پديد آورنده :
صالحي، مهدي
عنوان :
توسعه روش هاي عددي و تجربي عيب يابي سازه ها بر اساس مشخصات ارتعاشي آن ها
گرايش تحصيلي :
طراحي كاربردي
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك
صفحه شمار :
پانزده،136ص.: مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
سعيد ضيائي راد، مصطفي غيور
استاد مشاور :
محمد علي وزيري زنجاني
توصيفگر ها :
عيوب سازه اي , تحليل مودال , تابع پاسخ فركانس , تحليل اجزاي اصلي , تحليل اجزاي مستقل
تاريخ نمايه سازي :
19/10/90
استاد داور :
حميد مهديقلي،حميد احمديان،حميدرضا ميردامادي،حسن نحوي
كد ايرانداك :
ID405 دكتري
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Development of Numerical and Experimental Vibration based Methods in Structural Damage Detection Mehdi Salehi Mehdi salehi@me iut ac ir Date of submission October 1 2011 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran S Ziaei Rad1 1st Supervisor szrad@cc iut ac ir M Ghayour2 2nd Supervisor ghayour@cc iut ac ir M A Vaziri Zanjani3 Advisor vaziri@hesaco ir M R Salimpour Department Graduate Program Coordinator Assistant ProfessorAbstract Non Destructive Inspection is one of the old problems in mechanical civil andaerospace engineering Numerous methods such as ultrasound radiography and magneticmethods have been implemented so far All such methods are local methods Besides someknowledge about design loading and service history of the structure should be known apriori In vibration based damage identification no information about the structural design andloading is needed In these methods the damage induced changes of dynamic properties ofthe structure are implemented to detect the damage In this dissertation several novelvibration based damage detection methods are presented In the flexibility based method modal parameters of the intact and damaged structure are extracted and flexibility matricesare formed Flexibility columns in the intact and damaged cases are compared to detect andlocalize the damage Generally structural damage which is accompanied with a local stiffnessreduction causes a curvature discontinuity in the damage site Such sharp points aredetermined via numerical differentiation in all measurement grid points as well as GappedSmoothing method In the next section high dimensional FRF data is reduced to someuncorrelated vectors through K L decomposition These vectors are then used as damageindicative features Data reduction is fulfilled in both time and frequency domains andverified through some numerical and experimental case studies An important advantage of K L reduced vectors over mode shape based methods is that structural time response in eachfrequency can be fully captured by a single reduced vector Moreover the errors due to modalanalysis are eliminated in this method In the next section Independent Component Analysisis implemented to reduce the FRF data The advantage of this technique over K Ldecomposition is that the reduced data are not only uncorrelated but statistically independent In this method output data assumed a linear combination of some unknown independentsources ICA deals with statistical extraction of independent sources as well as mixing matrix The solution is reduced to an optimization scheme maximizing nongaussianity of data ICAapproach is verified through numerical and experimental case studies as well Finally thepresented methods are evaluated and compared Key Words Structural Damage Detection Proper Orthogonal Decomposition IndependentComponent Analysis Frequency Response Function1 Professor2 Associate Professor3 Assistant Professor
استاد راهنما :
سعيد ضيائي راد، مصطفي غيور
استاد مشاور :
محمد علي وزيري زنجاني
استاد داور :
حميد مهديقلي،حميد احمديان،حميدرضا ميردامادي،حسن نحوي
