scholarly journals The FEM Analysis of Stress Distribution in front of the Crack Tip and Fracture Process in the Elements of Modified and Unmodified Cast Steel G17CrMo5-5

2016 ◽  
Vol 10 (3) ◽  
pp. 201-206
Author(s):  
Robert Pała ◽  
Ihor Dzioba
Keyword(s):  
Stress Distribution ◽  
Cleavage Fracture ◽  
Crack Extension ◽  
Cast Steel ◽  
Experimental Studies ◽  
Fem Analysis ◽  
Initial Moment ◽  
Stress Distributions ◽  
Calculated Stress

Abstract The article presents influence of modification of the low-alloy cast steel G17CrMo5-5 by rare earth metals on stress distribution in front of the crack at the initial moment of the crack extension. Experimental studies include determination of strength and fracture toughness characteristics for unmodified (UM) and modified (M) cast steel. In the numerical computations, experimentally tested specimens SEN(B) were modelled. The true stress–strain curves for the UM and M cast steel are used in the calculation. The stress distributions in front of the crack were calculated at the initial moment of the crack extension. On the basis of data on the particle size inclusions in the UM and M cast steel, and the calculated stress distributions was performed an assessment of the possibility of the occurrence of cleavage fracture. The analysis results indicate that at room temperature for the UM cast steel, there is a possibility of cleavage fracture, while for the M cast steel occurrence of cleavage fracture is negligible.

scholarly journals Experimental – Numerical Analysis of Stress State in Front of the Crack Tip of Modified and Unmodified G17CrMo5-5 Cast Steel by Rare Earth Metals in a Brittle-Ductile Transition Region

2016 ◽  
Vol 61 (2) ◽  
pp. 1175-1181
Author(s):  
I. Dzioba ◽  
R. Pala ◽  
J. Kasinska
Keyword(s):  
Fracture Toughness ◽  
Rare Earth ◽  
Stress State ◽  
Numerical Analysis ◽  
Crack Extension ◽  
Cast Steel ◽  
Rare Earth Metals ◽  
Initial Moment ◽  
Brittle Ductile Transition

Abstract In the paper presented experimental data and numerical analysis of stress distribution in front of the crack of two melts of low-alloy G17CrMo5-5 cast steel-modified (M) by rare earth metals and original, unmodified (UM) in the temperature range, according to the brittle-ductile transition region. Experimental tests include determination of the tensile properties and fracture toughness characteristics for the UM and M cast steel. Numerical analysis includes determination of stress distribution in front of the crack at the initial moment of the crack extension. In the numerical computations, experimentally tested specimens SEN(B) were modeled. The true stress-strain curves for the UM and M cast steel were used in the calculation. It was shown that the maximum of the opening stresses at the initial moment of the crack extension occurs in the axis of the specimens and reaches similar level of about 3.5σ0 for both UM and M cast steel. However, the length of the critical distance, measured for stress level equal 3σ0, is great for the M in comparison to the UM cast steel. Also was shown that the UM cast steel increased the level of the stress state triaxiality parameters that resulted in a decrease of fracture toughness.

Experimental Studies on Abrasive Wear of Surface-Hardened and Shot Peened Alloy Cast Steels

2016 ◽  
Vol 674 ◽  
pp. 201-206
Author(s):  
Andrzej Norbert Wieczorek
Keyword(s):  
Abrasive Wear ◽  
Cast Steel ◽  
Experimental Studies ◽  
Operating Conditions ◽  
Linear Wear ◽  
Plastic Properties ◽  
Cast Steels ◽  
Wear Tests ◽  
Alloy Cast

The paper presents the results of wear tests of shot-peened and non-shot-peened cast steels with the use of an especially designed test rig simulating real operating conditions of chain wheels. The chain wheels subjected to tests were operated with the use of loose quartz abrasive. The studies involved the determination of strength and plastic properties, hardness distributions, microstructure and linear wear of the selected cast steels. Based on the results obtained, the following was found: the abrasive wear of cast steel chain wheels increased after shot peening.

