10153

9371

كارشناسي ارشد

طراحي كاربردي

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مكانيك

1393

چهارده، 107ص.: مصور، جدول، نمودار

ص.ع. به فارسي و انگليسي

مصطفي غيور

حميدرضا ميردامادي

9/3/94

عليرضا شهيدي، مهدي كاروان

1396/10/02

كتابنامه

مكانيك

مهندسي مكانيك

ID9371

Vibration Analysis of Rotating Truncated Conical Shells with Functionally Graded Properties Mohammadreza Farnam m farnam@me iut ac ir Date of Submission 2015 01 17 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Mostafa Ghayour ghayour@cc iut ac irAbstract Conical shells are of the most widely engineering structures and various studies have been conducted inthe analysis of their behavior They are widely used in generous engineering applications such as hoppers vessel heads components of missiles spacecraft and marine vessels Vibration analysis is one of the mostimportant issues in the field Nowadays in order to improve the behavior and properties of the shells functionally graded materials FGM are used in their manufactures Mechanical properties of them as non homogeneous materials are changed continuously Usually these materials are made from ceramic andmetal The ceramic constituent of the material provides the high temperature resistance due to its low thermalconductivity The ductile metal constituent prevents fracture caused by stresses due to high temperaturegradient In this research free vibration of rotating functionally graded truncated conical shells is investigated Vibration analysis is based on shell thickness using the theories of two dimensional and three dimensionalfor shells For thin walled moderately thick and thick conical shells are used the classical first order sheardeformation and layerwise theory respectively In classical shell theory it is assumed that transverse normaland shear strains are zero Transverse shear strain and rotary inertia effects are considered in first order sheardeformation shell theory In contrast to the equivalent single layer theories ESL the layerwise theorydevelops the separate displacement field expansions through the each subdivision The displacementcomponents are continuous through the thickness but their derivatives with respect to the thicknesscoordinate may be discontinuous at boundary layers through the thickness The initial equilibrium equationsand the free vibration equations of motion around this equilibrium state are derived applying the Newton Euler and Hamilton s principle using energy functions method Using the GDQ method the partialdifferential equations are transformed in to the linear algebraic equations natural frequencies and modeshapes are obtained by using eigenvalue equation by considering boundary conditions Results show convergence of this method and compared with other published works By severalnumerical solutions the effects of material property graded index angular velocity Coriolis acceleration geometrical parameters and boundary conditions on the natural frequency are investigated Also the criticalvelocity in unstable condition is obtained At the end the results of these noted theories compared with eachother For thin walled conical shells each theory has sufficiently accurate But in thick conical shells thedifference of natural frequency between classical and first order shear deformation theory is significant Keywords Free vibration Conical shells Functionally Graded Materials GDQ Classical First order shear deformation Layerwise theory

مصطفي غيور

حميدرضا ميردامادي

عليرضا شهيدي، مهدي كاروان