Izvestiya of Saratov University.
Mathematics. Mechanics. Informatics
ISSN 1816-9791 (Print)
ISSN 2541-9005 (Online)

растяжение

Determination of elastic characteristics of polymeric covers by results of tests of flat specimens at tension and bending

 The results of experimental identification of elastic modulus and Poisson's ratio of thin polymeric covers on the surface of the flat specimens of steel 08-OP are presented. The values of elastic modulus were determined with the rule of the mixtures by the standard tests of the specimens with the covers at the tension and four-point bending. The values of the Poisson's ratio were obtained on the base of the comparison of the tests results and the computer modeling of the bending process the studied specimens.

Multimodulus Behevior of the Grained Composites on the Base of Unsaturated Polyetheres

The results of the investigation of elastic properties of grained composite based on the unsaturated polyetheres were presented. This material was designed to substitute natural rocks in civil and mechanical engineering. The experimental values of elastic modulus and the Poisson‘s ratio under the tension and compression were obtained. It was shown that the investigated composite exhibits the dependence of elastic properties on the type of the stress state.

Creep and Long-Term Strength Modeling for Thick-Walled Tubes under Combined Loading with Axial Force, Torsional Moment and Internal Pressure

We have developed a method for solving the boundary-value problem of rheological deformation and creep rupture of thick-walled tube under combined loading with axial force, torsional moment and internal pressure. Energetic variant of the theory of creep and long-term strength is used to describe creep process. Experimental verification of proposed method has been performed using known test data for creep and long-term strength of thick-walled tubes made of D16T alloy and Steel~20. Calculated dependencies for total axial strain and torsion angle on time are obtained.