Experimental Studies of Elastic–Plastic Deformation of Structural Materials Under Conditions of Triaxial Loading

Abstract

The behavior of metal tubular specimens under combined tension–torsion, torsion–compression and internal torsion pressures is studied experimentally. The tests are necessary for obtaining experimental data in order to study loss of stability and deformation of elastic–plastic shells caused by large deformations under complex stress conditions loaded along multi-link broken polygonal deformation trajectories, as well as for assessing the role of deformation anisotropy. In order to conduct tests under complex stress conditions (internal pressure loading in combination with other types of loading), the testing equipment was modified. Equipment of the test complex with a system for loading of tubular specimens with internal pressure ensures the conditions for achieving destructive stresses, caused by both internal pressure and torsion with tension. The Zwick/Roell Z100 testing machine equipped with the system generating internal pressure in hollow specimens makes it possible to expand significantly the types of tests on determining deformation and strength characteristics of materials. The results can be used to verify mathematical models and program codes for the numerical study of the processes of elastic–plastic deformation and loss of stability of shells of revolution under complex loading.