نتایج جستجو برای: mechanical fatigue

تعداد نتایج: 302965  

پایان نامه :دانشگاه آزاد اسلامی واحد علوم پزشکی تهران - دانشکده پزشکی 1389

سابقه هدف: msیکی از شایعترین اختلالات نورولوژیک ناتوان کننده است که با تریاد التهاب ، demyelination ، وگلیوزیس نورونها مشخص می شود . بیش از 2.5 میلیون نفر در جهان به این بیماری مبتلا هستند و بیشترین شیوع آن در بالغین جوان است . یکی از شایعترین علایم ms ، خستگی می باشد که حدود 90 % بیماران به آن دچارند. با وجودیکه fatigue ، شایعترین علت ناتوانی بیماران ms می باشد ، هنوز پزشکان در تشخیص و درمان آ...

Journal: :مهندسی متالورژی و مواد 0
حمید خرسند حسن عبدوس مصطفی امیرجان

in the present study, the mechanical properties and fracture mechanisms of two powder metallurgy low alloy steels, i.e. distaloy dh and distaloy hp, were investigated. all samples were sintered at 1120 ºc for 30 min in n2/h2 atmosphere. for evaluation of the effect of cooling rate on final properties, samples were cooled from sintering temperature with two different cooling rates. in addition, ...

2008
Soon-Bok Lee Ilho Kim

Modern electronics products move in the direction of complex, high density, high speed and also thinner and lighter for portability. Reliability of interconnection of electronics packaging has become critical issue. Major functions of electronic packaging are briefly discussed and failure mechanisms of electronic packaging are explained. Electronics packaging is subjected to mechanical vibratio...

2017
Li Hao Li Rui-Xin Han Biao Zhao Bin Hao Bao-Hui Liu Ying-Jie Zhang Xi-Zheng

BACKGROUND Fatigue damage of the long bones is prevalent in running athletes and military recruits due to vigorous mid- and long-term physical activity. The current study attempted to know the features of bony athletic fatigue damage and to explore the mechanism of fatigue damage repair through bone targeted remodeling process. METHODS Right ulnae of the Wistar rats were fatigue loaded on an ...

2005
Tae-Sang Park Soon-Bok Lee

To give a proper and accurate estimation of the fatigue life of ball grid array (BGA) solder joints, a mechanical fatigue test method under mixed-mode loading is proposed. Experiments were conducted with 63Sn/37Pb and Sn/3.5Ag/0.75Cu solder joints in room temperature. The mechanical low cycle fatigue tests were performed under several loading angles. The loading angle is controlled by several g...

Journal: :international journal of advanced design and manufacturing technology 0
ahmed khalid hussain kanukati vinay kumar mohd zubair nizami syed yousufuddin

abstract – aluminium 7075- t651 alloys are widely used in the production of light weight structures requiring a high strength to weight ratio and high corrosion resistance. the effect of processing parameters on fatigue life of 7075- t651 aluminium joints produced by friction stir welding was investigated in the present study. welding samples were made by employing rotating tool speed of 770, 9...

Journal: :journal of computational and applied research in mechanial engineering - jcarme 0
m. jooybari school of mechanical engineering, college of engineering, university of tehran, tehran, iran j. shahbazi karami faculty of mechanical engineering, shahid rajaee teacher training university, tehran, iran m. sheikhi faculty of mechanical engineering, shahid rajaee teacher training university, tehran, iran

in the present study, mechanical properties and low cycle fatigue behavior of a solid-solutionized aa6061 aluminum alloy produced by equal channel angular pressing (ecap) process were investigated. the grain refinement after two passes of ecap significantly increased the yield stress and ultimate tensile stress and decreased the ductility of the alloy. however, the improvement of low cycle fati...

Since martensitic precipitation hardened 17-4pH stainless steel has been widely used in corrosive environments, evaluation of its corrosion fatigue behavior is important. In this research, after microstructural studies, mechanical, corrosion, fatigue and corrosion fatigue tests were performed on 17-4pH specimens. Fatigue and corrosion fatigue tests were carried out at the  stress ratio of -1 an...

ژورنال: تحقیقات موتور 2018
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In this article, the thermo-mechanical fatigue lifetime of the cylinder head of a passenger-car diesel engine has been estimated. At the first stage, stress and strain distributions in the cylinder head have been calculated using the two-layer visco-plastic model, available in the ABAQUS software. The calibration of the model was performed, using correlating of simulated hysteresis curves and l...

Excellent mechanical properties and fatigue performance of Al/Al2O3 metal-based nanocomposites caused to introduce this material as a good candidate for various applications. In this regard, the preparation and characterization of this composite can be considered as a hot issue for research. The study was carried out in several steps including: (i) preparation of Al/Al2O3 metal-based nanocompos...

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