Vasile IANCU


35-59 ÎMBUNĂTĂȚIREA CITIRII ÎN PLANUL TIMPFRECVENȚĂ A SEMNALELOR FOLOSITE PENTRU A DETERMINA COEFICIENTUL DE RIGIDITATE DINAMIC

IMPROVING THE TIME-FREQUENCY READING OF THE SIGNALS USED TO DETERMINE THE DYNAMIC STIFFNESS COEFFICIENT

The objective of the paper is to describe and determine the Fourier transform to define a passage relation of a signal from the time domain to a frequency domain. The process allows the identification of frequencies but does not provide complete information about the behavior of the system, in the sense that it does not allow the interpretation of frequency evolution over time. For this reason, I propose the use of time-frequency analysis.

Keywords: reading, signal, time-frequency, stiffness Cuvinte cheie: citire, semnal, timp-frecvență, rigiditate

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34-35 MODELAREA FENOMENELOR VIBRATORII LA SOLICITĂRI DINAMICE DE CONTACT ÎN RULMENŢII RADIALI

THE FLATTENING OF THE SPIRAL CASING SHELLS USING THE SOLIDWORKS SHEET METAL MODULE
The vibratory phenomena of bearings even appear even their surfaces are perfect. These vibrations are caused by the rotation of a finite number of rollers required between the two rings. Obviously, depending on the processing conditions, certain irregularities may occur. These irregularities lead to a series deviations from the normal contact between the rollers and the bearing rings. Two models of radial vibration: oval and triangular were studied.
Keywords: radial vibration, undulation, imperfections, stiffness
Cuvinte cheie: vibraţie radială, ondulaţie, imperfecţiuni, rigiditate

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34-34 INFLEUNȚA FRECVENȚELOR PROPRII ASUPRA GRINZILOR PLANE CU ZĂBRELE

INFLUENCE OF OWN FREQUENCIES
ON THE PLANE TRUSSES
In the paper is presented the way in which the own frequencies influence the good functioning of the plane trusses. The four types of trusses: Howe, Pratt, Warren with and without vertical beams were built and modeled with finite elements using the SolidWorks program. The experimental analysis was carried out on the particular stand developed for this kind of trusses. For the acquisition and processing of data, I use Kistler accelerometers and the LabVIEW program.
Keywords: truss, parallel soles, vibration, vertical beam
Cuvinte cheie: grindă cu zăbrele, tălpi paralele, vibrație, montant

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32-61 ANALIZA STĂRII DE TENSIUNI ŞI DEFORMAŢII ÎN CORPURILE DE RULARE DE MICI DIMENSIUNI

STRESS AND STRAIN ANALYZE OF

SMALL ROTATION BODIES OF BEARINGS

 

In the paper is presented the study of tensions and strains ho appears in small radial roller bearings during the compressive strength testing caused by forces acting perpendicular to the roller generator. For modelling a roller bearing Ø 16×24 [mm] we used SolidWorks program, the tests were conducted on two types of rollers with and without defect loaded in five-speeds charging.

 

Keywords: reel, bearing, local deformation, finite element

Cuvinte cheie: rolă, rulment, deformaţie locală, elemente finite

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32-60 STUDIUL STĂRII DE TENSIUNI ȘI DEFORMAȚII ALE ROLELOR DE RULMENT PRIN MODELARE CU METODA ELEMENTELOR FINITE

STRESS AND STRAIN STUDY OF THE ROLLER BEARINGS USING FEM METHOD

 

This paper aims to study the stresses and strains that occur in small radial bearings with rolls of Æ 7,5×15 mm diameter. We have considered five-speed charging for two distinct cases: without and with defects.

 

Keywords: roller bearing, contact voltage, strain, roll flange

Cuvinte cheie: rulment radial, tensiune de contact, deformație, rolă-placă plană

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32-10 MODUL DE RECONDIȚIONARE A UNOR AGREGATE CE ECHIPEAZĂ STAȚIILE DE POMPARE

RECONDITIONING MODE OF AGGREGATE WHAT

EQUIPS PUMPING STATIONS

 

There are presenting a new way to increase the pumping efficiency in many pumping station, concerning in pumps working service life optimization. This objective is rational according to the demand to not make inopportune investments (premature or expensive) by replacing or rehabilitating less used pumps. Other reason is to minimize or eliminate, as it possible, to keep on function massive used pumps with low efficiency.

