Development of the Algorithm for Determination of Mechanical Properties of Steel 20 with Different Levels of Cumulative Fatigue Damage with the Application of Compact Samples

2018 ◽  
Vol 284 ◽  
pp. 581-586 ◽  
Author(s):  
R.N. Hasanov ◽  
A.S. Valiev ◽  
I.R. Kuzeev
Keyword(s):  
Mechanical Properties ◽  
Fatigue Damage ◽  
Bending Test ◽  
Large Samples ◽  
Study Results ◽  
Impact Bending ◽  
Cumulative Fatigue Damage ◽  
Steel 20 ◽  
Different Levels

Nowadays, a change of material properties is evaluated on the basis of the results of "traditional" methods (for example, tensile testing and impact bending test). Unfortunately, "traditional" mechanical testing requires quite large samples, that leads to a damage of studied objects integrity. That is why testing with the application of compact samples, which allows converting obtained results into regular parameters, such as tensile properties and fracture resistance, was developed. Due to the novelty of this method, influence of different factors on testing results is understudied. Here arises the aim to study the influence of the level of accumulated damage on testing results. Regular changes of small punch testing tensile diagrams, depending on the number of worked out cycles, are under study in the present paper. Based on the study results, algorithm for determination of mechanical properties of steel 20 with different levels of cumulative fatigue damage with the application of compact samples was developed.

scholarly journals Determination of mechanical properties of soil under laboratory conditions

2014 ◽  
Vol 60 (Special Issue) ◽  
pp. S66-S69 ◽  
Author(s):  
V. Malý ◽  
M. Kučera
Keyword(s):  
Mechanical Properties ◽  
Penetration Depth ◽  
Measuring Device ◽  
Laboratory Conditions ◽  
Measuring Network ◽  
Set Up ◽  
Different Diameters ◽  
Different Levels ◽  
Properties Of Soil

This paper presents the mechanical properties of soil. In order to determine the properties of soil under laboratory conditions, a special measuring device was constructed, viz. a bevameter. Two types of soil with different levels of moisture were examined and their mechanical properties were determined. Measurements were taken of non-compressed soil. A measuring network was set up, consisting of measuring and recording devices. In the course of measuring, the force and penetration depth of the pressing plate were recorded simultaneously. Three different diameters of pressing plate were used, namely 38, 50 and 70 mm. The pressure on the contact area was calculated after completion of the measurements, and the relationships between pressure and penetration depth were presented graphically.

Characterization and Evaluation of Mechanical Properties and Residual Stress in Aluminum-Magnesium Alloys Welded by the FSW Process

2020 ◽  
Vol 1012 ◽  
pp. 349-353
Author(s):  
D.B. Colaço ◽  
M.A. Ribeiro ◽  
T.M. Maciel ◽  
R.H.F. de Melo
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Residual Stresses ◽  
Welding Process ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Friction Stir ◽  
Aluminum Magnesium Alloys

The demand for lighter materials with suitable mechanical properties and a high resistance to corrosion has been increasing in the industries. Therefore, aluminum appears as an alternative due to its set of properties. The aim of this work was to evaluate residual stress levels and mechanical properties of welded joints of Aluminum-Magnesium alloy AA 5083-O using the Friction Stir Welding process. For mechanical characterization were performed a uniaxial tensile test, Vickers hardness, bending test and, finally, the determination of residual stresses. It was concluded that welding by FSW process with an angle of inclination of the tool at 3o, established better results due to better mixing of materials. The best results of tensile strength and a lower level of residual stresses were obtained using a tool rotation speed of 340 RPM with welding advance speed of 180 mm/min and 70 mm/min.

