scholarly journals Вариационный подход к определению динамической прочности материала

2022 ◽  
Vol 92 (2) ◽  
pp. 274
Author(s):  
А.Д. Евстифеев ◽  
Г.А. Волков
Keyword(s):  
Test Performance ◽  
Tensile Tests ◽  
Strength Properties ◽  
Material Strength ◽  
Treatment Procedure ◽  
Performance Error ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars ◽  
Static Conditions

The problem of the determination of material strength properties through the Kolsky experimental technique is considered. Small size specimens of M1 copper alloy are tested on a split Hopkinson pressure bars equipment. The experimental data of tensile tests observed under both dynamic and quasi-static conditions are analysed within the framework of the incubation time criterion and the Sign-Perturbed Sums method. It is shown that the influence of a test performance error is considered in the data treatment procedure based on the developed method.

A Numerical Investigation into the Tensile Split Hopkinson Pressure Bars Test for Sheet Metals

2013 ◽  
Vol 421 ◽  
pp. 464-467 ◽  
Author(s):  
Thanh Nam Pham ◽  
Hyo Seong Choi ◽  
Jong Bong Kim
Keyword(s):  
Flow Stress ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Finite Element Analyses ◽  
Compressive Flow ◽  
Design Guide ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars

Determination of theflow stress of materials at high strain rate is very important in automotive and military areas.The compressive flow stress at high strain rate can be obtained relativelyexactly by SHPB(Split Hopkinson Pressure Bars) tests. However, it is difficult to determinethe flow stressexactlyin the tensile state by using the SHPB tests. The difficulty in the tensile SHPB tests is how to fix a specimen on two bars. So, the design of a specimen and holders is needed to obtain more accurate measurement of the flow stress. In this study, the accuracy of the tensile SHPB tests results was numerically investigated. Finite element analyses of the tensile SHPB were carried out for various cases of fixing bolt location and bolting force. From the analysis results, a design guide for the fixing structure was obtained and the causes of error were investigated.

Multiscale Fracture Model for Quasi-Brittle Materials

2011 ◽  
Vol 82 ◽  
pp. 160-165 ◽  
Author(s):  
Yuri V. Petrov ◽  
Vladimir Bratov
Keyword(s):  
Experimental Data ◽  
Brittle Fracture ◽  
Experimental Determination ◽  
Fracture Process ◽  
Strength Properties ◽  
Material Strength ◽  
Scale Level ◽  
Scale Levels ◽  
Real Scale

Fracture of quasi-brittle heterogeneous materials is steered by processes at several different scale levels. These processes can progress independently or affect each other. In order to model fracture of such materials one should account for all rupture processes contributing to overall fracture process. This paper is presenting structural-temporal approach for analysis of multiscale nature of brittle fracture. Notion of spatial-temporal cell for different scale levels is introduced. Problem of experimental determination of a fixed scale level is discussed. Possible interconnections of this scale level with higher and lower scale levels are discussed. It is shown that this can give a possibility to predict fracture on a higher (real) scale level having experimental data obtained on a lower (laboratory) scale. This possibility is of extreme importance for many applications where the possibility to evaluate material strength properties on real structure scale level does not exist (ex. geological objects, big concrete structures, trunk pipelines, etc.).

scholarly journals SANDY SOILS DYNAMIC STRENGTH PARAMETERS ACCORDING TO TRIAXIAL TESTS

2019 ◽  
Vol 14 (2) ◽  
pp. 24-33
Author(s):  
E. A. Sentsova ◽  
M. S. Nikitin ◽  
E. A. Voznesensky
Keyword(s):  
Dynamic Loading ◽  
Critical State ◽  
Dynamic Strength ◽  
Strength Properties ◽  
Triaxial Tests ◽  
Strength Parameters ◽  
Dynamic Conditions ◽  
Angle Of Internal Friction ◽  
Static Conditions

Correct determination of strength properties is always relevant for the prediction of the mechanical behavior of soils and their massifs. Under static loading conditions, the issue is prominent in domestic and foreign literature, but the determination of strength properties under dynamic loading causes theoretical and methodical issues. All developed types of tests, to date, describe particular cases of the reaction of a soil foundation under dynamic loading, a general scientific approach of determination of soil strength parameters in dynamic conditions has not been developed. The article describes the features of determining the strength and strength parameters of sand in static and dynamic conditions in triaxial tests. A review of current views on this topic is provided. On the basis of triaxial tests the method of determining the phase transformation point and the failure point is described. On the basis of the Coulomb-Mohr's strength theory and the critical state approach the strength parameters are determined. The test results concluded that the destruction of sand under both static and dynamic conditions occurs with the same ratio of normal, shearing and mean effective stresses and is described by a single critical state line (CSL), presented in the form of a bilinear equation. It has been experimentally proved that the strength of sand under static and dynamic conditions is different, the strength parameters are the same, that’s why the angle of internal friction (φ) and cohesion (C) of sand can be determined only under static conditions. At the same time to quantify the strength of soil, to assess the possibility of destruction of the soil requires a correct assessment of pore pressure, which implies conducting dynamic tests or modeling its accumulation.

Modified split Hopkinson pressure bars for dynamic bending and shear tests

2006 ◽  
Vol 134 ◽  
pp. 725-730 ◽  
Author(s):  
A. Pignon ◽  
G. Mathieu ◽  
S. Richomme ◽  
J. M. Margot ◽  
F. Delvare
Keyword(s):  
Shear Tests ◽  
Split Hopkinson ◽  
Split Hopkinson Pressure Bars ◽  
Dynamic Bending
Sign in / Sign up

Export Citation Format

Share Document