Experimental Studies of Biaxially Stressed Mild Steel in the Plastic Range

1948 ◽  
Vol 15 (3) ◽  
pp. 193-200
Author(s):  
S. J. Fraenkel
Keyword(s):  
Strain Path ◽  
Room Temperature ◽  
Stress Ratio ◽  
Experimental Studies ◽  
Uniaxial Stress ◽  
Biaxial Stress ◽  
Plastic Range ◽  
Static Tests ◽  
Stress States ◽  
Tubular Specimens

Abstract This paper describes static tests of tubular specimens of medium steel under biaxial stresses and at room temperature. The purposes of the tests were: (1) to obtain an experimental check on the so-called “third rule of plastic flow;” (2) to study the absorption of energy as a function of the biaxial stress ratio; and (3) to determine the effect of the path of loading as symbolized by the strain path. Within the range of conditions investigated, the path of loading was found to be immaterial. A relation between strain energies absorbed under biaxial and uniaxial stress states up to a common maximum strain is tentatively formulated.

A Hybrid Experimental-Numerical Test Specimen for Laminated Composite Materials

1991 ◽  
Vol 113 (3) ◽  
pp. 193-196
Author(s):  
W. K. Rule ◽  
G. E. Weeks
Keyword(s):  
Numerical Test ◽  
Cost Savings ◽  
Laminated Composite ◽  
Uniaxial Stress ◽  
Testing Procedure ◽  
Biaxial Stress ◽  
Element Analysis ◽  
Laminated Composite Materials ◽  
Stress States ◽  
A New Technique

A new technique is described for determining all four elastic constants of a lamina from a single laminated specimen of arbitrary, symmetric lay-up. This specimen is subjected to three different loading conditions, and the experimental data is reduced by means of a finite element analysis. The testing procedure for the specimen is relatively easy, which can result in considerable time and cost savings over traditional methods. The new specimen generates biaxial stress states. Thus, the material properties determined from such a configuration may be more appropriate for later use in structural analysis than those determined from traditional specimens with uniform uniaxial stress states.

Measurement of Biaxial Stress States in Silicon Using Micro-Raman Spectroscopy

2006 ◽  
Vol 73 (5) ◽  
pp. 745-751 ◽  
Author(s):  
Peter A. Gustafson ◽  
Stephen J. Harris ◽  
Ann E. O’Neill ◽  
Anthony M. Waas
Keyword(s):  
Raman Spectroscopy ◽  
Uniaxial Stress ◽  
Laboratory Frame ◽  
Silicon Wafers ◽  
Biaxial Stress ◽  
Micro Raman Spectroscopy ◽  
Multiaxial Stress State ◽  
Stress States ◽  
Stress Ratios

Micro-Raman spectroscopy is used to determine the multiaxial stress state in silicon wafers using a strategy proposed by Narayanan, et al. (J. Appl. Phys. 82, 2595–2602 (1997)) Previously, this strategy was validated when silicon was subjected to uniaxial stress in the laboratory frame (Harris, et al. J. Appl. Phys. 96, 7195–7201 (2004)). In the present work, silicon wafers have been analyzed that were subjected to biaxial stress states in the laboratory frame. The predicted curves for the initially degenerate F2g peaks were found to fall within the variability of the measured curves. Stress ratios were found to be predictable. Stress magnitudes were also found to be predictable, but are subject to uncertainty greater than 25%. To perform these tests, an apparatus has been developed which can provide controlled ratios of biaxial stress in a simple and compact test geometry. This fixture was used under a microscope, enabling in situ measurement of biaxial stress states.

