Assessing the Fatigue Strength of Structural Materials by Assuming Equivalence of a Complex Stress State and Simple Extension. 1. Review of Experimental Data and Preliminary Analysis

2021 ◽  
Vol 41 (12) ◽  
pp. 1145-1148
Author(s):  
P. N. Kozlov
Keyword(s):  
Experimental Data ◽  
Fatigue Strength ◽  
Stress State ◽  
Preliminary Analysis ◽  
Structural Materials ◽  
Complex Stress ◽  
Complex Stress State ◽  
Simple Extension

Application of the concept of criterion of a complex stress state to a simple tension for appraisal of resistance of fatigue of structural materials. Part 2. Drawing up criterion and its checking on compliance to experimental data

2021 ◽  
pp. 41-45
Author(s):  
P.N. Kozlov
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Structural Material ◽  
Complex Stress ◽  
Complex Stress State ◽  
Static Loads ◽  
Regular Change ◽  
Regular Cycle ◽  
Simple Tension ◽  
Dangerous Point

The criterion for appraisal of resistance of fatigue of structural material at action on it of repeatedly variables loads and static loads in the form of a bend or tensioncompression together with torsion, and also at action of loads, which create two-axis regular change of stress state in a dangerous point of material is constructed. The received criterion will acceptable be coordinated with the known experimental data. Keywords: dangerous point of material, regular cycle of loading, equivalent amplitude, equivalent average stress, chart of extreme amplitudes of stresses. [email protected]

Fatigue strength of materials in a complex stress state

2010 ◽  
Vol 30 (1) ◽  
pp. 23-25
Author(s):  
A. E. Tsybul’ko ◽  
E. A. Romanenko
Keyword(s):  
Fatigue Strength ◽  
Stress State ◽  
Complex Stress ◽  
Complex Stress State ◽  
Strength Of Materials

Modeling of the High Temperature Creep and Rupture under the Complex Stress State

2016 ◽  
Vol 870 ◽  
pp. 528-534 ◽  
Author(s):  
T.R. Stepanova ◽  
T.V. Prokhorova
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Damage Mechanics ◽  
Complex Stress ◽  
Complex Stress State ◽  
Creep Rupture ◽  
Creep Failure ◽  
Notched Specimens ◽  
Mechanics Model ◽  
Calculation Results

A damage mechanics model linked to the creep strain and stress three-axiality has been adopted to predict the creep lifetime under the complex stress state. The model accounts for primary-secondary-tertiary creep laws. Constitutive equation parameters were determined using experimental data of smooth specimens. Finite element modeling of creep rupture in notched specimens is presented in this work. The calculated creep failure strain and time to rupture for notched specimens (semicircular with radius 4.0 mm and U-notched with radius 1.2 mm) have been compared with experimental data for the X10CrMoVNb-9-1 steel tested at 625 °C. The calculation results of creep rupture for smooth and notched specimens show notch strengthening or notch weakening depending on the tensile stresses level and notch geometry.

scholarly journals Fatigue Life of Construction Elements in a Complex Stress State

2014 ◽  
Vol 6 ◽  
pp. 585262 ◽  
Author(s):  
Krzysztof Łukaszewicz
Keyword(s):  
Fatigue Strength ◽  
Stress State ◽  
Theoretical Calculations ◽  
Fracture Initiation ◽  
Complex Stress ◽  
Complex Stress State ◽  
Slip Systems ◽  
Unit Radius ◽  
The Moment ◽  
Suggested Criterion

This paper presents a method of assessing fatigue strength for a body in conditions of cyclical tension and torsion. The theoretical calculations have been conducted using the criterion of averaged structural microdamage resulting from local slips. The description of microdamages of such a body, in the view of the slip concept, was done by using a half-sphere with a unit radius, on the surface of which the location of all local physical planes and slip systems was determined employing three angles. A computer method was used to determine the slip boundaries in a complex stress state, analyzing the slip condition for all combinations of angles. Based on the calculated values of the microdamages' intensity function, the number of loading cycles until the moment of fracture initiation was estimated. Experimental verification of the suggested criterion was conducted using cylindrical smooth specimens, made of C45 steel. The tests of fatigue strength were made under conditions of a constant amplitude of zero-start pulsating loads.

Creep Rupture of Anisotropic Pipes

1998 ◽  
Vol 120 (3) ◽  
pp. 223-225 ◽  
Author(s):  
S. A. Shesterikov ◽  
A. M. Lokochtchenko ◽  
E. A. Mjakotin
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Anisotropic Material ◽  
Complex Stress ◽  
Complex Stress State ◽  
Creep Rupture ◽  
Suggested Method ◽  
Strength Anisotropy ◽  
Anisotropy Coefficient ◽  
Thin Walled

The problem of creep rupture of pipes from an anisotropic material is studied. The authors suggest a method describing the results of creep rupture tests on thin-walled pipes under complex stress state by taking the strength anisotropy of material into account. A coefficient of strength anisotropy has been determined from the results of creep rupture testing, and a method is given for calculation under various modes of complex stress state. This procedure is based on evaluating the values of the statistical spread from the experimental data. The anisotropy coefficient corresponding to the minimum spread is adopted. The suggested method of calculating the strength anisotropy coefficient is confirmed experimentally.

Shear band evolution related with thermal annealing revealing ductile-brittle transition of Zr35Ti30Be27.5Cu7.5 metallic glass under complex stress state

2022 ◽  
Vol 140 ◽  
pp. 107378
Author(s):  
Xiangkui Liu ◽  
Tianchi Wang ◽  
Qipeng Wang ◽  
Xinxiang Song ◽  
Yuzheng Liang ◽  
...  
Keyword(s):  
Stress State ◽  
Shear Band ◽  
Metallic Glass ◽  
Thermal Annealing ◽  
Complex Stress ◽  
Complex Stress State ◽  
Brittle Transition

Application of the concept of the criterion of equivalence of complex stress state to simple tension for assessing the fatigue resistance of structural materials. Part 1. Review of some experimental data with the preparation of the necessary information for subsequent use

2021 ◽  
pp. 24-27
Author(s):  
P.N. Kozlov
Keyword(s):  
Stressed State ◽  
Fatigue Resistance ◽  
Numerical Data ◽  
Structural Materials ◽  
Complex Stress ◽  
Complex Stress State ◽  
Static Loads ◽  
Simple Tension ◽  
Long Time ◽  
Equivalence Criterion

A brief overview of the features of the fatigue resistance of some steels is given with the selection of terms, concepts and numerical data necessary for the subsequent compilation and verification of the equivalence criterion in relation to assessing the ability of structural materials to resist fatigue for a long time under the action of certain combinations of alternating and static loads. Keywords: regular loading cycle, extremely stressed state, static stressed state, bending, torsion, biaxial static tension. [email protected]

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