Pavel TRIPA


27-75 STUDIUL DURABILITĂŢII CONDUCTELOR PE BAZA CONCEPTELOR MECANICII RUPERII

THE STUDY OF DURABILITY PIPES BASED ON FRACTURE
MECHANICS CONCEPTS
The paper describes the lifetime analysis of steam pipes subjected to
internal pressure by applying the concepts of Fracture Mechanics of materials.
It also presents the durability analysis of a pipeline with semi-elliptical
longitudinal crack subjected to internal pressure.
Keywords: pipe internal pressure, crack, durability, ego
Cuvinte cheie: conductă, presiune interioară, fisură, durabilitate,exemplu

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27-74 APRECIEREA COMPORTĂRII CONDUCTELOR FISURATE PRIN CRITERIILE MECANICII RUPERII

ASSESSMENT OF CRACKED PIPES BEHAVIOR BY FRACTURE MECHANICS CRITERIA
The paper presents the methods used to assess the behaviour of cracked pipes subjected to internal pressure by applying the Linear Elastic Fracture Mechanics criteria (LEFM). It is also described an analysis of a cracked steam pipe used in Romanian power plants.
Keywords: fracture mechanics, pipe, fracture toughness, heat resistant steel
Cuvinte cheie: mecanica ruperii, conducte, tenacitate la rupere, oţel termorezistent

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25-67 CÂTEVA ASPECTE ALE ESTIMĂRII TENACITĂŢII LA RUPERE PENTRU OŢELUL 12H1MF

SOME ASPECTS OF ESTIMATING THE FRACTURE
TOUGHNESS FOR 12H1MF STEEL
Between main characteristics, praising the fracture toughness of
materials, there are different relations. The present paper is praising some
difficulties which concerning the fracture toughness, on the basis of a method
which allow to estimate another characteristic, much easy to determine.
Keywords: steam pipe, toughness, steel 12H1MF
Cuvinte cheie: conductă de abur, tenacitate la rupere, oţel 12H1MF
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19-96 FACTORUL DE INTENSITATE AL TENSIUNII (KI) PENTRU O CONDUCTĂ DE ABUR SUPUSĂ NUMAI LA ŞOC TERMIC (ΔθS)

STRESS INTENSITY FACTOR (KI) FOR A STEAM PIPE
SUBJECTED ONLY TO THERMAL SHOCK (ΔθS)
The temperature of a steam pipe is variable because of the steam
pressure variation inside of it. If the steam temperature variation takes place
during a short time, the steam is subjected under a thermal shock. The effect of
the thermal shock is superimposed on the effect of the mechanical load, going
to an additional load on the pipe. The thermal shocks are dangerous for the
strength elements.
In the paper is presented the variation of stress intensity factor of a
steam pipe subjected only to thermal shock.
Keywords: steam pipe, longitudinal cracks, thermal shock
Cuvinte cheie: conductă de abur, fisură longitudinală, şoc termic

96 FACTORUL DE INTENSITATE AL TENSIUNII (KI)


23-71 FACTORUL DE INTENSITATE AL TENSIUNII PENTRU O CONDUCTĂ DE ABUR SUPUSĂ LA ŞOC TERMIC

STRESS INTENSITY FACTOR OF A STEAM PIPE
SUBJECTED UNDER A THERMAL SHOCK
The temperature of a steam pipe is variable because of the steam
pressure variation inside of it. If the steam temperature variation takes place
during a short time, the steam is subjected under a thermal shock. The effect of
the thermal shock is superimposed on the effect of the mechanical load, going
to a load on the pipe. The thermal shocks are dangerous for the strength
elements.
Cuvinte cheie: conductă de abur, tenacitate la rupere, şoc termic
Keywords: steam pipe, stress intensity factor, thermal shock

23-71 FACTORUL DE INTENSITATE AL TENSIUNII PENTRU


21-106 CONSIDERAŢII PRIVIND NECESITATEA ABORDĂRII FENOMENULUI DE OBOSEALĂ LA MAI MULTE SCĂRI. OBOSEALA MESOSCOPICĂ (III)

CONSIDERATIONS REGARDING THE NECESSITY OF
FATIGUE APPROACH ON DIFFERENT SCALES.
FATIGUE MESOSCOPIC (III)
An extensive literature review is presented in this paper, composed of
several parts, regarding the present-day topic of mesoscopic fatigue of
materials. This subject is scarcely represented in the literature from our country.
The authors present a short and accessible approach in order to
familiarize research and production engineers with the new aspects of fatigue
calculation based on the transition from macro to meso scale. Mesoscopic
fatigue takes into account the material’s behavior at the level of crystal grains.
Cuvinte cheie: oboseală, număr cicluri, macroscopic, mesoscopic
Keywords: fatigue, number of cycles, macroscopic, mesoscopic

106 CONSIDERAŢII PRIVIND NECESITATEA ABORDĂRII


21-105 CONSIDERAŢII PRIVIND NECESITATEA ABORDĂRII FENOMENULUI DE OBOSEALĂ LA MAI MULTE SCĂRI. OBOSEALA MESOSCOPICĂ (II)

CONSIDERATIONS REGARDING THE NECESSITY OF
FATIGUE APPROACH ON DIFFERENT SCALES.
FATIGUE MESOSCOPIC (II)
An extensive literature review is presented in this paper, composed of
several parts, regarding the present-day topic of mesoscopic fatigue of
materials. This subject is scarcely represented in the literature from our country.
The authors present a short and accessible approach in order to
familiarize research and production engineers with the new aspects of fatigue
calculation based on the transition from macro to meso scale. Mesoscopic
fatigue takes into account the material’s behavior at the level of crystal grains.
Cuvinte cheie: oboseală, număr cicluri, macroscopic, mesoscopic
Keywords: fatigue, number of cycles, macroscopic, mesoscopic

105 CONSIDERAŢII PRIVIND NECESITATEA ABORDĂRII


21-104 CONSIDERAŢII PRIVIND NECESITATEA ABORDĂRII FENOMENULUI DE OBOSEALĂ LA MAI MULTE SCĂRI. OBOSEALA MESOSCOPICĂ (I)

CONSIDERATIONS REGARDING THE NECESSITY OF
FATIGUE APPROACH ON DIFFERENT SCALES. FATIGUE
MESOSCOPIC (I)
An extensive literature review is presented in this paper, composed of
several parts, regarding the present-day topic of mesoscopic fatigue of
materials. This subject is scarcely represented in the literature from our country.
The authors present a short and accessible approach in order to
familiarize research and production engineers with the new aspects of fatigue
calculation based on the transition from macro to meso scale. Mesoscopic
fatigue takes into account the material’s behavior at the level of crystal grains.
Cuvinte cheie: oboseală, număr cicluri, macroscopic, mesoscopic
Keywords: fatigue, number of cycles, macroscopic, mesoscopic

104 CONSIDERAŢII PRIVIND NECESITATEA ABORDĂRII


21-103 UN ASPECT AL ESTIMĂRII TENACITĂŢII LA RUPERE, δc

AN ASPECT OF ESTIMATING OF THE FRACTURE
TOUGHNESS δc
Between main characteristics, praising the fracture toughness of
materials, there are different relations. The present paper is praising some
difficulties which concerning the fracture toughness, on the basis of a method
which allow to estimate another characteristic, much easy to determine.
Cuvinte cheie: tenacitate la rupere, caracteristici mecanice,
temperatură
Keywords: fracture toughness, mechanical properties, temperature

103 UN ASPECT AL ESTIMĂRII TENACITĂŢII