Closed-Form Spectral Fatigue Analysis for Compliant Offshore Structures

1988 ◽  
Vol 32 (04) ◽  
pp. 297-304
Author(s):  
Y. N. Chen ◽  
S. A. Mavrakis
Keyword(s):  
Closed Form ◽  
Fatigue Damage ◽  
Computational Cost ◽  
Power Spectra ◽  
Offshore Structures ◽  
Fatigue Analysis ◽  
Cumulative Fatigue Damage ◽  
High Computational Cost

Spectral fatigue analysis frequently has been applied to welded joints in steel offshore structures. Although, on the theoretical basis, the spectral formulation holds certain advantages over other formulations such as the discrete, design wave type of analysis, numerical methods developed on that basis generally suffer from the shortcomings of lack of precision and high computational cost. This paper synthesizes the uncertainties resulting from modeling errors that are regarded heretofore as unavoidable in an analysis. Such errors are traced to the approximations introduced in handling of wave data, in numerical integration of the response power spectra, and in the integration that leads to the determination of cumulative fatigue damage. To each of these sources of modeling error, a transparent, closed-form method is proposed which not only eliminates the potential errors but, surprisingly, improves the computational efficiency many times. The sensitivity of fatigue damage upon the variability of the shape parameter due to variability of wave environment for the so-called simplified analysis utilizing an idealized mathematical long-term probability density function (for example, the Weibull distribution) is also discussed.

Évaluation de la résistance à la fatigue des enrobés bitumineux fondée sur l'évolution de l'endommagement du matériau en cours d'essai : aspects fondamentaux et application à l'enrobé à matrice de pierre

2003 ◽  
Vol 30 (5) ◽  
pp. 902-913 ◽  
Author(s):  
Daniel Perraton ◽  
Hassan Baaj ◽  
Hervé Di Benedetto ◽  
Michel Paradis
Keyword(s):  
United States ◽  
Mechanical Properties ◽  
Standardized Tests ◽  
Fatigue Damage ◽  
The United States ◽  
New Approach ◽  
Stone Matrix Asphalt ◽  
Damage Rate ◽  
Stone Matrix

Fatigue of bituminous asphalts is one of the main types of pavement destruction. This phenomenon was studied extensively in Europe (RILEM) and in the United States (SHRP). There are no standardized tests in Quebec to assess asphalt fatigue resistance. In France, a new approach based on the determination of damage rates due to fatigue has been developed for a tension–compression test on asphalt core samples to study their fatigue strength. This paper presents a summary of the knowledge on asphalt fatigue. Damage rate analyses, developed by the DGCB (Département de Génie Civil et du Bâtiment) of the ENTPE at Lyon, is detailed and applied to stone matrix asphalt (SMA). Results show the validity of the approach by damage and the good fatigue damage strength of the SMA.Key words: bituminous asphalts, fatigue, complex module, damage, stone matrix asphalts (SMA), viscoelasticity, mechanical properties of bituminous asphalts.[Journal Translation]

scholarly journals FRACTURE ENERGY OF ILLITIC RAMMED EARTH WITH HIGH WATER-CLAY RATIO

2021 ◽  
Vol 30 ◽  
pp. 53-57
Author(s):  
Barbora Mužíková ◽  
Tereza Plaček Otcovská ◽  
Pavel Padevět
Keyword(s):  
Mechanical Properties ◽  
Fracture Energy ◽  
Strain Curve ◽  
High Water ◽  
Bending Test ◽  
Rammed Earth ◽  
Stress Strain Curve ◽  
The Earth ◽  
Maximum Value

The article is focused on design of mixture of rammed earth, producing, testing and determination of fracture energy of unfired rammed earth and its stress-strain curve in tensile bending test. Three different mixtures of rammed earth were designed and tested. The amount of water and binder is one of the key properties of the rammed earth, the amount of the water is expressed by the water-clay ratio. Mechanical properties of the earth material highly depend on the composition of sand, clay and water. The prescription AGL III with 80 % of sand, 20 % of clay and 0.400 water-clay ratio reached the maximum value of fracture energy 4.858±0.002 J/m2 and set AGL V had the minimum value 1.934±0.310 J/m2.

