| 000 | 07810nam a2200433 4500 | ||
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| 003 | EG-NbEJU | ||
| 005 | 20241204202457.0 | ||
| 008 | 240924b2024 ua | m||| 00| 0 eng d | ||
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_aEG-NbEJU _beng _cEG-NbEJU _dEG-NbEJU |
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| 041 |
_aeng _bara |
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_aIME PhD. 2024 _b02 |
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| 100 | 1 | _aMahmoud , Mahmoud Mohammed Atef Abdalhamed | |
| 245 | 1 | 0 |
_aDynamic Modeling and Simulation of Defected Rolling Element Bearings Working under Different Operating Conditions : _bA Thesis Submitted to the Graduate School of Innovative Design Engineering : Egypt - Japan University of Science and Technology (E - JUST) : In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Industrial and Manufacturing Engineering / _cby Mahmoud Mohammed Atef Abdalhamed Mahmoud ; Supervisor Committee Associate prof. Mohamed Galal Nassef - Industrial and Manufacturing Engineering - E-JUST - Egypt , Associate prof. Wael Mahmoud Khaireldien - Industrial and Manufacturing Engineering - E-JUST - Egypt , Prof. Jiwang Yan - Mechanical Engineering - Keio University - Japan ; Examination Committee Prof. Amal Elhosaieny Meselhy Alshorbagy - Mechanical Design and Production Engineering - Zagazig University - Egypt , Prof. Ossama Moustafa Mohamed Mokhiamar - Mechanical Engineering - Alexandria University - Egypt , Associate prof. Mohamed Galal Nassef - Industrial and Manufacturing Engineering - E-JUST - Egypt , Associate prof. Wael Mahmoud Khaireldien - Industrial and Manufacturing Engineering - E-JUST - Egypt |
| 246 | 1 | 5 |
_aالنمذجة و المحاكاة الديناميكية لكراسي التحميل المعيبة ذات العناصر المتدحرجة في ظروف تشغيل مختلفة : _bرسالة علمية مقدمة الى المدرسة التخصصية للدرسات العليا - هندسة التصميم الإبداعي - الجامعة المصرية اليابانية للعلوم و التكنولوجيا كاستيفاء جزئي لمتطلبات الحصول على درجة دكتوراه الفلسفة في الهندسة الصناعية و التصنيع / إعداد محمود محمد عاطف عبدالحميد محمود ; لجنة الاشراف على الرسالة أ.م.د. محمد جلال ناصف - قسم الهندسة الصناعية و التصنيع - الجامعة المصرية اليابانية للعلوم و التكنولوجيا , أ.م.د. وائل محمود خير الدين - قسم الهندسة الصناعية و التصنيع - الجامعة المصرية اليابانية للعلوم و التكنولوجيا , أ.د. جيوانغ يان - قسم الهندسة الميكانيكية - جامعة كيو- اليابان ; لجنة المناقشة و الحكم على الرسالة أ.د امل الحسيني مصلحي الشوربجي - قسم التصميم الميكانيكي والأنتاج، جامعة الزقازيق , أ.د. اسامه مصطفى محمد مخيمر - قسم الهندسة الميكانيكية - جامعة الأسكندرية , أ.م.د. محمد جلال ناصف - قسم الهندسة الصناعية و التصنيع - الجامعة المصرية اليابانية للعلوم و التكنولوجيا , أ.م.د. وائل محمود خير الدين - قسم الهندسة الصناعية و التصنيع - الجامعة المصرية اليابانية للعلوم و التكنولوجيا |
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_aAlexandria : _bMahmoud Mohammed Atef Abdalhamed Mahmoud _c2024 |
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_a106 leaves ; _c30 cm |
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| 500 | _aIncludes a title page in Arabic | ||
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_aThesis (Ph.D.) _bDoctoral _cEgypt - Japan University of Science and Technology (E - JUST) - School of Innovative Design Engineering - Industrial and Manufacturing Engineering Department _d2024 |
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| 520 | _a.Rolling element bearings (REBS) are essential components in rotating machinery , providing support and minimizing friction between moving and stationary parts Despite their widespread use , REBs are susceptible to failure due to localized defects and skidding damage , which can significantly reduce their lifespan and performance Rolling contact fatigue, electric erosion, and plastic deformation lead to the formation of localized defects on REB surfaces , such as spalls, dents, or bumps These defects increase vibration levels and compromise machinery reliability , potentially leading to severe damage or catastrophic failures if undetected early Moreover , skidding damage is considered one of