The forced transversal vibrations and vibroheating of a cylindrical bimorph panel made from a dissipative piezomaterial

The forced vibrations and dissipative heating of a bimorph cylindrical shell are considered. The shell is made from a dissipative piezomaterial and subjected to a harmonic potential difference. The edges of the panel are assumed hinged and perfectly heat-insulated. The dissipative properties of the material are considered on the basis of the concept of complex characteristics. The analystical solution of this problem is found. A finite-element method is developed to study the dynamic behavior and vibroheating temperature of bimorph shells, which are made from viscoelastic material and subjected to harmonic loading. The results of the analyses of the electromechanical vibrations of the panel performed by the finite-element method and by analytically solving the problem are compared. Translated from Prikladnaya Mekhanika, Vol. 36, No. 5, pp. 89–97, Mary, 2000     

Influence of boundary conditions and temperature of dissipative heating on active damping of forced axisymmetric resonant bending vibrations of circular viscoelastic plates by piezoelectric sensors and actuators

The problem of forced monoharmonic, axisymmetric, bending vibrations and dissipative heating of circular viscoelastic plates with piezoelectric sensors and actuators is considered. We describe the viscoelastic behavior of a passive (without the piezoeffect) and a piezoactive material according to the concept of complex modules depending on temperature. The nonlinear coupled problem of electrothermoviscoelasticity is solved by numerical methods. The influence of boundary conditions and temperature of dissipative heating on the active damping of forced resonant vibrations of circular viscoelastic plates using piezoelectric sensors and actuators is investigated.     

Products of the Reactions of 1-Aroyl-2,2-dimethylhydrazines with Propargyl and Allyl Bromides

1-Aroyl-2,2-dimethylhydrazines react with propargyl and allyl bromides to form, respectively, 1,1-dimethyl-1-(2-propyn-1-yl)- and 1,1-dimethyl-1-(2-propen-1-yl)-2-aroylhydrazinium bromides. Treatment of these compounds with an NaOH solution yielded, respectively, N-[dimethyl(2-propyn-1-yl)ammonio]- and N-[dimethyl(2-propen-1-yl)ammonio]aroylimides.     

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.     

Damping the resonant flexural vibration of a hinged plate with actuators

The paper addresses the active damping of the resonant flexural vibration of a hinged viscoelastic rectangular plate with distributed piezoelectric actuators. The thermomechanical behavior of passive and active materials is described using the concept of complex characteristics. The interaction of the mechanical and temperature fields is taken into account. To solve the problem, the variational and Bubnov–Galerkin methods are used. The effect of the temperature of dissipative heating on the effectiveness of the active damping of resonant vibration is studied     

Reaction of Thiosemicarbazones from Heterocyclic Series with Acetic Anhydride

Russian Journal of Organic Chemistry -     

Reactions of 1-[Benzoyl(2-hetaroyl)]-2,2-dimethyhydrazines with 1,3-Dibromopropyne, 2-Propynyl Bromide,and Allyl Bromide

Reactions of 1-[benzoyl(2-hetaroyl)]-2,2-dimethyhydrazines with 1,3-dibromopropyne in MeOH at 50°C afforded 2-phenyl(heteryl)-6-bromomethylidene-4,4-dimethyl-5H-1,3,4-oxadiazinium bromides. Reactions of 1-[benzoyl(2-hetaroyl)]-2,2-dimethyhydrazines with propargyl bromide and allyl bromide gave rise to 1,1-dimethyl-1-(2-propyn-1-yl)- and 1,1-dimethyl-1-(2-propen-1-yl)-2-benzoyl(hetaroyl)hydrazinium bromides. On treating these compounds with NaOH solution the corresponding imides were obtained.     

Forced axisymmetric vibrations and self-heating of a circular viscoelastic plate,controlled with piezoelectric sensors and actuators

The forced monoharmonic vibrations and self-heating of a circular thermoviscoelastic plate with piezoelectric sensor and actuator are studied. The viscoelastic behavior of the passive (without piezoeffect) and piezoactive materials is described using the concept of complex moduli. The problems of electroelasticity and heat conduction are solved numerically, assuming that the mechanical load is unknown. The effect of self-heating on the active damping of the vibrations of the plate is analyzed     

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.