·
Editors
·
Publisher
·
Peer reviewers
·
Reviewing Committee
Contents
Editors
George CONSTANTIN
Adrian GHIONEA
Series
Editorial Team
Emilia BĂLAN
Sorin Mihai CROITORU
Costel Emil COTEŢ
Editorial
Council
Traian AURITE, Alain GERARD, Csaba
GYENGE, Florin IONESCU,
Constantin ISPAS, Branko KATALINIK,
Stanislav LEGUTKO,
Aurel OPREAN, Eugen PAY, Daniel PLAY
![edit_academiei.jpg](Volume7_Issue4_2012_files/image003.jpg)
EDITURA ACADEMIEI ROMÂNE
Bucharest, 2012
University “Politehnica” of Bucharest
Machines and Production Systems Department
Splaiul Independenţei 313, sector 6
060032 Bucureşti, România
Tel: (+4021) 402 94 20
E-mail: orgcom@icmas.eu
http://www.icmas.eu
Editura Academiei Române
Calea 13 Septembrie nr. 13, sector 5
050711 Bucureşti, România
Tel.: (4021) 318 81 46, (4021) 318 81 06, Fax: (4021) 318 24 44
E-mail: edacad@ear.ro
http://www.ear.ro
Peer reviewers: Aurel
OPREAN, Alain GERARD, Daniel PLAY
Editorial assistant: Irina FILIP
Computerized editing: George CONSTANTIN, Mariana ŞERBĂNESCU
Reviewing Committee
Gheorghe
AMZA, Romania
Traian
AURITE, Romania
Dragos AROTARITEI, Romania
Laurean
BOGDAN, Romania
Octavian
BOLOGA, Romania
Ioan
BONDREA, Romania
Gheorghe BRABIE,
Romania
Daniel
BRUN-PICARD, France
Olivier
CAHUC, France
Gavrilă
CALEFARIU, Romania
Ilie
CATANĂ, Romania
George
CONSTANTIN, Romania
Costel Emil COTEŢ, Romania
Radu
COTEŢIU, Romania
Sorin Mihai CROITORU, Romania
George
DRĂGHICI, Romania
Gabriel
FUMUŞANU, Romania
Alain
GERARD, France
Adrian
GHIONEA, Romania
Marius
GURAN, Romania
Csaba
GYENGE, Romania
Florin
IONESCU, Germany
Sorin
IONESCU, Romania
Mihaiela
ILIESCU, Romania
Kostadin
KOSTADINOV, Bulgaria
Ivan KURIC,
Slovakia
Stanislav
LEGUTKO, Poland
Nicolae
MARINESCU, Romania
Josef
NOVAK-MARCINCIN, Slovak Republic
Constantin
MINCIU, Romania
Sevasti
MITZI, Grece
Vasile
NĂSUI, Romania
Adrian NICOLESCU, Romania
Tadeusy
NIESZPOREK, Poland
Nicolae
OANCEA, Romania
Viorel
PĂUNOIU, Romania
Daniel PLAY, France
Nicolae
PREDINCEA, Romania
Dan PRODAN,
Romania
Ştefan
Dan PASTRAMĂ, Romania
Tomasz
RYDZKOWSKI, Poland
Jean
François RIGAL, France
Ion
SIMIONESCU, Romania
Laurenţiu
SLĂTINEANU, Romania
Ştefan
STAICU, Romania
Constantin
STĂNCESCU, Romania
Eugen
STRĂJESCU, Romania
Ioan
TĂNASE, Romania
Miron ZAPCIU, Romania
|
Journal
PROCEEDINGS
IN MANUFACTURING SYSTEMS
□ Volume 7,
Issue 4, 2012
Contents
· Mahesh B. PARAPPAGOUDAR, Pandu R.