Stress Distributions Analyzed in Bispherical Co-Ordinates

1960 ◽  
Vol 27 (4) ◽  
pp. 726-732 ◽  
Author(s):  
T. P. Mitchell ◽  
J. A. Weese
Keyword(s):  
Stress Distribution ◽  
Spherical Shell ◽  
Internal Pressure ◽  
Half Space ◽  
Linear Elasticity ◽  
Spherical Cavity ◽  
Point Load ◽  
Stress Distributions ◽  
Load Distributions

Boussinesq-Papkovich potentials are used in conjunction with the bispherical co-ordinate system to analyze three problems in the classical theory of linear elasticity: (a) The extension of the Boussinesq point-load problem to that in which the half-space contains a spherical cavity; (b) the determination of the stress distribution in an eccentric spherical shell under uniform internal pressure; (c) the determination of the stress distribution in a half-space containing a uniformly pressurized spherical cavity. Numerical results are presented for representative configurations and load distributions in each case.

scholarly journals Stress analysis of pressure-assisted sintering for the double-side assembly of power module

2019 ◽  
Vol 31 (1) ◽  
pp. 20-27 ◽  
Author(s):  
Yang Liu ◽  
Hao Zhang ◽  
Lingen Wang ◽  
Xuejun Fan ◽  
Guoqi Zhang ◽  
...  
Keyword(s):  
Stress Distribution ◽  
Fem Analysis ◽  
Stress Distributions ◽  
Sintering Process ◽  
Power Module ◽  
Content Type ◽  
Crack Generation ◽  
Power Modules ◽  
Key Issues ◽  
Simulation Results

PurposeCrack and stress distribution on dies are key issues for the pressure-assisted sintering bonding of power modules. The purpose of this research is to build a relationship among stress distributions, sintering sequences and sintering pressures during the sintering processes.Design/methodology/approachThree sintering sequences, S(a), S(b) and S(c), have been designed for the double-side assembly of power module in this paper. Experiments and finite element method (FEM) analysis are conducted to investigate the crack and stress distribution.FindingsThe sintering sequence had significant effects on the crack generation in the chips during the sintering process under 30-MPa pressure. The simulation results revealed that the module sintered by S(a) showed lower chip stress than those by the other two sintering sequences under 30 MPa. In contrast, the chip stress is the highest when the sintering sequence follows S(b). The simulation results explained the crack generation and prolongation in the experiments. S(a) was recommended as the best sintering sequence because of the lowest chip stress and highest yield rate.Originality/valueThis study investigated the stress distributions of the double-side sintered power modules under different sintering pressures. Based on the results of experiments and FEM analysis, the best sintering sequence design is provided under various sintering pressures.

scholarly journals Fem Analysis and Comparison of Single Fiber Pull-Out Tests

1997 ◽  
Vol 6 (4) ◽  
pp. 096369359700600 ◽  
Author(s):  
S. Feih ◽  
P. Schwartz
Keyword(s):  
Shear Stress ◽  
Stress Distribution ◽  
Fem Analysis ◽  
Shear Stress Distribution ◽  
Single Fiber ◽  
Stress Distributions ◽  
Fiber Coating ◽  
Uniform Shear ◽  
Pull Out ◽  
Microbond Test

This work analyses the stress distributions during the pull-out test and the microbond test by FEA. Both tests are found to lead to the same results. The simulation result predicts the in praxis calculated IFSS value. Fiber coating leads to a more uniform shear stress distribution.

Load and Stress Distributions in Spur and Helical Gears

1988 ◽  
Vol 110 (2) ◽  
pp. 197-202 ◽  
Author(s):  
V. Simon
Keyword(s):  
Regression Analysis ◽  
Stress Distribution ◽  
Tooth Profile ◽  
Stress Distributions ◽  
Contact Lines ◽  
Helical Gears ◽  
Local Contact ◽  
Alignment Errors

A method for the determination of load and stress distributions along the contact lines of the instantaneously engaged teeth of spur and helical gears is represented in this paper. The calculation includes the tooth profile modifications and crownings, manufacturing and alignment errors of gears, tooth deflections, local contact deformations of teeth, gear body bending and torsion, and deflections of supporting shafts. The influence of gear parameters on load and stress distributions is discussed. On the basis of the obtained results, by regression analysis, equations are derived for the calculation of load and stress distribution factors.