 

Keywords: pump, rotor, reconditioning, CERAMITHECH

Cuvinte cheie: pompă, rotor, recondiționare, CERAMITHECH

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29-87 INFLUENȚA RIGIDITĂȚII MECANICE ASUPRA FRECVENȚELOR PROPRII DE VIBRAȚIE A CADRELOR METALICE

THE INFLUENCE OF MECHANICAL STIFFNESS ON EIGEN
FREQUENCIES OF VIBRATION AT METAL FRAMES
This paper presents a study regarding the changes of the natural
frequency of trusses due to stiffness increase. The finite element analysis was
performed, considering a constantly increasing of stiffness of frame. In this way,
the correlation between frequency changes in the transversal vibration modes
and stiffness for the studied frames is highlighted.
Keywords: stiffness, eigen frequency, vibration mode, FEM
Cuvinte cheie: rigiditate, frecvente proprii, moduri de vibraţie, MEF

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29-85 DIMINUAREA DEFECTELOR CE APAR ÎN PROCESUL DE FABRICAȚIE AL ROLELOR DE RULMENT

SHRINKING FAILURE OCCURRING MANUFACTURING
PROCESS OF ROLLER BEARINGS
This paper contains a brief overview of the flow of production of roller
bearings that equip radial model practiced by the firm INA/Germany. The focus
is on defects occurring in different phases that are unusable respective rolls. Is
a case study and propose a method of reducing the defects reported
Keywords: radial roller bearing, INA/Germany, polishing process
Cuvinte cheie: rulment radial cu role, INA/Germania, procedeu de
lustruire

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29-82 STUDIUL CIOCNIRII ROLELOR DE RULMENT RADIAL PRIN METODE NUMERICE DE CALCUL

BALL BEARINGS RADIAL COLLISION STUDY
BY NUMERICAL CALCULATION
The paper shows that the wheels now fitted radial bearings collide
during the manufacturing process. As a result of this rolls surface defects occur
due to collision elastic-plastic material. For different cases of collision was
made a study on the state of stresses and strains using the Finite Element
Method.
Keywords: radial roller bearing, Elastoplast’s clash, finite element
method
Cuvinte cheie: rulment radial cu role, ciocnire elasto-plastică, metoda
elementelor finite

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27-80 ÎNCERCAREA DE COMPRESIUNE A BILELOR DE RULMENT

THE COMPRESION TEST OF THE BEARING BALLS
The compression test of the bearing balls is not included in the category of classic methods this is regulated by normative like (STAS or ISO). They appear as a necessity where developed and manufactured various kinds of bearings. In this perspective the paper presents the concept of a specialized device for applying a compressive force to the bearing balls of different sizes, and some half-ball.
This makes it possible experimental research of the state of stress and strain that occurs in ball bearing in compression during operation using various methods like: electric resistive strain and/or photo elasticity (fotostress).
Keywords: ball bearing, compression, specialized device
Cuvinte cheie: bilă, rulment, compresiune, dispozitiv specializat

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26-75 CONSIDERAŢII PRIVIND CALCULUL DE REZISTENȚĂ AL TRANSMISIILOR PLANETARE

CONSIDERATIONS ON THE RESISTANCE CALCULATION OF PLANETARY TRANSMISSIONS
At the design of the gears from a planetary transmission, there appear some differences compared to the cylindrical or helical gears. Furthermore the crown gear is of particular importance in the calculation of these transmissions. A reduction in the thickness of the crown gear, in order to ensure certain elasticity, leads to a reduction of the total mass and to a better distribution of the load in a planetary transmission, but with the disadvantage that the load increases in the foot of the gear crown. Therefore, the calculation of the crown gear resistance increased in complexity and importance.

Keywords: Planetary transmission, voltages, calculation of resistance

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26-70 ANALIZA COMPORTĂRII LA FIERBERE A PASTELOR AGLUTENICE DIN OREZ, PORUMB, HRIŞCĂ ŞI SOIA

BOILING BEHAVIOR ANALYSIS OF GLUTEN-FREE PASTA OF RICE, CORN, BUCKWHEAT AND SOYBEANS
In this paper is presented the boiling analysis of gluten-free pasta made by rice, corn, buckwheat, soybeans and the effects on them such as: their bonding the agglomeration tendency, boiling water sediment.
Keywords: gluten-free pasta, rice, boiling, consistency

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26-35 TRANSMISIBILITATEA VIBRAŢIILOR PROVOCATE DE SISTEMELE DE ACŢIONARE ŞI IZOLAREA ACESTORA