VUNDAVILLI,
Application of modeling tools in manufacturing
to improve quality and productivity with case study
· Yulian MLADENOV, Desislava ATANASOVA, Ivo ATANASOV,
Profiling of a disc cutter for
cutting large wheels
· Veronika IVANOVA, Krassimira KOLEVA, Radko
MIHAILOV, Iossif BENIOZEF,
Family tools for robot-assisted
laparoscopy
· Ioan DAN,
Romeo CIOARĂ,
Pre-tensioned C-frame for the crank mechanical
press. Study of the stress and strain state
· Nicolae BOIAN, Marioara Adriana BOIAN,
Diagnose of human resources of
small and middle size enterprises (SME)
· Laurenţiu SLĂTINEANU, Oana DODUN,
Margareta COTEAŢĂ,
Maricela
POIENARU, Alina OANCEA, Irina BEŞLIU,
Applying principles of axiomatic
design in the case of a device for
rotational molding
· Simeon ILIEV, Kiril HADJIEV,
Analysis of engine speed effect on
the four - stroke gdi engine performance
· Melania TERA, Octavian BOLOGA, Radu BREAZ,
Ionuţ CHERA, Sorin TÎRNOVEAN,
Study of incremental deep-drawing
of bimetallic sheets
· Todor
PENCHEV, Petar BODUROV, Dimitar Karastojanov,
New industrial engine – priority and field of
application
· Nicoleta LUNGU, Marian BORZAN,
Effect of cutting speed and feed
rate on tool geometry, temperature and cutting forces in machining
AISI 1045 carbon steel using fem
simulation
· Adrian Stere PARIS, Ioan TĂNASE, Constantin
TÂRCOLEA, Cristian DRAGOMIRESCU,
Applications of the Monte Carlo
method in the manufacturing
· Ivan Kuric, Matúš Košinár, Miroslav CIsár,
Measurement and analysis of CNC
machine tool accuracy in different location on work table
· Ion TĂNASE, Victor POPOVICI, Gheorghe CEAU,
Nicolae PREDINCEA
Cutting edge temperature prediction
using the process simulation with Deform 3D software package
· Raluca Ioana GUICA, Cristian DRAGOMIRESCU, Laura
Elena TRIFAN, Constantin Anton MICU,
A new approach of a length measuring system in
orthopedics using a laser probe
· Iulian FLORESCU, Daniela FLORESCU, Dragos Iulian
NEDELCU,
Study about the fluid losses in the
branching pipes
p. 193-198
APPLICATION OF MODELING TOOLS IN MANUFACTURING TO IMPROVE QUALITY AND PRODUCTIVITY
WITH CASE STUDY
View full text
Mahesh B. PARAPPAGOUDAR1,*,
Pandu R. VUNDAVILLI2
1) Principal
& Ph.D., Professor in Mechanical Engineering Dept, CSIT, Durg (C.G),
India
2) Ph.D,
Professor & Head, Mechanical Engineering Dept, MIC College of Technology,
Kanchikacherla, AP, India
Abstract:
The productivity improvement, especially in the manufacturing industries
helps to reduce the cost and further it assists the firms to be competitive
in the market. One of the tools which help the industries to reduce cost,
manufacturing lead time and defective products is process modeling. Hence,
the present day’s need of the market to achieve the quality with the
reduction in cost is possible with the effective utilization of modeling
tools. Many modeling and simulation
tools are available to simulate manufacturing processes. In the present
paper, both conventional regression tools (Design of Experiments, Response
Surface Methodology) as well as un-conventional modeling tools based on
Neural Networks (Back Propagation Neural Network and Genetic-Neural Network)
are discussed. All manufacturing processes can be represented as multi input
multi output system. It is important to understand the influence of process
variables and establish input-output relationships. Design of Experiments
combined with Response Surface Methodology is a powerful statistical tool to
analyze the influence of process variables and establish accurate
input-output relationships. The requirement of manufacturing processes is to
know a set of process variables, which will result in desired output (Reverse
mapping). However, most of the times the statistical tools fail in reverse
mapping. Hence, the use of soft computing based Neural Network, Genetic
Algorithm, Fuzzy Logic and their different combinations can be successfully
used in reverse mappings. The application of these tools is illustrated with
the help of a case study.
