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Journal PROCEEDINGS IN MANUFACTURING SYSTEMS |
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ISSN 2343–7472 ISSN-L 2067-9238 |
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Journal PROCEEDINGS IN MANUFACTURING SYSTEMS
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Volume 16, Issue 1, 2021
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Vidosav MAJSTOROVIC, Dusan STANIC, Slavenko STOJADINOVIC,
Towards a digital measurement twin based on CMM
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Laurenţiu SLĂTINEANU, Bruno RĂDULESCU, Oana DODUN, Adelina HRIŢUC,
Preliminary synthesis of a device for simulating the self-induced
vibrations when cutting
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George CONSTANTIN, Anca BUCURESTEANU,
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Tiberiu DOBRESCU, Cristina ICOCIU, Cătălin SILVESTRU, Nicolae
POSTĂVARU,
Reconfiguring the curricula so that all educational pathways allow access
to a higher form of training and qualification
·
Dragos AROTARITEI, Corina CONSTANTIN, George CONSTANTIN,
Variable importance analysis for a cutting process model
Towards a digital measurement twin based on CMM
Vidosav MAJSTOROVIC1,*, Dusan STANIC2, Slavenko STOJADINOVIC3
1)
Full Professor, Faculty of Mechanical Engineering, Department for Production
Engineering, Belgrade, Serbia
2)
MSc, Faculty of Mechanical Engineering, Department for Production
Engineering, Belgrade, Serbia
3)
Assistant Professor, Faculty of Mechanical Engineering, Department for
Production Engineering, Belgrade, Serbia
Preliminary synthesis of a device for simulating the
self-induced vibrations when cutting
Laurențiu SLĂTINEANU1,
Bruno RĂDULESCU2, Oana DODUN1,*, Adelina HRIȚUC4
1)
Prof., PhD, Department of Machine Manufacturing Technology, “Gheorghe Asachi”
Technical University of Iași, România
2)
Lecturer, PhD, Department of Machine Tools and Tools, “Gheorghe Asachi”
Technical University of Iași, România
3)
Prof., PhD, , Department of Machine Tools and Tools, “Gheorghe Asachi”
Technical University of Iași, România
4)
Ph.D. student, Department of Machine Manufacturing Technology, “Gheorghe
Asachi” Technical University of Iași, România
Abstract:
To explain how to generate self-induced vibrations in
a cutting process, there are currently several hypotheses and mathematical
models. Such a model is known as a mass-spring system on a moving belt. In
principle, the model of the mass–spring system on a moving belt took into
consideration the action of the frictional force generated by the movement
of a part having a certain mass on the surface of a continuous belt wrapped
in two wheels, one of which is a drive wheel. The part is supported
laterally, in the direction of movement, by two springs. Using principles
from axiomatic design, the paper proposes a variant of the device that
considers the mass–spring system but with the use of a rotational motion
instead of the motion along a linear trajectory. Functional requirements
have been defined for this purpose, and appropriate solutions have been
identified for meeting each of the functional requirements. An adaptable
device has been designed as such on a universal lathe. A
parallelepiped-shaped part pressed against the outer cylindrical surface of
a ring-type part is used. Attention was paid to the possibilities of
changing the values of some input factors to reveal the influence of these
factors on some characteristics of the self-induced vibrations. Factors
whose values may change are considered the peripheral speed of the ring-type
part, the forces generated by the springs involved in the vibratory motion,
the pressure force of the parallelepiped on the outer cylindrical surface of
the ring.
Aspects regarding the
remanufacturing of heavy-duty machine tools from the perspective of
sustainable development
George CONSTANTIN1,*, Anca BUCUREȘTEANU2
1, 2) Prof., PhD, Eng., Robots and Manufacturing Systems Department,
University "Politehnica" of Bucharest, Romania
Abstract: In this paper, the authors present some aspects regarding the redesign and remanufacturing of heavy-duty machine tools from the perspective of compliance with the requirements of operator and environmental protection, according to the principles of sustainable development. There are aspects regarding the reduction of material consumption, reduction of expenses due to the consumption of oil, water and electricity, reduction of noise pollution, all in the conditions of finally obtaining modern CNC machine tools, which can compete with new machine tools.
Reconfiguring the curricula so that all educational pathways
allow access to a higher form of training and qualification
Tiberiu DOBRESCU1,*,
Cristina ICOCIU2, Cătălin SILVESTRU3, Nicolae
POSTĂVARU4
1)
Prof., PhD, Robots and Manufacturing
Systems Department, University "Politehnica" of Bucharest, Romania
2) Assoc.
Prof., PhD, Robots and Manufacturing Systems Department, University
"Politehnica" of Bucharest, Romania
3) Assoc.
Prof., PhD, Robots and Manufacturing Systems Department, University
"Politehnica" of Bucharest, Romania
4) Prof.,
PhD, Metal structures, Management and Graphic Engineering Department,
Technical University of Civil Engineering Bucharest, Romania
Abstract:
The article includes statistical
research of European documents and studies conducted by psychologists and
sociologists, which propose a new education system based on the individual's
freedom to choose when he wants to learn and based on his innate qualities,
skills and abilities that should be developed in life for bringing
satisfaction. What follows until 2030-40 is completely different from what
it was in the last hundred years, generation Z and Alpha differ from the
rest by their nature, they have a different behavioral profile. Those who
deal with the education system today should listen to behavioral specialists
and be supported to change the system in the way they and tomorrow's
generations want, otherwise, education will not achieve its goal. In the
spirit of those presented, of sociological and psychological studies /
articles developed by renowned teachers, we further present the proposed
scheme for the new education system that can be applied starting with 2023,
if we hurry to legislate and adapt to European strategic requirements.
Variable importance analysis for a cutting process model
Dragos AROTARITEI1,*, Corina BOTEZ (CONSTANTIN)2, George CONSTANTIN3
1)
PhD, Prof., Medical Bioengineering Faculty, University of Medicine and
Pharmacy ”Grigore T. Popa”, Iasi, Romania
2)
PhD, Assistant Prof., Engineering Graphics and Industrial Design Department,
University “Politehnica“ of Bucharest, Romania
3)
PhD, Prof., Machine and Production Systems Department, University
“Politehnica“ of Bucharest, Romania
Abstract:
The
mathematical modelling and analysis of the milling process still remains a
challenge for researchers. The usually way to do that is to discover
mathematical functions that approximate the cutting forces as function of
three variables: cutting depth, feed per tooth and cutting speed. Finding a
position is very difficult, although some proposals are made in very few
works. A black box modelling is an attractive idea but, in this case, the
eventual connections of model with physical phenomena can be lost. This
paper proposes an importance analysis for input variables using model based
on average and maximum cutting forces on three axes. Two methods are used
for this global sensitivity analysis (GSA), the Morris method and Sobol
methods. The milling investigations were carried out on a CNC machining canter, FIRST
MCV 300, with three NC axes. The measurements were made with a Kistler
dynamometer fixed on the machine tool table. The workpiece material used for the experimental tests is improved AISI 1045
steel. The workpiece was initially tested in order to establish the material
(spectrometric test and hardness measuring). The cutting tool used is
CoroMill R 365-080Q27-S15M with cutting tool inserts R365-1505ZNE-PM 4230
from Sandvik Coromant. Because the data are already collected, in order to
find the new values necessary for GSA, a model based on RBF networks is
proposed to be used.
Electronic mail: orgcom@icmas.eu |
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