Forced vibrations and vibroheating of shallow viscoelastic laminated shells with the piezoelectric effect

The vibrations and dissipative heating of a hinged shallow shell made of viscoelastic piezoelectric material and subject to harmonic electric loading are considered. The basic relations are obtained by using the Kirchhoff-Love mechanical hypotheses supplemented with the respective hypotheses for electric quantities. Analytical solutions of both electromechanical and thermal problems are derived for the case where the temperature is constant along the shell thickness. Translated from Prikladnaya Mekhanika, Vol. 36, No. 6, pp. 78–87, June, 2000.     

Synthesis of 3-acylmethyl-1,5-dihydrobenzo[e]-2,4-dithiepins and 1,2-di(acylvinylthiomethyl)-4,5-dimethylbenzenes from α-acetylene ketones

Substituted 1,5-dihydrobenzo[e]-2,4-dithiepins and 1,2-di(acylvinylthiomethyl)-4,5-dimethylbenzenes were synthesized by the reaction between -acetylene ketones and 1,2-dimethyl-4,5-di(mercaptomethyl)benzene in chloroform in the presence of K₂CO₃ or in methanol in the presence of triethylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 203–205, February, 1985.     

Reaction of propiolic acid esters with dithiols and β-mercaptoethanol

2-Alkoxycarbonylmethyl-1,3-oxathiolane and -dithiolane, 3-methyloxycarbonylmethyl-7,8-dimethyl-1,5-dihydrobenzo[e]-1,3-dithiepine, and 2-methoxycarbonylmethyl-1,3-dithiolo[4,5-b]quinoxaline were synthesized on the basis of the reaction of esters of propiolic acid with -mercaptoethanol, 1,2-dimercaptoethanol, 1,2-dimethyl-4,5-di(mercaptomethyl)benzene, and 2,3-dimercaptoquinoxaline in chloroform medium in the presence of K₂CO₃ or in DMSO medium.Translated from Khimiya Geterotsilicheskikh Soedinenii, No. 8, pp. 1062–1065, August, 1984.     

Alkynyl derivatives of selenophene

The reaction of alkylacetylenes and acetylenes with 2-formylselenophene and its derivatives has given the previously unknown selenienyl alkynyl alcohols, which are oxidized to the corresponding ketones by MnO₂. The reactions of the latter with hydrazine and hydroxylamine were investigated, as a result of which selenienyl-substituted pyrazoles and isoxazoles were obtained.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 920–923, July, 1971.     

Synthesis of 2-acylmethyl- and 2-acylmethylene-1,3-dithiolo[4,5-b]quinoxalines from α-acetylenic ketones

A number of 2-acylmethyl-1,3-dithiolo[4,5-b]quinoxaline derivatives were synthesized on the basis of the reaction of -acetylenic ketones with quinoxaline-2,3-dithiol in dimethyl sulfoxide (DMSO) in the presence of K₂CO₃. Their monohydrochlorides were obtained. A new series of 2-acylmethylene-1,3-dithiolo[4,5-b]quinoxalines was obtained by the reaction of 1-bromo-2-acylacetylenes with quinoxaline-2,3-dithiol in DMSO in the presence of triethylamine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1489–1491, November, 1982.     

The synthesis of 5H-thiazolo[2,3-c][1,2,4]triazine derivatives and substituted 3-(2-acylvinylthio)-1,2,4-triazin-5-ones from 6-methyl-3-thioxo-1,2,4-triazin-5-one, 1-acyl-2-bromoacetylenes,and α-acetylenic ketones. X-ray study of 3-benzoyl-6-methyl-5H-thiazolo[2,3-c][1,2,4]triazin-5-one

3-Acyl-6-methyl-5H-thiazolo[2,3-c][1,2,4]triazines were synthesized by reaction of 1-acyl-2-bromoacetylenes with 6-methyl-3-thioxo-1,2,4-triazin-5-one in methanol in the presence of triethylamine at 20 °C. The structure of 3-benzoyl-6-methyl-5H-thiazolo[2,3-c][1,2,4]triazine was established by X-ray structural analysis. Substituted 3-(2-acetylvinylthio)1,2,4-triazin-5-ones were obtained by the reaction of -acetylenic ketones with 6-methyl-3-thioxo-1,2,4-triazin-5-one under the same conditions. The structures of the new compounds were confirmed by IR,¹H, and¹³C NMR spectroscopy.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2971–2975, December, 1996.     

Basic equations of the theory of thermoviscoelastic plates with distributed sensors and actuators

The basic equations of the theory of thermoviscoelastic thin-walled plates with piezoelectric sensors and actuators under monoharmonic mechanical and electric loading are derived using the Kirchhoff–Love hypotheses. The thermomechanical behavior of passive and piezoactive materials is described using the concept of complex characteristics. Methods of solving nonlinear problems of active damping of thermomechanical vibrations of plates with sensors and actuators are considered. The effect of dissipative heating on the damping of axisymmetric vibrations of a thermoviscoelastic solid circular plate is analyzed as an example     

Damping the flexural vibration of a clamped viscoelastic rectangular plate with piezoelectric actuators

The paper addresses the active damping of the resonant flexural vibration of a clamped 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 thermal 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