Key words: Modeling, Manufacturing Process, DOE, RSM,
NN, GA, FLC.
p. 199-204
PROFILING
OF A DISC CUTTER FOR CUTTING
LARGE WHEELS
View full text
Yulian MLADENOV1*, Desislava ATANASOVA2, Ivo ATANASOV3
1) Prof., PhD,
Lecturer, Department of MTM, Ruse University, Ruse, Bulgaria
2) Assoc.
Prof., PhD, Lecturer, Department of IIT, Ruse University, Ruse, Bulgaria
Abstract:
This article shows a principled approach through application of the method
of wrapping the treated surface in its variety - a method of coating design -
to profiling the work of the disc cutter for cutting gears with larger
modules (m≥10mm). Their requirements for accuracy and roughness of the
gears’ side surfaces are not very high, due to the nature of work, as they
are used to drive different types of drums in the cement, mining, food and
other industries.
This profiling
approach allows to be manufactured a prefabricated disk cutter, which has
some very important advantages, such as lower manufacturing cost, simple
forms of the body and teeth (usually plane and rotational), better
productivity, which is a result of sharply ground teeth.
In the paper is also shown a construction of a disk prefabricated
cutter, designed by the authors, which is used for milling of teeth of a gear
with module 20 mm (m = 20 mm).
Key words: cylindrical gear, disc cutter, large modules, profiling, structural
wrapping method.
p. 205-210
FAMILY TOOLS FOR ROBOT-ASSISTED LAPAROSCOPY
View full text
Veronika IVANOVA1,*,
Krassimira KOLEVA2, Radko MIHAILOV3, Iossif BENIOZEF4
1) (PhD student),
Department of Robotized executive mechanisms and Intelligent Systems,
Institute of Systems Engineering and Robotics Bulgarian Academy of Sciences,
Sofia, Bulgaria
2) Assistant Department of Technical Mechanics, The Technical University of Varna, Varna, Bulgaria
3) Asoc. Professor, College of Technology to The Technical
University of Varna, Dobrich, Bulgaria
4) Engineer,
Department of Robotized executive mechanisms and Intelligent Systems
Institute of Systems Engineering and Robotics Bulgarian Academy of Sciences,
Sofia, Bulgaria
Abstract: Laparoscopic surgery rapidly evolves as
minimally invasive surgery. The lack of the tactile sense is the most
important disadvantage associated with laparoscopy because it limits surgeon abilities
to diagnoses and treatment some surgical problems. The introduction of robots
in minimally invasive surgery will considerably enhance the accuracy of
medical interventions. But investigations of current robot instruments are
indicated to have some technological deficiencies the main of which are lack
of tactile sense. Research
in the area of laparoscopic tools with force measurement capabilities has led
to significant advancements over the past several years. Researchers have
retrofitted conventional laparoscopic instruments with force and position
sensors, developed novel laparoscopic tool with sensors incorporated into
their design, and have also developed entire robotic surgical systems with
force sensing/reflection capabilities. Several researchers have also
incorporated a direct sensing method for tissue characterization through
pressure measurement normal to the surface of the jaws. These methods are
expensive, none sterilizable and not modular which make them difficult to
incorporate into laparoscopic tools. To avoid cardinal problems in direct
force measurements in bloodless surgery a mechanical construction was
produced where two force sensors by Honeywell USA were incorporated. Our work
focuses on design of novel surgical instrument for laparoscopic
Cholecystectomy with force feedback control and sensors which are
incorporated in handle of tool. The paper shows also some variants of rigid
and elastic links for irregular objects manipulations.
Key words: end effectors, haptics,
surgical robots, instruments, laparoscopy.
p. 211-216
PRE-TENSIONED C-FRAME FOR THE CRANK MECHANICAL PRESS.