the leading causes of wear mechanisms in REBS , and it accelerates the presence of localized defects. Despite extensive research on the investigation of REB dynamic behavior , the combined effect of different defect types on bearing vibrations has been relatively understudied Also , only a few REBS dynamic models considered cage flexibility , and a little effort was focused on the effect of lubricant types on the REB Skidding behavior In this study, a 6-DOF dynamic model is developed to investigate the vibration characteristics of REB with a multipoint defect comprising a dent and bump on its raceway surface The model considers various factors such as time-varying contact forces due to defects , lubricant film damping , bearing preload , and the inertia effect of rolling elements Additionally , the impact of lubricant characteristics on REB skidding is explored at different speed states using an improved nonlinear skidding dynamic model The model incorporates time-varying traction coefficient , cage flexibility , and cage pocket clearance The tested lubricants are lithium grease (LGT2), compound calcium sulfonate (CCS) grease , and 4109 Chinese aviation oil The simulation results indicate that vibration patterns are significantly affected by defect type , size , and angle between defects In addition , it highlights the challenge of predicting bearing defect parameters solely from acceleration signal analysis , emphasizing the need for jerk signal analysis Furthermore , simulation results indicate that lubricant properties significantly affect REB dynamic performance , influencing cage slip ratio , roller - raceway sliding velocity , and cage-roller impact force Notably , CCS grease exhibits superior efficiency across all operating conditions , attributed to its structural strength , shear stability , and high oil release rate This study provides valuable insights for enhancing the stability , reliability , and safety of rotating machinery by facilitating early fault detection and diagnosis of REBs Additionally , it underscores the importance of selecting appropriate lubricants tailored to specific operating conditions | ||
| 530 | _aIssued also as a digital file (for more information please check our Digital Repository) | ||
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_aIDE _bIME |
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| 700 | 1 |
_aNassef , Mohamed Galal _eSupervisor |
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| 700 | 1 |
_aKhaireldien , Mahmoud _eco-Supervisor |
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| 700 | 1 |
_aYan , Jiwang _eco-Supervisor |
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| 700 | 1 |
_aAlshorbagy , Amal Elhosaieny Meselhy _eExaminator |
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| 700 | 1 |
_aMokhiamar , Ossama Moustafa Mohamed _eco-Examinator |
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| 700 | 1 |
_aNassef , Mohamed Galal _eco-Examinator |
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| 700 | 1 |
_aKhaireldien , Wael Mahmoud _eco-Examinator |
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| 700 | 1 |
_aناصف , محمد جلال _eمشرف |
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| 700 | 1 |
_aخير الدين , وائل محمود _eمشرف مساعد |
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| 700 | 1 |
_aيان , جيوانغ _eمشرف مساعد |
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| 700 | 1 |
_aالشوربجي , امل الحسيني مصلحي _eمناقش |
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| 700 | 1 |
_aاسامه مصطفى محمد مخيمر _eمناقش مساعد |
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| 700 | 1 |
_aناصف , محمد جلال _eمناقش مساعد |
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| 700 | 1 |
_aخير الدين , وائل محمود _eمناقش مساعد |
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| 901 | _aHaGeR | ||
| 902 | _aTh-New_ (1).pdf | ||
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_2lcc _n0 _cDISS |
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_c6855 _d6855 |
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