پديد آورنده :
احمدوند، مريم
عنوان :
معادلات ديناميكي مخازن مستطيلي انعطاف پذير داراي ترك در مجاورت سيال
مقطع تحصيلي :
كارشناسي ارشد
محل تحصيل :
اصفهان : دانشگاه صنعتي اصفهان
صفحه شمار :
پانزده، 201ص.: مصور، جدول، نمودار
استاد مشاور :
مجتبي ازهري
توصيفگر ها :
ورق‌هاي فولادي نازك ترك‌دار , روش ريلي ريتز , مخازن مستطيلي ترك‌دار , اندركنش مايع و مخزن , ارتعاش هيدرواستاتيك , تحليل مودال سازه‌ها
استاد داور :
فرهاد بهنام فر، حسين عموشاهي
تاريخ ورود اطلاعات :
1398/01/21
تاريخ ويرايش اطلاعات :
1398/01/27
چكيده انگليسي :
Dynamic equations of cracked flexible rectangular tanks fully filled with liquid Maryam Ahmadvand m ahmadvand@cv iut ac ir Date of Submission Department of Civil Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Dr Payam Asadi asadi@cc iut ac ir AbstractStructures are always vulnerable to damage during operation Therefore numerous inspections on structures arecarried out to identify the damage done to them Steel storage tanks are one of the most widely used structures forlong life which due to their sensitivity studying their dynamic characteristics is important These tanks are almostexposed to destructive factors such as collisions corrosion and fatigue Creating and propagating the cracks in thesteel tanks reduces their life and causes great damage to the structure The repair of minor damage is low cost andhas fewer problems than global damage and can be implemented without interruption in the operation Hence identification of defects in tanks including cracks is very important before the propagation One of the commondamage identification methods is modal analysis In this way the geometric position and depth of cracks areidentified by the vibration analysis In the present study the dynamic characteristics of flexible fluid tanks were estimated and the effect of crack wasassessed The choice of the appropriate mathematical model of the structure and crack is very important for crackidentifying For this purpose the problem is solved for a simple supporting plate then these equations are expandedfor the rectangular fluid tanks To approximate the displacement of plates by assuming the flexural theory of thinplates polynomial and trigonometric triangular functions are used Using the energy method the energy of thevibrated plate in a perfect and imperfection state due to cracks presence is calculated with respect to the size of thecrack and its depth Using the Rayleigh Ritz method and the matrix of mass and stiffness of the plate for both caseswere extracted The characteristic equation of the tank is formed and the natural frequency changes due to the crackwere estimated The governing equations governing the fluid vibrations were obtained by solving the Laplaceequation and satisfying the boundary conditions of the fluid The results show that natural frequencies decrease with increasing crack size On the other hand changing theposition of the crack changes the natural frequencies To evaluate the accuracy of the used method numerical resultswere compared with the other results of the references One of the innovations in this study is the ability to modelseveral cracks in the plates and the applicability of the proposed theories in the damage identification for flexiblefluid tanks The results show that proposed computational equations provided to estimate the effect of crack on themode shapes For the case studies of possible comparison of results with the other studies displayed that the errorsin calculations in all cases were less than 3 Keywords Cracked Thin Steel plates Rayleigh Ritz Method Cracked Rectangular Tanks Liquid Tank Interaction Hydrostatic Vibration Modal Analysis
استاد مشاور :
مجتبي ازهري
استاد داور :
فرهاد بهنام فر، حسين عموشاهي