STUDY OF THE stress AND strain STATE
View Full TEXT
Ioan DAN1,*, Romeo
CIOARĂ2
1) PhD
student, Eng., Transilvania University of Brasov, Braşov, Romania
2) Prof., PhD, Eng., Economic
Engineering and Production Systems Department, Transilvania University of
Brasov, Braşov, Romania
Abstract:
Considering the long useful life duration of the
presses, the reduction of their energetic consumption during exploitation
turns into an essential goal. An important path for attaining this objective
is raising the rigidity of the press, which equals the consumed energy for
the elastic deformation of the machine. The paper herein submits such a new
solution of C-frame, achieved through casting and being pre-tensioned. The
C-frame of the Romanian crank press PAI 25 was taken as reference, whose general geometrical features were not modified.
Modelling the reference C-frame and the new constructive solution was
accomplished within the design environment ProEngineering WildFire 4. Both
models were subjected to the analysis with finite element, resorting to Catia
V5 R16, for determining their stress and strain state. The new constructive
solution, adequate to pre-tensioning the front pillars of the machine frame
resulted from minimally modifying the reference constructive solution. The
front pillars were very little modified in order to be tensioned through
tightening with tension-rods. For the study of the strain and deformation
state, impelling and straining with external forces were stipulated in full
accord with the real case. The study was achieved for three values of
the pre-strain generated by every tension-rod.
The paper herein submits a few results obtained with respect to
raising the rigidity of the machine frame and to reducing the tension state
within its body, through pre-tensioning its front pillars. The compared
analysis of the results clearly enhances the superiority of the new solution.
Key words: rigidity,
pre-tensioned C-frame, mechanical press, FEA, stress state, strain state.
p.
217-222
DIAGNOSE OF HUMAN RESOURCES
OF SMALL AND MIDDLE SIZE
ENTERPRISES (SME)
View Full TEXT
Nicolae BOIAN1,*, Marioara Adriana BOIAN2
1) PhD, Lecturer, department of Engineering Technology
and Industrial Management, University
“Transilvania”, Brasov, Romania
2) Head of financial accounting department, Financial Investment Company
“Transilvania” SA, Brasov, Romania
Abstract: The paper presents the main elements of human
resources diagnose as part of small enterprise resources analysis. Starting
from general knowledge regarding human resources, the diagnose objectives and
specific demands for small and middle size enterprise, this paper synthesizes
a model to be used in diagnose analysis process. According
to this model, we established a method of
evaluation for each of the three topics of human resources analysis:
structure, efficiency and behaviour. For each of these we have tables with
the main financial indicators.
A scoring evaluation method is associated to this diagnose model to
facilitate setting the business level in accordance to human resources
criterion. The score function with variables, coefficients and the main
coordinates of their choice is also presented. Following the diagnose score,
the business level is established and we suggest the main methods of
improvement regarding technical resources.
Finally, the paper presents a case study of a company in the field of
production, we assessed the business rate and set the main conclusion
following diagnose. We added the tables containing values of indicators for
the three topics and also the justification for the choice of coefficients
significance and conventional score assigned for each domain of analysis.
Key words: human
resources, personnel, diagnose analysis, professional competences, labour
productivity, labour efficiency, salary.
p.
223-228
APPLYING PRINCIPLES OF AXIOMATIC DESIGN
IN THE CASE OF A
DEVICE FOR ROTATIONAL MOLDING
View Full TEXT
Laurenţiu
SLĂTINEANU1, Oana DODUN2, Margareta COTEAŢĂ3,*,
Maricela POIENARU4,
Alina OANCEA4, Irina BEŞLIU5
1) Prof., PhD, Department of Machine Manufacturing
Technology, “Gheorghe Asachi” Technical University of Iaşi, Romania
2)
Assoc. prof., PhD, Department of Machine Manufacturing
Technology, “Gheorghe Asachi” Technical University of Iaşi, Romania
3) Lecturer, PhD, Department of Machine Manufacturing
Technology, “Gheorghe Asachi” Technical University of Iaşi, Romania
4) Master student, Department of Machine Manufacturing
Technology, “Gheorghe Asachi” Technical University of Iaşi, Romania
5) Junior Assistant, Department of Mechanics and
Technologies, University “Ştefan cel Mare” of Suceava, Romania
Abstract:
Axiomatic design is a design method
promoted and applied in the last decades in order to help the designer in
systemizing his activity, by taking into consideration some essential
principles proposed by the Korean scientist Num Suh Pyo et the end of the
previous century . On the other hand, the rotational molding is a
manufacturing method applied when hollow parts made of plastic are necessary.