scholarly journals STUDYING OF THE SOURCES OF THE DESTRUCTION OF TURBINE GENERATOR BEARING MADE OF THE BABBIT OF GRADE B83

2019 ◽  
pp. 108-113
Author(s):  
O. V. Balina ◽  
V. V. Nassonov ◽  
V. I. Plehanov
Keyword(s):  
Mechanical Properties ◽  
Fatigue Damage ◽  
Microstructural Analysis ◽  
Electric Load ◽  
Turbine Generator ◽  
Friction Bearing ◽  
Modern Technologies

The article is devoted to the diagnostics of friction bearing of turbine generator and determination of the reasons of its destruction during exploitation. We have studied chemistry and mechanical properties of metal, have calculated strains acting on the shaft of turbine generator in the case of asymmetrical electric load. In the article we present the results of macrostructural and microstructural analysis with usage of modern technologies. According to the data diagnosis obtained, we conclude that the source of bearing destruction is babbit fatigue damage caused by asymmetrical electric load of generator. We recommend controlling the rate of bearing wear by monitoring of babbit components presence in oil and asymmetry of electric load to prevent similar destructions.

scholarly journals Determination of Mechanical Properties of Fiber Reinforced Concrete for Numerical Modelling

2020 ◽  
Vol 16 (1) ◽  
pp. 86-106
Author(s):  
Z. Marcalikova ◽  
R. Cajka
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Reinforced Concrete ◽  
Numerical Modelling ◽  
Fiber Reinforced Concrete ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Fiber Reinforced ◽  
Flexural Tensile Strength

AbstractThe paper deals with the determination of mechanical properties of fiber reinforced concrete in dependence on various dosages and recipe of concrete. The mechanical properties were determined for the default recipe of concrete, where the individual variants differ in the amount of fibers. The fibers dosing was 0, 25, 50 and 75 kg/m3. At the highest dosage of 75 kg/m3, the recipe is optimized with regard to the microstructure of the concrete. In the experimental program were determined compressive strength, modulus of elasticity, split tensile strength, flexural tensile strength and load-displacement diagram. The flexural tensile strength was determined based on a three-point and four-point bending test. Based on the evaluated data, the uniaxial tensile strength and the functional dependence for the resultant recipe of concrete with a dosage of 75 kg/m3 is with respect of the increasing importance and application of numerical modelling of building structures, the analysis is performed using non-linear calculation. The aim was to simulate the performed laboratory test and appropriately approximate the specific input parameters of the fiber reinforced concrete for nonlinear analysis.

Basic set of experiments for determination of mechanical properties of sand

2014 ◽  
Vol 62 (1) ◽  
pp. 129-137
Author(s):  
A. Sawicki ◽  
J. Mierczyński
Keyword(s):  
Mechanical Properties ◽  
Soil Mechanics ◽  
Physical And Mechanical Properties ◽  
Local Strain ◽  
Initial State ◽  
Laboratory Equipment ◽  
Additional Information ◽  
Basic Set ◽  
Initial Anisotropy

Abstract A basic set of experiments for the determination of mechanical properties of sands is described. This includes the determination of basic physical and mechanical properties, as conventionally applied in soil mechanics, as well as some additional experiments, which provide further information on mechanical properties of granular soils. These additional experiments allow for determination of steady state and instability lines, stress-strain relations for isotropic loading and pure shearing, and simple cyclic shearing tests. Unconventional oedometric experiments are also presented. Necessary laboratory equipment is described, which includes a triaxial apparatus equipped with local strain gauges, an oedometer capable of measuring lateral stresses and a simple cyclic shearing apparatus. The above experiments provide additional information on soil’s properties, which is useful in studying the following phenomena: pre-failure deformations of sand including cyclic loading compaction, pore-pressure generation and liquefaction, both static and caused by cyclic loadings, the effect of sand initial anisotropy and various instabilities. An important feature of the experiments described is that they make it possible to determine the initial state of sand, defined as either contractive or dilative. Experimental results for the “Gdynia” model sand are shown.

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