ABSTRACT
The objective of the presented research is the mathematical formulation of the problem of thick-walled pipe loaded by the external pressure and by the stretching force in the thermal superplasticity range: differential balance equations; the kinematic ratios establishing the relationship between strain rates and displacements; an incompressibility condition in rates; the defining ratios in the form of the equations of the theory of elasto-plastic processes of small curvature, and the state equation which is a consequence of the dynamic model associated to isothermal process. Joint consideration of these equations leads to definition of one function which allows to establish stress fields, strain rates and displacements rates.