The method is based on the rotation of the mold around two perpendicular
axes. The paper presents the results obtained by taking into consideration the
principles of axiomatic design in the case of a device adaptable on a
universal lathe. The device is able to facilitate the application and the
study of the rotational molding of plastic parts. The placement of the device
on a lathe should ensure a simple modification of the rotational speed. Chain
and conical gear transmissions were used to obtain the second rotational
motion. The analysis developed by means of the stages specific to the
axiomatic design facilitated the highlighting of some specific functional
requirements and practical solutions for defining the design parameters. A
matrix model was conceived by taking into consideration the functional
requirements and the design parameters. There were defined three groups of
functional requirements; uncoupled and uncoupled solutions were identified.
As direct result of applying the principles specific to the axiomatic design,
a constructive solution for a device allowing the applying of the rotational
molding was proposed.
Key words: axiomatic design, principles, rotational molding,
plastic part, device, lathe, motion transmission.
p.
229-234
ANALYSIS OF ENGINE SPEED EFFECT ON THE FOUR - STROKE
GDI ENGINE
PERFORMANCE
View Full TEXT
Simeon ILIEV1,*,
Kiril HADJIEV2
1) PhD, Assistant Prof.,
Internal Combustion Engine Department, University of Rouse, Ruse, Bulgaria
2) PhD, Assistant
Prof., Internal Combustion Engine Department, University of Rouse, Ruse,
Bulgaria
Abstract: Application of simulation codes on modeling of
thermodynamic cycle of ICE has become more important during last years. The
computational simulation model development is use for commercialization of
computational fluid dynamics software for development of internal combustion
engines performance simulation. Advances in physical models, numerical
methods and computational power together have brought large-eddy simulations
(LES) to the point where it warrants serious consideration for computing
in-cylinder turbulent flows. Recently, a simulation tools, which models the different
subsystem in an integrated manner has been developed. Analysis of the results
of the model make possible investigation of volumetric efficiency, brake
efficiency, burning rate, temperature and cylinder pressure value. The
numerical analysis and calculations demonstrates that the numerical
computational fluid dynamics (CFD) tools, at their stage of development, can
help the engine designers to obtain more complete information on direct
injection (DI) gasoline engine. For this investigation, a four-cylinder DI
gasoline engine was tested under different engine speeds. The present study
focuses on the effect of engine speed on engine performance.
Key words: Computational simulation, Engine performance,
Gasoline engine, 1D CFD, Spark ignition engine.
p.
