پديد آورنده :
شفيع، بنيامين
عنوان :
تحليل ديناميكي تير روي بستر غيريكنواخت و غيرخطي تحت تأثير عبور نوسان‌گر
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
طراحي كاربردي
محل تحصيل :
اصفهان : دانشگاه صنعتي اصفهان
صفحه شمار :
پانزده، 114ص. مصور، جدول، نمودار
توصيفگر ها :
بستر غيرخطي , بستر دوخطي , نوسان‌گر عبوري , بستر غيريكنواخت , سرعت بحراني
استاد داور :
سعيد ضيايي راد، رضا تيكني
تاريخ ورود اطلاعات :
1399/08/12
رشته تحصيلي :
مهندسي مكانيك
تاريخ ويرايش اطلاعات :
1399/08/12
چكيده انگليسي :
Dynamic Analysis of a Beam on Non Uniform Nonlinear Foundation Subjected to a Moving Oscillator Benyamin Shafi b shafi@me iut ac ir September 15 2020 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 IranDegree Master of Science Language FarsiSupervisor Hassan Nahvi Prof hnahvi@iut ac ir AbstractInvestigating the dynamic response of a beam on elastic foundation subjected to a moving mass is an im portant issue in mechanical and structural engineering analysis Analysis of high speed train movement ona track placed on a foundation is one of the important applications of this problem Due to the importanceof this issue in addition to the dynamic response of the beam the dynamic analysis of the moving mass isalso of particular importance In addition in this case foundation modeling has significant effect on obtain ing critical velocities and also beam and mass maximum displacements Therefore in this study the movingmass is modeled by mass spring damper oscillators as a single degree of freedom and one foot and two foottwo degree of freedom cases Furthermore foundation modeling will be considered as linear nonlinear andbi linear Winkler cases Also for sudden changes of foundation stiffness the non uniform foundation will beconsidered and compared with the uniform foundation In all cases critical velocities and extreme values ofbeam and moving oscillator displacements will be obtained using finite element method and numerically com puted using method The effects of stiffness of different foundation cases and natural frequencies of movingoscillator on the time response of beam and moving oscillators will be investigated In linear and non uniformfoundation model the critical velocities were reduced compared to the linear and uniform model when movingfrom the foundation with lower stiffness to the foundation with higher stiffness In nonlinear model comparedto the linear one the extreme displacement values decreased and the critical velocities increased Also in thismodel by increasing the natural frequency the number of direction changes of the oscillator displacementsincreased By considering non uniform foundation less extreme displacements and higher critical velocitiesoccurred when oscillator moves from the region of lower foundation stiffness to the higher one By consideringfoundation with less tensile stiffness in the bi linear model the oscillator upward displacements increased andthe critical velocities decreased In bi inear model unlike the other models using two degree of freedom os cillator increased the extreme displacement when crossing from the lower stiffness region to the more stiffnessone In all the considered models the highest oscillator and beam displacements occurred during the presenceof the oscillator at the end of the beam KeywordsNonlinear Foundation Bi linear Foundation Moving Oscillator Non uniform Foundation Critical Velocity
استاد داور :
سعيد ضيايي راد، رضا تيكني
