A novel analytical-numerical solution for nonlinear time-dependent electro-thermo-mechanical creep behavior of rotating disk made of piezoelectric polymer

چکیده مقاله

A new analytical-numerical method has been developed for electro-thermo-mechanical transient creep response of rotating disk made of nonlinear piezoelectric polymer. The viscoelastic properties are stress, temperature and time dependent. The disk has been placed in an axisymmetric distributed temperature field and is subjected to a centrifugal body force with free-free, free-fixed and fixed-free boundary conditions. The Burgers’ viscoelastic creep model for long time prediction has been employed. Using the potentialdisplacement equation, charge equation of electrostatics, strain-displacement equations, stress-strain relations and equilibrium equation, the constitutive differential equation in terms of displacement is obtained. The non-homogeneous part of which contains creep strains. An analytical solution for radial displacement in terms of creep strains has been performed. Then the stresses, strains and electric potentials are also derived in terms of creep-strains. Prandtl-Reuss relations and the material creep model are employed to obtain history of displacement, stresses, strains and electric potential. It is concluded that the displacement is increasing with time while effective stresses are decreasing. A significant redistribution occurs for the electric potential which is due to stress redistribution during the lifetime of the disk. The results are validated with ABAQUS software. The analytical-numerical method can be used to predict the history of displacement and stresses in all structures made of nonlinear viscoelastic material