBBLES BASED ON MEASUREMENTS OF THEIR MOTION TRAJECTORIES
M. R. Rzasa
Technical University of Opole, Mikolajczyka 5, 45-271 Opole, Poland, E-mail: firstname.lastname@example.org
The paper presents considerations on motion of a group of air bubbles. Special attention has been paid to interactions between them. The author presents the test stand structure and the idea of image tomograph used for measurements of bubble motion trajectories. The results of measurements have been presented in a three-dimensional space, and next characteristic behaviours of the moving bubbles were analyzed. Some basic mechanisms of the gas bubble division have been classified.
Keywords: bubble interaction, two-phase flow measurement, imaging tomography.
NUMERICAL SIMULATION OF A SPIRAL WALL
A. Z. Dellil
Institut de Maintenance et de Sécurité Industrielle, IMSI, Université dOran, L.A.H.N., USTO, Oran, Algeria, E-mail: email@example.com
This work presents a study of the thermal characteristics of a turbulent flow of a forced convection along various geometrical configurations: Smooth wall, wall corrugated in spiral, corrugated wall. The effects of pitch/diameter ratio and rib height to diameter ratio made it possible to develop this impact of this geometrical form (sometimes corrugated, sometimes spiral) in the intensification of the heat transfer. The physical process of increase in the heat transfer comes owing to the fact that the spiral shape of the tube contributes to break the formed boundary layer and to allow the continual replacement of the fluid meadows of the solid wall. The numerical results obtained prove that this corrugated form or into spiral intensifies the heat transfer thanks to model SST for Reynolds numbers varying from 5000 to 55000,Indeed when the pitch and the depth of the rib increases from P/dh = 0.18, e/dh = 0.02 to P/dh = 0.27, e/dh = 0.06. The ratio of the numbers of Nusselt increases with the rise in the step and the depth of the notch. Several explanations can be advanced, among these last, the spirals are the cause of the presence of the viscous effects, which slow down the flow in the notch of the spiral (broken boundary layer). The low depth of the notch, going from 0.02 up to 0.04 does not allow a significant thermal intensification, on the other hand for the strong values of the notch (0.05 to 0.06) the presence of turbulence supports good Nusselt. We notes that this last increases with the amplitude of the undulation up to the value of 0.05H. Beyond the value of the amplitude, the number of Nusselt tends towards the constant value.
Keywords: corrugated wall / turbulence model / SST model / thermal transfer.
NUMERICAL PREDICTION OF NOX EMISSIONS IN A FULL-SCALE FURNACE
Hassiba Benbouali University, B.O. 151, Chlef, 02000, Algeria, E-mail: firstname.lastname@example.org
Hassiba Benbouali University, B.O. 151, Chlef, 02000, Algeria, E-mail: email@example.com
Hassiba Benbouali University, B.O. 151, Chlef, 02000, Algeria, E-mail: firstname.lastname@example.org
Artois University & University of Lille, Northern France, Laboratoire Génie Civil et géo-Environnement (EA 4515), Technoparc Futura, F-62400 Béthune, France, E-mail: email@example.com
The present paper deals with a numerical prediction of the thermal level and emission rate of nitrogen oxides within an industrial furnace. Favre averaged forms of the governing equations accounting for radiative heat losses are solved via a finite volume formulation. Turbulent fluxes are closed using a k - e model for which a limited Pope correction is performed. The relaxation model of Magnussen is used to describe the two-step chemistry/turbulence interaction for the non-premixed flame. The effect of the swirl number has been also investigated. The predicted static temperature as well as NO emission rate at the furnace exit show good agreement with in-situ measurements. In addition, the numerical computation shows that the depression is about 28% for the rate of NO, which it is obtained by adopting a moderate swirl at the primary-air entrance.
Keywords:Oxides of nitrogen (NOx), Emission, Turbulent combustion, CFD simulation, Industrial furnace.
SOLUTION OF THE BOUNDARY LAYER FLOW OF VARIOUS NANOFLUIDS OVER A MOVING SEMI-INFINITE PLATE USING HPM
Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran, E-mail: firstname.lastname@example.org
Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran, E-mail: email@example.com
Two-dimensional steady boundary layer flow of nanofluids over a moving impermeable semi-infinite horizontal plate is studied. The plate moves with constant velocity. Similarity transformation is used to transform governing equations to a nonlinear ODE, which is then solved using the semi-analytical homotopy perturbation method (HPM) for various types of nanoparticles: Cu, Al2O3, TiO2, CuO, Ag and SiO2 in water based fluid. The effect of nanoparticle volume fraction and nanoparticle type on flow characteristics is studied and compared with numerical solution. HPM results agree within 2% error with numerical solution. Analyses show that skin friction coefficient increases with nanoparticle volume fraction increase.
Keywords: HPM, boundary layer, nanofluids, moving plate.
