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Thermogravimetry combined with thermal gas titrimetry were used to study the ligand substitution reactions by mono- and diethanolamine in nickel(II) hexaamminochloride and copper(II) tetraamminosulfate. It has been shown that the reactions proceed in stages and the temperature intervals of the individual stages have been determined. The kinetics of the described reactions have also been studied at isothermal conditions. The Ea values of the reactions have been calculated on the basis of the data obtained. A reaction mechanism has been proposed.

An approximate procedure for calculating the limiting stress-strain state (SSS) of helically corrugated pipes that operate under an axial force is developed. The calculation reduces to determination of the elastoplastic SSS of a shell of revolution with a circular corrugation, which is under axial and torsional loads. The problem is solved using the geometrically nonlinear theory of shells in a quadratic approximation based on Kirchhoff-Love hypotheses, and relationships of the theory of deformation with respect to low-curvature trajectories. The SSS of a self-compensating helically corrugated pipe is investigated, the limiting axial load estimated, and good correspondence between the results obtained and experimental data indicated on the basis of the procedure that we developed.

The automated calculation system Plastichnost'-1 for ES-series computers is described. The system makes it possible to determine elastoplastic stress-strain states of elements of engineering structures designed as shells of rotation. It incorporates special-purpose applied program packages oriented toward resolving individual classes of problems for elastoplastic shells and service subsystems that facilitate the use of a data bank of physicomechanical properties of the materials and graph plotters for visual display of results.

A procedure is suggested for a numerical study of the axisymmetrical thermoelastoplastic stresss-train state of sections of a column of steam delivery pipes based on modelling a section of a shell of rotation with a proportionally reduced number of corrugations and lengths of cylindrical sections. The procedure is developed within the scope of the KirchhoffLove hypothesis on the basis of equations of the theory of simple loading processes taking their history into account. The procedure is substantiated by comparing calculated results for the stressstrain state of sections with eight and four corrugations.

Investigations were carried out into the stress-strain state of shells of revolution in a complex nonisothermal loading process on the basis of the structural model of a cyclicly unstable material. The results show that the use of this model of the material in the calculations of the shells of revolution in the nonisothermal multiparametric loading processes make it possible to greatly improve the accuracy of the results obtained on the basis of simpler plasticity theories, i.e., the theory of simple loading processes and the theory of processes of loading with a small curvature.

The article describes the study of the regularities of inelastic deformation of metal in isothermal complex processes of loading on paths in the form of two-link broken lines. The results of the experiments under complex loading of tubular specimens of heat-resistant alloy ÉI437 showed that the slope of the strain vector to the path of loading depends on the length of the arc of this path up to the point of its break; however, with the development of plastic deformations this dependence becomes weaker, and it may be neglected. The change of the slope of the strain vector to the path of loading depends on the temperature, and it does not depend on the speed of the loading process within the limits of its change by one order of magnitude; with angles of break of the path of loading exceeding p/2 the dependence of the above-mentioned slope of the strain vectors on the length of the arc of the path of loading past the point of its break is not universal.

A method is developed for approximate calculation of the thermoelastic stress-strain state of a section of a pipeline containing cylindrical and corrugated parts and operating under internal pressure with uniform heating. Determination of the stress-strain state in an approximate formulation is reduced to the calculation of a cylindrical sheel and one half-corrugation on the assumption that all of the half-corrugations are identical. The problem is solved within the framework of the Kirchhoff-Love hypotheses on the basis of equations of the theory of small elastoplastic strains. The method which is developed is used to study the character of the stress-strain state of a shell of revolution modeling a full-scale pipeline section. The calculated results agree well with experimental data.