Fatigue Life Parameter for Type 304 Stainless Steel Under Biaxial-Tensile Loading at Elevated Temperature

1999 ◽  
Vol 121 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Abdelkrim Zouani ◽  
Thang Bui-Quoc ◽  
Marie Bernard
Keyword(s):  
Stainless Steel ◽  
Fatigue Life ◽  
Stress Ratio ◽  
Biaxial Stress ◽  
304 Stainless Steel ◽  
Biaxial Tensile ◽  
The Mean ◽  
Stress States ◽  
Type 304 ◽  
Type 304 Stainless Steel

This paper describes a damage Parameter for predicting fatigue life under biaxial-tensile loadings. Several studies have focussed in the past on the situations where the in-plane biaxial stress ratio is negative; however, little attention has been paid for the cases involving both principal stresses in tension. A new testing method is used to carry out biaxial fatigue tests, at room and 427°C, on Type 304 stainless steel for different positive values of the stress ratio. In the experimental procedure, a disk-shaped specimen was used in connection with a spatial-arms mechanism which converts the uniaxial force generated by a conventional testing machine to radial forces extending the disk specimen. A modified virtual strain energy parameter is then suggested to normalize fatigue data obtained under a wide range of stress states. The proposed parameter accounts for the mean stress and the mean strain effects in an explicit form. In addition, the COD equivalent stress and strain concepts are adopted to account for the stress state biaxiality. The predictions of the proposed parameter are compared with the obtained experimental data and the correlation between the applied stress states and the experimental fatigue lives is discussed.

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.

Comparison of Substructures Between Uniaxial and Biaxial Deformation in 1100-0 Aluminum

1981 ◽  
Vol 39 ◽  
pp. 52-53
Author(s):  
D. L. Rohr ◽  
S. S. Hecker
Keyword(s):  
Plastic Strain ◽  
Cell Walls ◽  
Room Temperature ◽  
Mechanical Response ◽  
Biaxial Tension ◽  
Initial Deformation ◽  
Uniaxial Deformation ◽  
Biaxial Deformation ◽  
Stress States ◽  
Comprehensive Study

As part of a comprehensive study of microstructural and mechanical response of metals to uniaxial and biaxial deformations, the development of substructure in 1100 A1 has been studied over a range of plastic strain for two stress states.Specimens of 1100 aluminum annealed at 350 C were tested in uniaxial (UT) and balanced biaxial tension (BBT) at room temperature to different strain levels. The biaxial specimens were produced by the in-plane punch stretching technique. Areas of known strain levels were prepared for TEM by lapping followed by jet electropolishing. All specimens were examined in a JEOL 200B run at 150 and 200 kV within 24 to 36 hours after testing.The development of the substructure with deformation is shown in Fig. 1 for both stress states. Initial deformation produces dislocation tangles, which form cell walls by 10% uniaxial deformation, and start to recover to form subgrains by 25%. The results of several hundred measurements of cell/subgrain sizes by a linear intercept technique are presented in Table I.

Masonry: the brittle or plastic material?

2019 ◽  
pp. 22-28
Keyword(s):  
Plastic Material ◽  
Experimental Studies ◽  
Point Of View ◽  
Plastic Properties ◽  
Plastic Deformations ◽  
Base Materials ◽  
Stress States ◽  
Creep Deformations ◽  
Structural Point

The results of experimental studies of masonry on the action of dynamic and static (short-term and long-term) loads are presented. The possibility of plastic deformations in the masonry is analyzed for different types of force effects. The falsity of the proposed approach to the estimation of the coefficient of plasticity of masonry, taking into account the ratio of elastic and total deformations of the masonry is noted. The study of the works of Soviet scientists revealed that the masonry under the action of seismic loads refers to brittle materials in the complete absence of plastic properties in it in the process of instantaneous application of forces. For the cases of uniaxial and plane stress states of the masonry, data on the coefficient of plasticity obtained from the experiment are presented. On the basis of experimental studies the influence of the strength of the so-called base materials (brick, mortar) on the bearing capacity of the masonry, regardless of the nature of the application of forces and the type of its stress state, is noted. The analysis of works of prof. S. V. Polyakov makes it possible to draw a conclusion that at the long application of the load, characteristic for the masonry are not plastic deformations, but creep deformations. It is shown that the proposals of some authors on the need to reduce the level of adhesion of the mortar to the brick for the masonry erected in earthquake-prone regions in order to improve its plastic properties are erroneous both from the structural point of view and from the point of view of ensuring the seismic resistance of structures. It is noted that the proposal to assess the plasticity of the masonry of ceramic brick walls and large-format ceramic stone with a voidness of more than 20% is incorrect, and does not meet the work of the masonry of hollow material. On the basis of the analysis of a large number of research works it is concluded about the fragile work of masonry.

