An Axisymmetric Electrothermoviscoelastic Problem for a Partially Depolarized Piezoceramic Sphere Under Quasistatic Harmonic Loading

The analytical solution is obtained for the vibrations and dissipative heating of a hollow piezoceramic sphere polarized across the thickness, with thermal depolarization taken into account. The sphere is subjected to a quasistatic potential difference varying harmonically with time. The inside surface is heat-insulated and the outside surface is involved in convective heat exchange with the environment. A numerical analysis is made and the depolarization conditions and the effect of the depolarized region on the stress–strain state and heating temperature are analyzed.     

Flexural Vibrations and Heating of a Circular Bimorph Piezoplate under Electric Excitation Applied to Nonuniformly Electroded Surfaces

The flexural vibrations and dissipative heating of a circular bimorph piezoceramic plate are studied. The plate is excited by a harmonic electric field applied to nonuniformly electroded surfaces. The viscoelastic behavior of piezoceramics is described in terms of temperature-dependent complex moduli. The nonlinear coupled problem of thermoviscoelasticity is solved by step-by-step integration in time, using the discrete-orthogonalization method to solve the mechanics equations and the finite-differences method to solve the heat-conduction equations. A numerical analysis is conducted for TsTStBS-2 piezoceramics to study the influence of the nonuniform electroding on the resonant frequency, amplitude, and modes of flexural vibrations and the amplitude- and temperature-frequency characteristics of the plate __________ Translated from Prikladnaya Mekhanika, Vol. 41, No. 9, pp. 94–100, September 2005.     

Forced Vibration and Self-Heating of a Thermoviscoelastic Cylindrical Shear Compliant Shell with Piezoelectric Actuators and Sensors*

International Applied Mechanics - The problem of the forced resonant vibrations and dissipative heating of a hinged thermoviscoelastic cylindrical shell with piezoelectric actuators and sensors is...     

Resonant Vibrations and Dissipative Heating of an Infinite Piezoceramic Cylinder

The monoharmonic radial vibrations and dissipative heating of an infinite hollow piezoceramic cylinder are studied in dynamic formulation, taking into account the temperature dependence of the complex electromechanical characteristics over a wide range of temperatures, including depolarization temperatures. The influence of the heat exchange conditions, the level of electric load, and geometry on the thermoelectromechanical characteristics is studied in the case of forced vibrations at the first resonance__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 3, pp. 101–107, March 2005.     

Vibrations and Dissipative Heating of a Viscoelastic Beam under a Moving Load

The vibrations and dissipative heating of an infinite viscoelastic beam under a moving load are studied on the basis of Timoshenko beam theory. The influence of transverse-shear strain and rotary inertia on the critical velocities of the moving load, the amplitude of bending vibration, and the temperature of dissipative heating is analyzed__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 1, pp. 69–76, January 2005.     

X-ray spectral and Mossbauer investigations of structure defects and the degree of inversion of manganese-zinc ferrites

X-ray and Mossbauer spectroscopy is used to investigate the effect of vacuum cooling on the valence of cations of manganese and iron, nonstoichiometry and the degree of inversion of manganese-zinc ferrites. The dependence of the valency of the cations of manganese and iron, the degree of inversion, and the degree of nonstoichiometry on the partial pressure of oxygen produced in the cooling stage is established. An interrelationship is found between the defects and the degree of inversion of manganese-zinc ferrites.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 3, pp. 15–18, March, 1982.