چكيده به لاتين
Abstract:
In many applications of structures, man has been able to pursue major goals by applying new effects to different structures. As an example, the researchers have been able to obtain piezoelectric properties and by applying electrical input, create special and arbitrary mechanical deformations, and even vice versa, with the use of certain mechanical forces, they can have electrical voltage. In spatial structures, in addition to Such effects include other effects such as electromagnetic fields, thermal fields, radiation fields, and so on that are significant. This is while the major designs that have been made in the field of space structures have been made using simple theories without considering the said field effects. For this purpose, in this thesis, the effect of coupling or field dependence on structural vibrations has been investigated. In this dissertation, the nanoplate piezoelectric and nanoplate electromagnetic are analyzed with the Mindelin theory and Eringen's nonlocal theory for different boundary conditions. The equations are derivation from the Hamilton principle and are Discreted in a generalized differential quadrature method (GDQM) and solved by the EigenValue problem, also external effect on spatial structure vibrations are also investigated. In this study, the results indicate that increasing the nonlocal coefficient, increasing the voltage,temperature change and magnetic load led to slake frequency. Different simulations have been carried out that confirms GDQM with few number of points led to accuracy and convergence, and The more number of discrete points,led to the more precision will be. Also, an aluminum nitride under a voltage of 1 kV is led to oscillating stress at 10 GPA, which is more higher than theyield stress of 2700 MPa.
Keywords: Space, Vibrations, Piezoelectric, Field Coupling, Mindelin Theory, GDQ Method.