VIBRATION TRANSMISSIBILITY CAUSED BY DRIVE
SYSTEMS AND THEIR ISOLATION
The paper present capability of different materials to diminish the
transmissibility of vibrations caused by diverse machineries, in order to
increases the operational safety, protect the operators against dangerous
vibration effects and improve the equipment’s performances.
Keywords: transmissibility, sponge, polystyrene, rubber
Cuvinte cheie: transmisibilitate, burete, polistiren, cauciuc
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25-66 STUDIUL COMPORTĂRII STRUCTURILOR IZOLATE CU SISTEME PENDULARE

STUDY OF THE BEHAVIOUR OF STRUCTURES
INSULATED WITH FRICTION PENDULUM SYSTEMS – II
The earthquakes have been, and are a great danger against humanity.
The study presented in this paper aims to determine the response of an
insulated structure due to earthquakes vibration loads, which are randomly,
non-periodic and contain various frequencies. The study, made on a two-story
structure involved finite element analysis, to determine the displacements,
velocities and accelerations in various locations on the structure. The actual
results were obtained using statistical methods, in order to determine the
dynamic behaviour of a vibrating structure.
Keywords: base isolation, friction, pendulum, structure
Cuvinte cheie: izolator seismic, frecare, pendul, structură
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25-65 STUDIUL COMPORTĂRII STRUCTURILOR IZOLATE CU SISTEME PENDULARE CU FRECARE Partea I-a

STUDY OF THE BEHAVIOUR OF STRUCTURES INSULATED
WITH FRICTION PENDULUM SYSTEMS – I
The earthquakes have been, and are a great danger against humanity.
The study presented in this paper aims to determine the response of an
insulated structure due to earthquakes vibration loads, which are randomly,
non-periodic and contain various frequencies. The study, made on a two-story
structure involved finite element analysis, to determine the displacements,
velocities and accelerations in various locations on the structure. The actual
results were obtained using statistical methods, in order to determine the
dynamic behavior of a vibrating structure.
Keywords: base isolation, friction, pendulum, structure
Cuvinte cheie: izolator seismic, frecare, pendul, structură
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25-64 STUDIUL COMPORTĂRII DINAMICE A STÂLPILOR CU DIFERITE NIVELE DE ÎNCĂRCARE

A STUDY REGARDING THE DYNAMIC BEHAVIOR OF
COLUMNS SUBJECTED TO DIFFERENT TIP MASSES
The present study aims to highlight the effect of a tip mass upon the
behavior of columns. We have first analytically determined, for a specific
column, the critical buckling force to find the range in which it works in the
elastic domain. Afterwards, by means of numerical simulations, we performed
analysis regarding the influence of loads due to different additional masses and
have identified the effect upon the natural frequencies and modal shapes,
concluding that the higher the mode number, the higher the influence.
Keywords: column, buckling, natural frequency, simulation
Cuvinte cheie: stâlp, flambaj, frecvenţe proprii, simulare
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23-65 ANALIZA DISPOZITIVELOR DE IZOLARE SEISMICĂ DIN ELASTOMERI FĂRĂ ŞI CU INIMĂ DE PLUMB

ANALYSIS OF ELASTOMERIC INSULATORS
WITHOUT AND WITH LEAD HEART
Seismic isolation using neopren rubber bearings or lead rubber bearings
is achieved by inserting these devices between the infrastructure and the
superstructure in order to retrieve and dissipate seismic energy so that the
constructions will not by damage.
These devices are designed and built according to the size, complexity,
degree of loading and seismic zone where the construction will be located.
Cuvinte cheie: izolator, elastomer, inimă de plumb, rigiditate
Keywords: insulator, elastomer, lead heart, stiffness

23-65 ANALIZA DISPOZITIVELOR DE IZOLARE SEISMICĂ


22-18 ANALIZA IZOLATORILOR ELASTOMERICI UTILIZÂND METODA ELEMENTELOR FINITE

Modern design methods require in certain phases the use of finite
element analysis, which allows development of safe projects in terms of
structural strength and durability. Using this analysis in the design process
provides the following advantages: cost reduction and production design,
material economy, recognizing weaknesses, quality design and construction
optimization. The paper presents an innovative base isolation device based
with increased number of adjustable parameters, for which good simulation
results were obtained.
Cuvinte cheie: analiză, element finit, izolarea bazei, elastomer
Keywords: analysis, finite element, base isolation, elastomeric

18 ANALIZA IZOLATORILOR ELASTOMERICI