plasticity, complex loading, isotropy postulate, experimental data, strain trajectory, vector and scalar properties of material.

The results of experimental studies on validation Ilyushin’s isotropy postulate under the conditions of orthogonal complex loads along curvilinear trajectories of constant curvature. Experimental studies were carried out on thin-walled tubular specimens made of steel 45 on SN-EVM testing machine. Loading programs for tubular specimens were set in the deviatorial strain space of A.A. Ilyushin under the combined action of tension-compression and torsion on the specimens. Experimental data are obtained for four strain trajectories, which are circles starting from the origin. It is found that for the realized complex trajectories of constant curvature the isotropy postulate is fulfilled in terms of scalar and vector properties.

Alekseev, Andrey Alekseevich,

Ph.D. (Technical Sciences), Associate Professor, Department of Strength of Materials, Theory of Elasticity and Plasticity, Tver State Technical University, Tver, Russia,

Gultiaev, Vadim Ivanovich,

Doctor of technical sciences, Head of Department of Automobile roads, bases and foundations, Tver State Technical University, Tver, Russia,

Savrasov, Ivan Alexandrovich,

Postgraduate Student of the Department of Strength of Materials, Theory of Elasticity and Plasticity, Tver State Technical University, Tver, Russia,

Garanikov, Valery Vladimirovich,

Doctor of Technical Sciences, Head of the Department of Technical Mechanics, Tver State Technical University, Tver, Russia.