BEHAVIOR OF A SEMI-ACTIVE SUSPENSION SYSTEM VERSUS A PASSIVE SUSPENSION SYSTEM ON AN UNEVEN ROAD SURFACE
I. Mihai, F. Andronic
Stefan cel Mare University, Universitatii 13, 720229 Suceava, Romania, E-mail: firstname.lastname@example.org
The present paper intends to study the behavior of semi-active suspension systems in comparison with passive suspension systems when subjected to oscillation sources caused by the rolling surface. For this, it was necessary to establish the equations specific to the passive and semi-active suspension systems. For each case, the simulation schemes were developed using Matlab Simulink. For the simulation, the quarter car model was chosen. In order to verify the correctness of the model, the State Space and Transfer function models were also used. As the passive dampers have a linear dampening characteristic, we studied the semi-active systems that use magneto-rheological dampers with adjustable characteristics. In the simulation diagram we used a PID controller – proportional integrative derivative. Using two types of stimulus signals we analyzed the behavior of the semi-active suspension system with different dampening coefficients. By simulation, response signals for damper/spring displacement and damper/spring velocity were obtained. The analysis of the obtained results shows the advantages of semi-active systems in comparison with passive systems and the limitations of such systems compared to active systems.
Keywords: semi-active suspension, magneto-rheological damper, PID controller, quarter car model.
APPLICATION OF NI-TI SHAPE MEMORY ALLOY ACTUATORS IN A WALKING MICRO-ROBOT
Gheorghe Asachi Technical
University of Iasi, B-dul D. Mangeron 61-63, 700050 Iasi, Romania,
Gheorghe Asachi Technical
University of Iasi, B-dul D. Mangeron 61-63, 700050 Iasi, Romania,
As walking robots are requested to perform tasks in rough terrain, the development of actuators capable to flexibly adapt to the unstructured environment becomes more and more necessary. The conventional mechanisms with stiff joints make the robots more complex, heavy, large and expensive. Shape Memory Alloys are a category of artificial muscles which can be used as actuators for a walking robot. Even if they can exhibit large changes in shape when heated and cooled, only one part of their deformation can be used, if we want to maximize the actuator life. This is why smart mechanisms that can convert the small strain of the wire into large motion are necessary. In this paper, an example of using Shape Memory Alloys as actuators for a hexapod walking micro-robot is presented. A leg mechanism that can convert the small strain of these actuators in large motion is also discussed.
Keywords: flexible actuator, shape memory alloy, walking micro-robot, design.
STUDY ON TEMPERATURE INFLUENCE FACTORS AND ELECTROMAGNETIC HEAT COUPLING OF IN-WHEEL MOTOR FOR MICRO-ELECTRIC VEHICLE
Q. P. Chen
School of Mechatronics Engineering,
East China Jiaotong University, 330013, Nanchang, China,
In order to meet the development requirements of micro-electric vehicle in efficiency, reliability and safety, thermal loss mechanism and temperature influence factors of in-wheel motor are study. The finite element method is used to simulate and analyze internal complex thermal loss and temperature field. The mathematical model of thermal loss and temperature field was established. The united simulation model of in-wheel motor was established by Ansoft Maxwell and Ansys Workbench software, transient state temperature were simulated and analyzed. The influences of load and revolving speed on temperature rise were also studied. The conformity of the test results with the final simulation results indicates that this method can be used to provide a theoretical basis to make further optimal design of the new driving in-wheel motor.
Keywords: finite element method,electromagnetic heat coupling, temperature influence factors,in-wheel motor.
MODELLING AND ANALYSIS OF SYSTEMS WITH CYLINDRICAL PIEZOELECTRIC TRANSDUCERS
A. Buchacz, M. Płaczek, A. Wróbel
Institute of Engineering Processes Automation and Integrated Manufacturing Systems, Silesian University of Technology, Konarskiego 18A, 44-100 Gliwice, Poland, E-mail: email@example.com, firstname.lastname@example.org, email@example.com
Paper presents a proposal of mathematical algorithm used in order to modelling and testing of vibrating mechatronic systems. A shaft is the mechanical subsystem of the considered system. A ring piezoelectric transducer is bonded on the shaft’s surface. Knowledge of the dynamic characteristics of the designed systems is essential for the proper operation and should be taken into consideration during the design phase as well as verified during operation of the system. This is why authors decided to present a method that can be very useful for analysis of such kind of systems. In order to calculate the characteristic of mechatronic system a mechanical subsystem was analysed in the first step. The dynamic flexibility of mechanical subsystem was calculated using the exact and approximate methods. It is impossible to use the exact method in order to analyse mechatronic systems this is why the approximate Galerkin method was used to analyse the system with piezoelectric actuator. An exactness of the approximate method was verified. In the presented work a torsional vibrating mechatronic system with piezoelectric transducer used as the vibration actuator is presented. The considered piezoelectric actuator is the sectional, cylindrical transducer supplied by the external harmonic electric voltage. Obtained results – characteristics of mechanical subsystem and mechatronic system are juxtaposed on charts.
