Nicoleta GILLICH


32-59 EFICIENŢA DIFERIŢILOR ESTIMATORI AI DISIMILARITĂŢII UTILIZAŢI ÎN DETECTAREA DEFECTELOR

THE EFFICIENCY OF SEVERAL DISSIMILARITY ESTIMATORS USED IN DAMAGE DETECTION

 

This paper deals with damage detection methods based on interpreting the results of vibration measurement. We briefly described an own method for damage evaluation, which takes into account a large number of frequencies achieved from weak axis bending modes. This allows the precise location of the defect location. We represented two histogram types, one with measurements and several resulted from calculations for possible damage scenarios. The damage location was determined with three estimators, among those the best results being attained with the Minkowski distance.

 

Keywords: damage, severity assessment, natural frequencies, vibration

Cuvinte cheie: defecte, evaluarea severității, frecvenţe naturale, vibraţii

Descarcare text


31-41 ANALIZA EFECTULUI CORONA ÎN REGIM TRANZITORIU DE SUPRATENSIUNE

CORONA EFFECT IN TRANSIENT REGIME OF OVERVOLTAGES

 

The paper treats the quantitative and qualitative influence of Corona discharge on waveform in transient regime of over voltages propagation on electric aerial lines. The theoretical consideration given in the paper was compare with some measurements on real distribution line and results a satisfactory validity.

 

Keywords: Corona, overvoltage transient

Cuvinte cheie: efect Corona, supratensiuni, regim tranzitoriu

Descărcare text


30-31 REGLAJUL DE STARE PENTRU PROCESE PT2 FOLOSIND MEDIUL SCILAB/XCOS

STATE CONTROL FOR A PT2 PROCESSES USING
SCILAB / XCOS ENVIRONMENT
This work aims to present the state control of a PT2 process, realizing
the numerical application, based on the Scilab/Xcos environment. Starting from
the model of state space representation for LTI systems, the controllability
property of the control system is checked, and based on the signal diagram of
state control is highlighted through simulation the step response for different
parameters respectively the pole-zero plan.
Keywords: state control, PT2 process, state space model, step
response, Scilab/Xcos environment
Cuvinte cheie: Regla

Descărcare text


29-86 METODE DE EVIDENŢIERE A FRECVENŢELOR APROPIATE

METHODS TO HIGHLIGTH CLOSE FREQUENCY
This paper offers an overview of simpler methods to accurately
estimate frequencies. In standard signal processing, the precision of frequency
estimation increases once the frequency resolution is improved. A finer
resolution is achieved by increasing the observation time interval. If this cannot
be done, the signal length can be artificially extended through the so-called
”zero-padding” method, by adding a number of samples with null amplitude.
The methods have been tested for concrete cases, using the signal processing
tool offered by the open source software, Scilab.
Keywords: signal processing, spectral analyze, “zero-padding” method,
Scilab environment
Cuvinte cheie: procesarea semnalelor, analiza spectrală, metoda
“zero-padding”, mediul Scilab

Descărcare text


27-41 MODELAREA FIZICĂ A EFECTULUI CORONA LA TENSIUNE ALTERNATIVĂ

CORONA PHISICAL MODEL IN ALTENATIVE VOLTAGE
Corona discharge around power lines leads to line parameter alternation as an electric charge is formed around the wires. In transient states, such alternations result in faster damping of oscillations while in steady regime lead to additional energy losses. The paper treats the physical Corona modelling and the analytical transients process of voltages and currents on the proposed model.
Keywords: model, Corona, electronic scheme
Cuvinte cheie: model, efect Corona, schemă electronică

Descarcare text


27-40 CALCULUL PIERDERILOR DE PUTERE DATORATE EFECTULUI CORONA

CASLCULUS OF ELECTRIC POWER LOSSES
DUE TO CORONA EFFECT
The paper present the properly designed for Corona model required to produce reasonably close modelling of electric power losses on very high electric lines. Corona modelling has been approached by means of analogue physical or mathematical modelling is treated herewith.
Keywords: power losses, method, Corona, power lines
Cuvinte cheie: pierderi de putere, metodă, efect Corona, linii electrice

Descarcare text


25-41 ANALIZA SIGURANŢEI ÎN FUNCŢIONARE A STAŢIILOR ELECTRICE

RELIABILITY STUDY OF ELECTRIC POWER STATIONS
The paper treated the main aspects regarding the reliability of
electric stations from power electric energy system of Electrica S.A. Resita,
with modern techniques for diagnosis and maintenance. It has been
considered useful to treat the electric energy system with equivalent
structural diagram method for reliability indicators calculus using the
MathCAD medium.
Keywords: reliability, method, equivalent element, indicators
Cuvinte cheie: fiabilitate, metodă, element echivalent, indicatori
Descarcare text


24-1 METODE STATISTICE APLICATE ÎN STUDIUL FIABILITĂŢII SISTEMELOR TEHNICE

STATISTICS METHODS APPLIED TO RELIABILITY
ENGINEERING
The analysis of system reliability often requires the use of subjective
judgments, uncertain data and approximate system models. By allowing
imprecision and approximate statistic methods provides an effective tool for
characterizing system reliability.
Cuvinte cheie: metodă, statistică, fiabilitate, sisteme tehnice, calitate
Keywords: method, statistics, reliability, technical systems, quality

1 METODE STATISTICE APLICATE ÎN STUDIUL FIABILITĂŢII SISTEMELOR TEHNICE


21-82 UTILIZAREA METODEI MEDIILOR ARITMETICE LA PRELUCRAREA DATELOR EXPERIMENTALE

THE USE OF ARITHMETIC MEAN METHOD FOR
EXPERIMENTAL DATA PROCESSING
The paper presents an application of the arithmetic mean method
applied to experimental data processing gained from vibration measurement on
a SN400x1500 lathe in four manufacturing cycles and using four cutting
regimes for each cycle.
Cuvinte cheie: metodă, medii aritmetice, date experimentale, serii
bidimensionale
Keywords: method, arithmetic average, experimental data, twodimensional
series

82 UTILIZAREA METODEI MEDIILOR ARITMETICE LA


22-20 ANALIZA FEM A SISTEMELOR DE IZOLARE SEISMICĂ CU SUPRAFAŢA DE ALUNECARE GENERATĂ DE FUNCŢII POLINOMIALE

Earthquake isolation systems are devices located at the base of
overhead structures (civil works), which have the goal to take off the oscillating
period of this compared with ground, during an earthquake and decrease the
transmitted energy using frictional dissipation. The results of the study
presented of this paper relieve the possibility of using sliding surfaces
generated by polynomial functions by using an intermediate neoprene element
between the sliding surface and the slider.
Cuvinte cheie: izolator seismic, pendul cu fricţiune, neopren, funcție
polinomială, analiză FEM
Keywords: seismic isolation, friction pendulum, neoprene, polynomial
function, FEM analysis

20 ANALIZA FEM A SISTEMELOR DE IZOLARE SEISMICĂ