METHOD OF DETERMINING RHEOLOGICAL CHARACTERISTICS AND LONG-TERM STRENGTH OF MATERIALS Russian patent published in 2019 - IPC G01N3/08 

FIELD: test technology.

SUBSTANCE: invention relates to testing materials, specifically to testing materials (rocks, construction materials, etc.) for creep and long-term strength at given stress and temperature levels. Method for determining rheological characteristics and long-term strength of material includes making a right cylindrical shape sample, application of the main voltage along its longitudinal axis to the sample and independent additional voltage along the normal to the cylinder side surface by means of its placement into the volumetric compression chamber, filled with the liquid under pressure, where the sample is then heated to the specified temperature value, thereafter, lengthwise and transverse deformations of the sample are recorded for a certain period of time. Novelty is that the sample is heated step-by-step to preset temperature values, wherein at each temperature change step, the main and additional stresses on the sample are independently varied, wherein with each step of varying voltages on the sample simultaneously recording its volumetric deformations, and periodic stabilization of stresses on the sample is also carried out step-by-step during certain time intervals using an external stable pressure source connected to the chamber of volumetric compression based on a substance in the equilibrium state of liquid and saturated steam, placed in a container with stabilized temperature, wherein the pressure stabilization time intervals are selected as required to achieve a constant rate of deformation of the sample or for onset of its destruction.

EFFECT: performing volume measurements of the sample and long-term strength of the material, in the description of the technique for creating and maintaining principal stresses on the sample with accuracy of the strain rate required for measuring the sample in the entire required range of natural deformation rates, as well as in successive change of conditions (temperature and stress state), at which there is a sample, reflecting dynamics of its deformation process until destruction.

9 cl, 3 dwg