آناليز غير خطي كمانش يك طرفه ورق مركب لايه لايه پيزوالكتريك بر روي بيشتر الاستيك بدون كشش برانگيخته شده با نيروهاي الكتريكي، مكانيكي و گرمايي

چكيده انگليسي :

Unilateral Buckling Nonlinear Analysis of Piezoelectric Laminated Composite Plate on Elastic Tensionless Foundation Excited by Electrical Mechanical and Thermal loads Omid Vaseghi o vaseghi@me iut ac ir Date of Submission 2011 05 8 Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language FarsiSupervisor Hamid Reza Mirdamadi hrmirdamadi@cc iut ac ir Ali Reza Shahidi shahidi@cc iut ac irAbstract Plates as one of the most commonly used structural elements of mechanical systems and load bearingstructures are the most important structural parts and have the widest utility in structural mechanical andaerospace engineering for building flexible structures such as aircraft spacecraft and marine structures Froma mechanical point of view when a plate is subjected to compressive in plane loads and tends to go out of theloaded plane the buckling phenomenon has occurred The buckling which occurs as a result of compressive in plane loads structural defects eccentric loads etc leads to structural instability and damage to structures In thisthesis nonlinear unilateral buckling analysis of laminated composite plates with sensor and actuator piezoelectriclayers has been studied The plate is placed on a unilateral elastic foundation is not able to apply tension load This is due to unilateral constraint and loads to a nonlinear buckling problem The unilateral buckling of platesis in fact a contact problem The stability analysis of plates resting on foundations e g concrete beam column reinforced plates etc are some of its practical usages Different kinds of in plane loads are induced in the platebecause of mechanical electrical and thermal loads or a combination For the analysis of this behavior bothRayleigh Ritz and finite element methods are used based on classical plate theory Kirchhoff theory In finiteelement method a rectangular 4 node conforming element scheme with 16 DOF element using Hermiteinterpolation functions for out of plane behavior and 8 DOF elements using Lagrange interpolation functions for in plane behavior are used In Rayleigh Ritz method Khayyam Pascal polynomial for out of planebehavior and hierarchical interpolation functions for in plane behavior are implemented Finally the effects ofYoung s modulus ratio fiber orientation plate aspect ratio different boundary conditions in plane out ofplane the number and arrangements of layers angle ply cross ply the presence of sensor and actuatorpiezoelectric layers electrical conditions open circuit closed circuit and the magnitude of control gain arestudied severity of the loads temperature and critical bilateral and unilateral buckling voltages respectively excited by mechanical thermal and electrical loads or a combination All previous researches on the unilateralbuckling of plates are limited to single layer isotropic plates The simulated results are compared with previousworks which have studied the unilateral buckling of single layer isotropic plates resting on elastic foundation free of interaction with any foundation buckling of both symmetric and unsymmetric laminated compositeplates excited by mechanical thermal and electrical loads or a combination The numerical results are validatedsatisfactorily for both numerical methods and their accuracy and reliability have been confirmed Keywords Unilateral buckling Rayleigh Ritz methods Finite element methods Kirchhofftheory Sensor and actuator piezoelectric Thermo electro mechanical loading

واثقي، اميد

آناليز غير خطي كمانش يك طرفه ورق مركب لايه لايه پيزوالكتريك بر روي بيشتر الاستيك بدون كشش برانگيخته شده با نيروهاي الكتريكي، مكانيكي و گرمايي

روش ريلي - ريتز , روش اجزاي محدود , تئوري كلاسيك , حسگر بكار اندازنده پيزوالكتريك