Predicting winding stresses for wound coils of non-linear orthotropic material

2004 ◽  
Vol 218 (1) ◽  
pp. 27-38 ◽  
Author(s):  
F R de Hoog ◽  
W Y D Yuen ◽  
M Cozijnsen ◽  
H-N Huynh
Keyword(s):  
Stress Distribution ◽  
Linear Theory ◽  
Orthotropic Material ◽  
Constitutive Relations ◽  
Industrial Applications ◽  
Stress Distributions ◽  
Forward Solution ◽  
Calculated Stress ◽  
Non Linear ◽  
Linear Material

In another work, the authors presented an analysis of stresses in wound coils under the assumption that the coil could be modelled as an orthotropic linear material. In this paper the authors extend the theory to the case where the constitutive relations of the coil material are non-linear. The approach adopted for both the linear and non-linear theory differs radically from that usually reported in this field of research. Instead of the traditional ‘forward solution’ of calculating stresses for a given winding policy, an ‘inverse solution’ is obtained in which the winding stresses required to achieve specified stress distributions in a coil are calculated. Stress distributions required to avoid coiling problems can often be specified. This method can therefore offer considerable advantages in industrial applications, since winding stresses required to achieve a specified stress distribution in a coil can be calculated directly. The non-linear solutions are compared to those for the linear case for different winding stresses and coil properties. An example of the effect of modifying the stress distribution in a coil on the winding stress is given to illustrate the advantage of this method.

Theoretical and experimental re-examination of a crack perpendicular to and terminating at the bimaterial interface

1993 ◽  
Vol 28 (1) ◽  
pp. 53-61 ◽  
Author(s):  
W C Wang ◽  
J T Chen
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Stress Distribution ◽  
Intensity Factor ◽  
Theoretical Analysis ◽  
Bimaterial Interface ◽  
Far Field ◽  
Stress Distributions ◽  
Stress Singularities

The plane problem of a crack that terminates perpendicularly to a bimaterial interface was re-examined both theoretically and experimentally. Using the complex variable method, the crack trip stress singularities and stress distributions were generalized. Digital photelastic technique was successfully employed to confirm the generalization of the theoretical analysis. The results showed that the so-called far-field effects indeed played a significant role in the stress distribution and determination of the stress intensity factor.

Improvement Of Curvilinear Diagrams Of Concrete Deformation

2019 ◽  
pp. 99-104
Keyword(s):  
Reinforced Concrete ◽  
Peak Load ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Deformation Model ◽  
Reinforced Concrete Structures ◽  
Significant Difference ◽  
Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

Energetic properties of peat saturated with petroleum products

2020 ◽  
Vol 13 (2) ◽  
pp. 105-109
Author(s):  
E. S. Dremicheva
Keyword(s):  
Crude Oil ◽  
Diesel Fuel ◽  
Energy Use ◽  
Experimental Studies ◽  
Calorific Value ◽  
Petroleum Products ◽  
Ash Content ◽  
Motor Oil ◽  
Initial Sample

This paper presents a method of sorption using peat for elimination of emergency spills of crude oil and petroleum products and the possibility of energy use of oil-saturated peat. The results of assessment of the sorbent capacity of peat are presented, with waste motor oil and diesel fuel chosen as petroleum products. Natural peat has been found to possess sorption properties in relation to petroleum products. The sorbent capacity of peat can be observed from the first minutes of contact with motor oil and diesel fuel, and significantly depends on their viscosity. For the evaluation of thermal properties of peat saturated with petroleum products, experimental studies have been conducted on determination of moisture and ash content of as-fired fuel. It is shown that adsorbed oil increases the moisture and ash content of peat in comparison with the initial sample. Therefore, when intended for energy use, peat saturated with petroleum products is to be subjected to additional drying. Simulation of net calorific value has been performed based on the calorific values of peat and petroleum products with different ratios of petroleum product content in peat and for a saturated peat sample. The obtained results are compared with those of experiments conducted in a calorimetric bomb and recalculated for net calorific value. A satisfactory discrepancy is obtained, which amounts to about 12%. Options have been considered providing for combustion of saturated peat as fuel (burnt per se and combined with a solid fuel) and processing it to produce liquid, gaseous and solid fuels. Peat can be used to solve environmental problems of elimination of emergency spills of crude oil and petroleum products and as an additional resource in solving the problem of finding affordable energy.

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