scholarly journals S235JRC+C Steel Response Analysis Subjected to Uniaxial Stress Tests in the Area of High Temperatures and Material Fatigue

2021 ◽  
Vol 13 (10) ◽  
pp. 5675
Author(s):  
Josip Brnic ◽  
Marino Brcic ◽  
Sebastian Balos ◽  
Goran Vukelic ◽  
Sanjin Krscanski ◽  
...  
Keyword(s):  
High Temperatures ◽  
Room Temperature ◽  
Uniaxial Stress ◽  
Fatigue Tests ◽  
Experimental Investigations ◽  
Response Analysis ◽  
Stress Tests ◽  
Staircase Method ◽  
Mechanical Fatigue ◽  
Proper Material

Knowledge of the properties and behavior of materials under certain working conditions is the basis for the selection of the proper material for the design of a new structure. This paper deals with experimental investigations of the mechanical properties of unalloyed high quality steel S235JRC + C (1.0122) and its behavior under conditions of high temperatures, creep and mechanical fatigue. The response of the material at high temperatures (20–700 °C) is shown in the form of engineering stress-strain diagrams while that at creep behavior (400–600 °C) is shown in the form of creep curves. Furthermore, based on uniaxial fully reversed mechanical fatigue tests (R=−1), a stress-life (S-N) fatigue diagram has been constructed and the fatigue (endurance) limit of the material is calculated The experimentally determined value of tensile strength at room temperature is 534 MPa. The calculated value of the fatigue limit, also at room temperature, using the modified staircase method and based on the mechanical fatigue tests data, is 202 MPa. With regard to creep resistance, steel 1.0122 can be considered creep-resistant only at a temperature of 400 °C and at an applied stress not exceeding 50% of the yield strength corresponding to this temperature.

A Study of Strain and Strain-Rate Dependent Properties of a Superplastic Zn-Al Alloy Under Biaxial Stresses

1982 ◽  
Vol 104 (1) ◽  
pp. 41-46
Author(s):  
T. C. Hsu ◽  
I. M. Bidhendi
Keyword(s):  
Strain Rate ◽  
Stress Ratio ◽  
Local Stress ◽  
Biaxial Stress ◽  
Al Alloy ◽  
Local Geometry ◽  
Forming Process ◽  
Rate Dependent ◽  
Strain And Strain Rate ◽  
Liquid Behavior

A superplastic Zn-Al alloy in sheet form is formed into a bulge over a circular hole by pneumatic pressure. The geometry, the stress, the strain, and the strain-rate are determined at various points covering the whole specimen and at various stages of the forming process. The complicated shape, and its complicated changes, are represented by introducing an index for the local geometry, called “prolateness,” which is also related to the local stress ratio in a simple way. The biaxial stress is analyzed into a strain-proportional and a strain-rate-proportional component, which represent, respectively, the quasi-solid and the quasi-liquid behavior of the superplastic material.

Cumulative Damage in Fatigue under Multiaxial Stress Conditions

1974 ◽  
Vol 188 (1) ◽  
pp. 423-430 ◽  
Author(s):  
D. L. Mcdiarmid
Keyword(s):  
Experimental Investigation ◽  
Aluminium Alloy ◽  
Principal Stress ◽  
Stress Ratio ◽  
Uniaxial Stress ◽  
Cumulative Damage ◽  
Stress Conditions ◽  
Multiaxial Stress ◽  
Stress Ratios ◽  
Damage Criteria

Previous investigations into cumulative damage fatigue under uniaxial stress are discussed in conjunction with the parameters relevant to the present experimental investigation. The results of two-level block programme tests on 2L65 aluminium alloy at four values of constant principal stress ratio and at several combinations of two different principal stress ratios are presented and discussed with reference to cumulative damage criteria developed for the case of uniaxial fatigue stress.

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