235-240
STUDY OF INCREMENTAL DEEP-DRAWING OF BIMETALLIC
SHEETS
View Full TEXT
Melania TERA1*, Octavian BOLOGA2, Radu BREAZ3,
Ionuţ CHERA4, Sorin
TÎRNOVEAN5
1) Assist.Prof. PhD. Eng, Melania
TERA, Industrial Machines and Equipments Department, Faculty of Engineering,
"Lucian Blaga" University of Sibiu, Romania
2) Prof.PhD. Eng, Octavian
BOLOGA, Industrial Machines and Equipments Department, Faculty of
Engineering, "Lucian Blaga" University of Sibiu, Romania
3) Prof. PhD. Eng, Radu BREAZ,
Industrial Machines and Equipments Department, Faculty of Engineering,
"Lucian Blaga" University of Sibiu, Romania
4) PhD Student. Eng, Ionuţ
CHERA, Industrial Machines and Equipments Department, Faculty of Engineering,
"Lucian Blaga" University of Sibiu, Romania
5) PhD Student. Eng, Sorin
TÎRNOVEAN, Industrial Machines and
Equipments Department, Faculty of Engineering, "Lucian Blaga" University of Sibiu, Romania
Abstract: The usage, as
blanks, of bimetallic sheets it’s justified because of the addition of the
advantages offered by both materials of which it is composed and to a
reduction of the disadvantages presented by each material if taken
separately. There are cases in which certain properties are needed on the
part's outer side, while on the part's inner side there are needed very
different properties. The theoretical researches have targeted the
development of models that would allow the analysis through numerical
simulation of the behaviour of this type of blanks. Another research
direction referred to the manner of generating the shape of parts obtained
through the incremental forming process. For the experimental researches
there were employed complex trajectories for generating the part's shape. The
researches unfolded in this direction targeted a better understanding of the
influence of the punch's movement trajectory on the formability degree of
bimetallic sheets, as well as on the quality of the realised parts, on the
shape errors and on the dimensional precision.
Key words: incremental deep-drawing,
bimetallic sheets, numerical simulation, trajectories, spiral.
p. 241-244
NEW INDUSTRIAL ENGINE – PRIORITY AND
FIELD OF APPLICATION
View Full TEXT
Todor PENCHEV1,*,
Petar BODUROV2, Dimitar Karastojanov3
1) PhD assoc.
professor, Material Processing Department, Technical University – Sofia,
Sofia, Bulgaria
2) Material Processing
Department, Technical University – Sofia, Sofia, Bulgaria
3)PhD assoc.
professor, Institute of Computing and Comunication Technologies-Bulgarian
Academy of Science, Sofia, Bulgaria
Abstract:
A new industrial engine is
presented – Industrial Rocket Engine (IRE).
It was developed in Bulgaria and certified in Russia. That engine is
applicable for propelling hammering machines – a high-speed forging hammer
and a diesel hammer for pile fixing. Possibilities for broadening the
technological capabilities of these machines by the use of IRE are also shown. Better parameters of
deformation of special alloys with little plasticity and better parameters in
the production of complex shape details were achieved by using such
machienes. Using diesel pile-fixing hammer, fixing of piles at any angle can
be achieved, very important technique for landslides and earthquake region
stabilization. The IRE uses hydrogen
(gaseous or liquid) which brings ecological advantage of that industrial
engine.
Key
words: engine, impact,
impact machines, hammers.
p.
245-252
EFFECT OF CUTTING SPEED AND FEED RATE ON TOOL GEOMETRY,
TEMPERATURE AND CUTTING FORCES IN MACHINING AISI 1045 CARBON STEEL USING FEM
SIMULATION
View Full TEXT
Nicoleta LUNGU1,*,
Marian BORZAN2
1) PhD, Department of
Manufacturing Engineering, Faculty of Machine Building, Cluj-Napoca, Romania
2) Prof., PhD,
Department of Manufacturing Engineering, Faculty of Machine Building,
Cluj-Napoca, Romania
Abstract: Finite element simulation of the cutting process is
increasingly used by researches in the field to the detriment of experimental
tests because they are expensive and time consuming. Another advantage of
this method is that it provides information on deformations, stresses and
temperatures that occur during the machining process but also about chip
shape and tool wear rate. This paper studies the influence of cutting speed
and feed rate on tool geometry, temperature and cutting forces in machining
AISI 1045 carbon steel. For this research were run six trials of simulation.
The machining parameters (cutting speed and feed rate) were considered
variable and tool geometrical parameters were kept constant. Finite element
simulation was performed with the software Deform 2D Machining. Simulation
results are showing that increasing the cutting speed increases the
temperature values but the values of the cutting forces are decreasing. When
cutting with high values of the feed rate, cutting forces and temperature are
rising, causing modification of the tool geometry and thus a higher wear.