Keywords: modelling, analysis, vibrating mechatronic systems, piezoelectric transducer.
IMPACT OF HUMAN FACTORS AND ERRORS FOR PRODUCT QUALITY AND RELIABILITY IN THE INTEGRATED APPROACH OF PRODUCT AND PROCESS DESIGN, MAINTENANCE AND PRODUCTION
Kaunas University of Technology, Kestučio 27, 44321, Kaunas, Lithuania, E-mail: firstname.lastname@example.org
Dalia Čikotienė, Zenonas Ramonas
Globalization is the main challenge for all organizations developing and producing technical products today. This paper deals with develop an integrated approach to achieve the least manufacturing cost and delivery time to the customer applying concurrent development of product and process keeping the onward end of the maintenance and production process. In this paper, the belief and plausibility computations and forecasting according to the evidence theory for classifying product and its parts failures are also carried out to highlight the capabilities of manufacturing system aiming the highest production quality and reliability. The theoretical consumptions of this research have been checked and confirmed in case study – Large Lithuanian Company Y that develops and produces bicycles and their components. At the further work it is planned to create for each product and process failure case, the case needs to be classified in terms of causes and entered in the knowledge base (KB).
Keywords: human factors, errors, product quality, reliability, evidence theory.
USING MANUFACTURING MEASUREMENT VISUALIZATION TO IMPROVE PERFORMANCE
Itmecha Ltd., Metalų 14,
Paper discusses how manufacturing process can be measured and represented visually in order to help employees react quickly to new occurrences that may compromise effectiveness or production process itself. Suggested measurement and visualization methods include real-time manufacturing progress monitoring (internal and external logistics of materials, internal and external manufacturing progress) and real-time equipment workload monitoring (productive and unproductive work time, resource consumption effectiveness). Methods were implemented in Stevila Ltd. in the end of year 2010. According to result obtained in 2010, 2011, and 2012, proposed methods proved to be very effective in increasing production on schedule rates. Also, experiment indicates that equipment workload visualization makes manufacturing process more transparent, helps identifying issues and provides information that is vital for process improvement.
Keywords: ERP, real-time performance monitoring, measurement visualization, human behavior, CNC.
THE MOTION STORAGE CHARACTERISTICS AS THE INDICATOR OF STABILITY OF INTERNAL COMBUSTION ENGINE - RECEIVER COOPERATION
University of Technology, Wiejska Str.
Bialystok University of Technology, Wiejska Str. 45C, 15-351 Bialystok, Poland, E-mail: email@example.com
Bialystok University of Technology, Wiejska Str. 45C, 15-351 Bialystok, Poland, E-mail: firstname.lastname@example.org
In the article the attempt of using the motion storage characteristics was showed, to estimation of internal combustion engine - receiver cooperation. Basing on the external characteristics designated on chassis dynamometer, for various variants of power systems, it was tried to apply for applicability of proposed indicator. Initial analysis confirmed the usefulness of subjected characteristics, especially in the case of alternatively powered by LPG engines with extended adaptation cycle. Additionally, by using partial speed characteristics of the engine by various power degree, which simulated degrees of operational wear, the significant parameter of the motion storage characteristics was set with commonly used in engine - receiver analysis parameter, which is elasticity coefficient. The setting showed the legitimacy of designation the motion storage characteristics, whose the slope lets on one hand to evaluate the energetic parameters, on the other hand - to assess the engine - receiver cooperation stability.
Keywords: internal combustion engine, characteristics, motion storage.
THEORETICAL ASPECTS OF THE CALIBRATION OF GEODETIC ANGLE MEASUREMENT INSTRUMENTATION
Vilnius Gediminas Technical University, Saulėtekio al. 11, LT-10223 Vilnius, Lithuania, E-mail: email@example.com
Vilnius Gediminas Technical University, Saulėtekio al. 11, LT-10223 Vilnius, Lithuania, E-mail: firstname.lastname@example.org
Vilnius Gediminas Technical University, Saulėtekio al. 11, LT-10223 Vilnius, Lithuania, E-mail: email@example.com
Vilnius Gediminas Technical University, Saulėtekio al. 11, LT-10223 Vilnius, Lithuania, E-mail: firstname.lastname@example.org
There are multiple instruments directly implementing the principle of angle measurements (horizontal and vertical) for its functioning, used in geodesy, surveying and machine building (like tacheometers, theodolites, laser scanners, laser trackers etc.). As for the moment, there is no official reglamentation regarding calibration and testing of such instrumentation in entire range of the measurements, though instrumentation produce a huge number of both horizontal and vertical angular values during its normal implementation. In the paper the theoretical assumptions of such instrumentation testing and calibration together with examples of some practical tests are given.
Keywords: vertical angle, calibration, systematic errors, random error, calibration method.