scholarly journals Statistical Fracture Theory for Multiaxial Stress States Using Weibull's Three-parameter Function : Part 2 : Fracture under Biaxial Stress state

1983 ◽  
Vol 26 (219) ◽  
pp. 1461-1467
Author(s):  
Yohtaro MATSUO
Keyword(s):  
Stress State ◽  
Biaxial Stress ◽  
Multiaxial Stress ◽  
Biaxial Stress State ◽  
Fracture Theory ◽  
Stress States ◽  
Parameter Function

scholarly journals Mykhailo Dendiuk, Lyubomir Flud, Nazar Semenyshyn Software implementation of the construction of curves short-term strength of wood with biaxial stress state

2020 ◽  
Vol 8 ◽  
pp. 21-26
Author(s):  
Mykhailo Dendiuk ◽  
◽  
Lyubomir Flud ◽  
Nazar Semenyshyn ◽  
◽  
...  
Keyword(s):  
Stress State ◽  
Failure Criteria ◽  
Biaxial Stress ◽  
Term Strength ◽  
Short Term ◽  
Tangential Plane ◽  
Biaxial Stress State ◽  
Short Term Strength ◽  
Cross Platform ◽  
Stress States

This paper is devoted to implementing the algorithm for constructing short-term strength curves of wood with biaxial stress states in the radial-tangential plane of structural symmetry. To implement this algorithm was developed software based on the Qt cross-platform toolkit, which allows to build and analyze short-term strength curves in the cross section of wood. The created program has a possibility to choose one of three failure criteria, a kind of wood, temperature and humidity distribution of lumber. The C++ program code is designed so that you can easily add another type of wood as well as a failure criterion. To display the curves, you can select table or graph mode. Graphs can be fixed on a graphics widget, and new ones can be added to compare to previous ones. Based on the analysis of the constructed curves, the ultimate stress state of the material in partial cases is established. In conclusion about expedient using some criteria to describe the strength characteristics of wood with strong and weak asymmetry of strength limits.

Low Cycle Fatigue Crack Initiation of Rotating Structures Under Biaxial Stress States

2009 ◽  
Author(s):  
Chao Zhang
Keyword(s):  
Stress State ◽  
Crack Initiation ◽  
Low Cycle Fatigue ◽  
Cyclic Stress ◽  
Biaxial Stress ◽  
Test Results ◽  
Primary Stress ◽  
Biaxial Stress State ◽  
Fatigue Characteristics ◽  
Stress States

Rotating structures can experience biaxial stress states with a wide range of biaxiality ratios on structure surfaces. Low cycle fatigue (LCF) crack initiation in such conditions demonstrates different fatigue characteristics in terms of crack orientation, fatigue life, etc. The biaxial stress states can be categorized into two types: in-phase and out-of-phase under which fatigue characteristics can be significantly different according to rig test results. This paper presents an investigation of LCF crack initiation under in-phase and out-of-phase biaxial stress states based on rig test results of a nickel alloy. The crack orientations are reviewed and discussed at different stress states. Relations of biaxial LCF life debit factor vs biaxiality ratio are derived (the debit factor is defined as a ratio of the LCF life at a biaxial stress state to the LCF life at corresponding uniaxial stress state which has same cyclic and mean stresses as the primary cyclic and mean stressees of the biaxial stress state). The rig test results showed that the crack orientation is usually normal to the primary stress vector under in-phase biaxial stress states but is inclined to the primary stress vector under out-of-phase stress states. As per the derived biaxial LCF life debit factors, the LCF life was found to be slightly reduced with increasing biaxiality ratios under in-phase biaxial stress states but significantly reduced under out-of-phase biaxial stress states compared with corresponding uniaxial primary stress states. The equivalent cyclic stress fatigue criterion is also employed to theoretically model the biaxial LCF life debit factor under in-phase biaxial stress states. The hydrostatic cyclic stress is included in the equivalent cyclic stress in order to take into account the hydrostatic cyclic pressure effects. The equivalent cyclic stress in the criterion can physically reflect the materials’ ductility reduction under in-phase multiaxial stress states.