Keywords: finite element simulation, cutting process, feed rate,
Deform 2D, cutting forces, tool geometry.
p. 253-258
APPLICATIONS OF THE MONTE CARLO METHOD IN THE MANUFACTURING
PROCESSES
View Full TEXT
Adrian Stere PARIS1,*,
Ioan TĂNASE2, Constantin TÂRCOLEA3, Cristian
DRAGOMIRESCU4
1) Assoc. Prof. PhD,
Eng., TMS department, University Politehnica, Bucharest, Romania
2) Prof., PhD, Machines
and Production Systems Department, University Politehnica, Bucharest, Romania
3) Prof., PhD,
Mathematics Department, University Politehnica, Bucharest, Romania
4) Assoc. Prof., PhD,
Department of Mechanics, University Politehnica, Bucharest, Romania
Abstract: The accelerated developement of computers and software
(particularly free and open-source software) made more
accessible, for a large category of researchers and engineers, the use of
computer aided simulation techniques. In
general terms, the Monte Carlo Method (MCM) or Monte Carlo Simulation (MCS)
can be used to describe any technique that approximates solutions to
quantitative problems through statistical sampling The Monte Carlo
simulation has important applications for discret-event systems (usual in
manufacturing), stress/strength stochastic modeling (in design), reliability, maintainability and availability
evaluation. Simulation in system reliability analysis is based on the MCS
method that generates random failure times from each component's failure
distribution. As practical exemplification the paper presents a few Monte
Carlo simulation procedures and a manufacturing case study.
Key words: simulation, Monte Carlo method, discret-event system, manufacturing.
p. 259-264
Measurement and analysis of CNC machine tool accuracy in different location
on work table
View Full TEXT
Ivan Kuric1,*, Matúš Košinár2, Miroslav CIsár3
1)
PhD,
Prof., Eng., Department of Automation and
Production Systems, University of Zilina, Slovak Republic
2)
PhD,
Eng, Department of Automation
and Production Systems, University of Zilina, Slovak Republic
1)
Ing., Eng, Department of Automation
and Production Systems, University of Zilina, Slovak Republic
Abstract:
Machine
tool accuracy is characterized by the ability of the machine to produce parts
of the required shape and dimensions keeping the required tolerances and to
achieve the desired surface roughness. Requirements for accuracy of the machine
tools result from the required precision of components manufactured on the
machine. Geometric accuracy of the machine tool is the precision of shape and
position of its individual parts and their mutual movements. Accuracy of parts machined on CNC machines depends crucially on
the machine accuracy. The paper deals
with possibility of geometrical accuracy monitoring of CNC machine tools with
Renishaw Ballbar QC 20 in different locations at the work table. Renishaw's
QC20 Ballbar is a linear displacement sensor based tool that provides a
simple, rapid check of a CNC machine tool's positioning performance to
recognized internationals standards. QC20 Ballbar system is a CNC machine
tool diagnostic system. It was compared machine accuracy during the operation
in three different positions of work table: central, left side, right side at
the different speed. It was analysed the accuracy in these different places.
The measurement was performed on milling machine tool Haas VF – 4DHEv
Key
words: machine toll,
diagnostics, roudness deviation, measurement, Ballbar QC20.
p. 265-268
CUTTING EDGE TEMPERATURE PREDICTION USING THE PROCESS
SIMULATION WITH DEFORM 3D SOFTWARE PACKAGE
View Full TEXT
Ion TĂNASE1,*,
Victor POPOVICI2, Gheorghe CEAU3, Nicolae PREDINCEA4
1) Prof., The
Machines and Manufactured Systems Department, University “Politehnica” of
Bucharest, Romania
2) Prof., The
Technology of Materials and Welding Department, University “Politehnica” of
Bucharest, Romania
3) Eng., General Logistics
Department, Ministry of Administration and Interior, Romania
4) Prof., The
Machines and Manufactured Systems Department, University “Politehnica” of
Bucharest, Romania
Abstract:
High speed machining is submitted
to economical and ecological constraints. Optimization of cutting processes
must increase productivity, reduce tool wear and control residual stresses in
the workpiece. Modeling, as close to reality of the cutting process, cannot
be done without taking into account thermal phenomena. On the one hand,
material mechanical parameters depend greatly on temperature (although it is
difficult to obtain actual values of this dependence) and on the other hand,
a decisive role is played both by the thermal regime of cutting speed,
through component vg - chip speed tool rake face – and by the amount of heat
that occurs in the area of occurrence and formation of the chip. This paper
proposes a new approach for describing the friction behaviour at the
tool–chip interface in the area near the cutting edge.
