اسماعیل پورسعیدی
استاد، دانشگاه زنجان، دانشکده مهندسی مکانیک، زنجان، ایران
[ 1 ] - تأثیر ترتیب جا زدن و فاصله بین پین‌ها بر توزیع تنش پسماند و رشد ترک لبه‌ای در نمونه‌های تک حفره‌ای
تأثیر ترتیب نصب و فاصله مرکز به مرکز بین پین‌ها بر توزیع تنش‌های پسماند و رشد ترک لبه‌ای، نمونه‌های تک حفره‌ای تحت بارگذاری خستگی بررسی شده است. ترک‌های لبه‌ای حفره‌ای در برخی از قطعات صنعتی همانند پوسته توربین گاز مشاهده می‌شوند. توزیع تنش‌های پسماند ایجاد شده در حفره‌های سه بعدی تحلیل و توزیع دوباره تنش پسماند در حفره‌های هم‌جوار بررسی شده است. تحلیل المان محدود روی نمونه‌های از چدن داکتیل مش...
[ 2 ] - Air Plasma Sprayed Bond Coat Oxidation Behavior and its Resistance to Isothermal and Thermal Shock Loading
An experimental investigation was conducted to find the effect of spraying method of coating of Thermal Barrier Coatings (TBCs) on their oxidation behaviour and resistance to various thermal loading. Isothermal and thermal shock tests were performed in order to study oxidation behaviour of air plasma sprayed Bond Coat (BC) and assess its effect on TBCs lifetime under the stated loadings. Specim...
[ 3 ] - Application of the Hot Spotting Method for the Straightening of a Large Turbine Rotor
Different problems may cause distortion of the rotor, and hence vibration, which is the most severe damage of the turbine rotors. Different techniques have been developed for the straightening of bent rotors. The method for straightening can be selected according to initial information from preliminary inspections and tests such as nondestructive tests, chemical analysis, run out tests and also...
[ 4 ] - Comparison of Properties of Ti/TiN/TiCN/TiAlN Film Deposited by Cathodic Arc Physical Vapor and Plasma-assisted Chemical Vapor Deposition on Custom 450 Steel Substrates
This study investigated the effects of deposition techniques on the microstructural and tribological properties of Ti/TiN/TiCN/TiAlN multilayer coatings onto a Custom 450 steel substrate. The coatings were produced using cathodic arc physical vapor deposition (CAPVD) and plasma-assisted chemical vapor deposition (PACVD). The microstructural of the coatings was evaluated using (SEM), and phase f...
[ 5 ] - Reverse Engineering for Designing the Coupling of a 32 MW Rotor-generator by Shrink Fitting Method (TECHNICAL NOTE)
This study presents a designing process for refurbishing of a 32 MW rotor-generator damaged coupling. The reason of rotor damage was being hit by the quivers of an explosion. The original coupling was union with the rotor formed after a machining process on a mono block forged rotor. In some areas imposed damages caused the breaking off and detachment of some parts in the coupling flange. Becau...
[ 6 ] - An Outrun Competition of Corrosion Fatigue and Stress Corrosion Cracking on Crack Initiation in a Compressor Blade
First row rotating blades of four axial-flow compressors were prematurely fractured. Previous investigations showed that the site atmosphere contains corrosive compounds which lead to an increase in possibility of pitting on the blades. It was also revealed that the crack was originated from two corrosion pits. Thus, this work is conducted to ascertain which of fatigue or stress corrosion crack...
[ 7 ] - Failure Probability and Remaining Life Assessment of Reheater Tubes
In this study, a real and significant industrial problem in a steam power plant was investigated. Reheater tubes in boilers are under the creep and the fireside corrosion mechanism that cause some of them to fail. Since the estimation of probability of failure (PoF) and remaining life (RL) is expensive and time consuming in the deterministic methods, in this work they were evaluated using struc...
[ 8 ] - Life Estimate of a Compressor Blade through Fractography
Failure analysis of fractured components provides some information about the causes and conditions of fracture. Fractography is an indispensable part of the failure analysis as it is usually the only means by which the failure mechanism can be established. By using fractography, some information such as component’s life, values of the stress intensity factor and the applied stress can be calcul...
[ 9 ] - The Causes of Local Hardness Increasing in Powerplant Rotors and its Modification by Tempering (TECHNICAL NOTE)
Local hardness increasing on the surface of the power plant rotor may result in severe damages. One major solution for rapid repairing of the rotors is the adaptive tempering heat treatment. For this purpose, after identification of the damaged rotor, initial investigations and tests (such as visual inspection, chemical analysis, nondestructive hardness measurements and replica or on-site metal...
[ 10 ] - An Investigation on the Causes of a Rotor Bending and its Thermal Straightening (TECHNICAL NOTE)
Distortion or bend in a turbine rotor (especially HIP rotors) may be caused by a number of factors, either singularly or in combination. In general, the causes of rotor bend can be classified invariably in two categories: Rapidly forming permanent rotor bends and/or Slower forming rotor bends, which could trip the turbines’ emergency stop. One of the major modifying solutions for rapid repairin...
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