پديد آورنده :
جعفري وردنجاني، مهدي
عنوان :
تحليل حذف تنشهاي پسماند ايجاد شده توسط فرآيندهاي ماشينكاري به كمك روشهاي ارتعاشي
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك
صفحه شمار :
نه، 83ص.: مصور، جدول، نمودار
يادداشت :
ص.ع. به فارسي و انگليسي
استاد راهنما :
مصطفي غيور
استاد مشاور :
محمدرضا فروزان
توصيفگر ها :
تنش زدائي ارتعاشي , تنش پسماند , جوشكاري
تاريخ نمايه سازي :
9/2/91
استاد داور :
محسن صفوي، محمد مشايخي
تاريخ ورود اطلاعات :
1396/10/12
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Analysis of vibrational stress relief method for residual stresses caused by machining processes Mehdi Jafari Rester sabt@hotmail com September 2011 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Mostafa Ghayour Email ghayour@cc iut ac irAbstractPrincipally after any manufacturing process there will be some residual stress remained inthe products having its own stress distribution based on the characteristics of manufacturingprocess To obtain the desired accuracy and quality of the product we need to relieve a largeamount of residual stress Among stress relief processes used these days are heat treatmentand vibrational treatment As far as the basic of stress relief process is concerned they aresimilar to each other since both make the part relieve some stress by imposing some plasticdeformation in the part The principle of this phenomenon is that the stresses made by loadsgenerated by heat or vibration is summed with the residual stresses and it exceeds the stressyield stress The main purpose of this project is to investigate the main factors affecting thevibrational stress relief process including amplitude or load loading frequency and numberof cycles The main plan of this project implies that the part having residual stress undergoesa vibrational stress relief process then the mentioned factors are considered to check howmuch they can reduce the measure of residual stress in the part Analysis and investigation of this problem is performed on a cantilever beam This project isdone on three different phases including theoretical analysis simulation and experimentalwork In theoretical phase a bending moment induces the residual stresses in the beam Thena reverse bending moment applies the first cycle of our alternative loading In this way wecan investigate the effect of different parameters of vibrational loading and check howefficient each one is To do this the results of numerical analysis is obtained and the amountof relieved stress after applying the first cycle of vibrational loading for a cantilever beammade from the desired material is obtained via derived equations For simulation part vibratory stress relieving parameters are investigated again for a cantilever beam Theparameters comprise two factors having four levels plus a one level factor In overall 48simulated tests were evaluated and the optimized levels of factors are obtained The results ofsimulation phase are then compared with the results of an experimental test done on acantilever beam which is first machined and then vibrated The comparison is done usinghardness property and elastic modulus obtained via the nano indentor device The results imply an important point about the main parameters and it s about the analogousness ofoptimized ranges for parameters in all three phases In other word the good area for theparameter frequency is less than resonant frequency while the time period doesn t need not tobe in higher levels These ranges for these parameters plus the medium level of loadingusually yield in acceptable results Key Words Vibrational stress relief Residual Stress Plastic limit
استاد راهنما :
مصطفي غيور
استاد مشاور :
محمدرضا فروزان
استاد داور :
محسن صفوي، محمد مشايخي