Key
words: tool-chip interface, cutting models, process simulation 3D, global heat transfer coefficient.
p. 269-267
A NEW APPROACH OF A LENGTH MEASURING SYSTEM IN
ORTHOPEDICS USING A LASER PROBE
View Full TEXT
Raluca Ioana GUICA1,*,
Cristian DRAGOMIRESCU2, Laura Elena TRIFAN3, Constantin
Anton MICU4
1) Asist. PhD Student,
eng, Faculty of Engineering in Foreign Languages, University “Politehnica” of
Bucharest, Bucharest, Romania
2) Conf. PhD, eng,
Faculty of Biotechnical Systems Engineering , University “Politehnica” of
Bucharest, Bucharest, Romania
3) Asist. PhD Student,
eng, Faculty of Engineering in Foreign Languages, University “Politehnica” of
Bucharest, Bucharest, Romania
4)Prof. PhD, eng,
Faculty of Mechanics and Mechatronics, University “Politehnica” of Bucharest,
Bucharest, Romania
Abstract:
This paper aims to present a new
model of a length measuring system in orthopedics using a laser probe. A
study of the current measuring methods in orthopedics revealed the need of an
accurate, easy to use device, whose production or operating costs are not
very high, and that doesn’t expose both pacient and doctor to radiation. In
order to achieve this requirements several researches upon different possible
models were done. The devices are basen on coordinate metrology, that has
reached a high level of accuracy. This paper will present one of the
theoretical models, trying to define a certain point of the laser beam, so
that in any moment, the doctor to be able to measure the distance between two
points, thus achieving, for example, the length of a leg. When the best solution
will be found, the device will be built and used both in clinical and
intraoperative assesment.
Key words: length measuring, laser probe, coordinate measuring
machine, orthopedics, leg length discrepancy.
p. 275-279
Study about the FLUID losses IN the branching pipes
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Iulian FLORESCU1,*,
Daniela FLORESCU2, Dragos Iulian NEDELCU3
1) Professor., PhD,
Faculty of Engineering, “Vasile Alecsandri” University of Bacau, Romania
2) Associate
professor, PhD, Faculty of Engineering, “Vasile Alecsandri” University of
Bacau, Romania
3) PhD, Faculty of
Engineering, “Vasile Alecsandri” University of Bacau, Romania
Abstract:
This paper aims to determine the
losses of branched pipe sections according to the ratio of flow areas,
inclination of the adjacent pipe, and source flows ratio.
This paper proposes a method for analyzing
the dynamics of real fluid flow through pipe bends. The method can contribute
to an optimal design of pipe networks. Along with linear load losses, local
losses are particularly important for these piping systems, their analysis
for determining coefficients of load losses being of prime importance. Besides
the classical experimental attempts to study these tests we can try a method
of theoretical analysis based on flow simulation, more accessible to
different variants of the pipes. The variation of major structural and
functional parameters of the flow is emphasized by the simulation of the
flow. We can determine areas of hydraulic energy losses and can appreciate
the value of the main flow parameters. Simulations
were performed using Fluent 6.3
software and digital data were processed for obtaining graphs with Mathcad
14. Piping systems were represented with SolidWorks program. The Flow
simulation allows an analysis of current lines, areas of turbulence and
highlighting the hydrodynamic parameters of flow.
Key
words: fluid loss, dead
flow, wavy flow, cross section, input/output flow.
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