Об особенностях использования явления акустоупругости при контроле напряженного состояния анизотропного материала технических объектов при отрицательных температурах

2021 ◽  
pp. 23-32
Author(s):  
А.А. Хлыбов ◽  
А.Л. Углов ◽  
Д.А. Рябов
Keyword(s):  
Stress State ◽  
Uniaxial Stress ◽  
Modern Method ◽  
Biaxial Stress ◽  
Transverse Waves ◽  
Acoustic Anisotropy ◽  
Biaxial Stress State ◽  
Calculation Algorithms ◽  
Arctic Conditions ◽  
Stress States

The paper considers the features of using the modern method of acoustoelasticity for monitoring the uniaxial and biaxial stress state of acoustically anisotropic structural materials as part of technical objects operated in Arctic conditions. The features of using the method of acoustoelasticity for materials with different values of acoustoelastic coefficients, acoustic anisotropy and temperature dependence coefficients of acoustic parameters that appear in the calculation algorithms are analyzed. It has been established that the existing approaches to taking into account temperature effects in acoustoelastic calculations in a number of important cases lead to noticeable errors in determining mechanical stresses in the material of critical technical objects. In this case, taking into account the temperature corrections in a number of cases is necessary for both biaxial (planar) and uniaxial stress states. The presence of anisotropy of thermoacoustic coefficients of transverse waves for materials with anisotropy is shown experimentally. Refined calculation formulas are proposed for determining the uniaxial and biaxial stress state of an anisotropic material, taking into account the anisotropy of the thermoacoustic coefficients of transverse waves.

Characteristics of Residual Stress by Water-Jet Peening

2013 ◽  
Vol 768-769 ◽  
pp. 564-571 ◽  
Author(s):  
Kenji Suzuki ◽  
Takahisa Shobu ◽  
Ayumi Shiro
Keyword(s):  
Residual Stress ◽  
Stress State ◽  
Water Jet ◽  
Biaxial Stress ◽  
X Rays ◽  
Lattice Plane ◽  
Scanning Method ◽  
Depth Direction ◽  
Biaxial Stress State ◽  
Specimen Material

The specimen material was austenitic stainless steel, SUS316L. The residual stress was induced by water-jet peening. The residual stress was measured using the 311 diffraction with conventional X-rays. The measured residual stress showed the equi-biaxial stress state. To investigate thermal stability of the residual stress, the specimen was aged thermally at 773 K in air to 1000 h. The residual stress kept the equi-biaxial stress state against the thermal aging. Lattice plane dependency of the residual stress induced by water-jet peening was evaluated using hard synchrotron X-rays. The residual stress measured by the soft lattice plane showed the equi-biaxial stress state, but the residual stress measured by the hard lattice plane did not. In addition, the distributions of the residual stress in the depth direction were measured using a strain scanning method with hard synchrotron X-rays and neutrons.

Plastic behaviour of perforated sheets under biaxial stress state

1997 ◽  
Vol 39 (7) ◽  
pp. 781-793 ◽  
Author(s):  
Seung Chul Baik ◽  
Heung Nam Han ◽  
Sang Heon Lee ◽  
Kyu Hwan Oh ◽  
Dong Nyung Lee
Keyword(s):  
Stress State ◽  
Biaxial Stress ◽  
Plastic Behaviour ◽  
Biaxial Stress State ◽  
Perforated Sheets

Mastering the biaxial stress state in nanometric thin films on flexible substrates

2014 ◽  
Vol 306 ◽  
pp. 70-74 ◽  
Author(s):  
D. Faurie ◽  
P.-O. Renault ◽  
E. Le Bourhis ◽  
G. Geandier ◽  
P. Goudeau ◽  
...  
Keyword(s):  
Thin Films ◽  
Stress State ◽  
Biaxial Stress ◽  
Flexible Substrates ◽  
Biaxial Stress State

Application of a Multiaxial Fatigue Criterion for the Evaluation of Life of Gears of Complex Geometry

2003 ◽  
Author(s):  
Leonardo Borgianni ◽  
Paola Forte ◽  
Luigi Marchi
Keyword(s):  
Fatigue Life ◽  
Stress State ◽  
Life Prediction ◽  
Complex Geometry ◽  
Biaxial Stress ◽  
Fatigue Life Prediction ◽  
Random Loading ◽  
Complex Load ◽  
Biaxial Stress State ◽  
Principal Axes

Gears can show significant biaxial stress state at tooth root fillet, due to the way they are loaded and their particular geometry. This biaxial stress state can show a significant variability in principal axes during meshing. Moreover loads may have non predictable components that can be evaluated with the aid of recorded data from complex spectra. In these conditions, commonly adopted approaches for fatigue evaluation may be unsuitable for a reliable fatigue life prediction. This work is aimed at discussing a computer implementation of a fatigue life prediction method suitable for multiaxial stress states and constant amplitude or random loading. For random loading a counting procedure to extract cycles from complex load histories is discussed. This method, proposed by Vidal et al., is based on the r.m.s. value of a damage indicator over all the planes through the point where the fatigue life calculation is made. Miner’s rule is used for the evaluation of the overall damage. The whole fatigue life of the component is evaluated in terms of the numbers of repetitions of the loading block. FEM data are used to evaluate stresses under load. The implementation was validated using test data found in the technical literature. Examples of applications to gears are finally discussed.

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