Numerical Analysis of the Stress State of the Pelvic Bone after Hip Hemiarthroplasty

2009 ◽  
Author(s):  
J. Jíra ◽  
J. Jírová ◽  
D. Kytýr ◽  
M. Micka ◽  
J. Bartonícek
Keyword(s):  
Stress State ◽  
Numerical Analysis ◽  
Pelvic Bone ◽  
Hip Hemiarthroplasty

scholarly journals Numerical analysis of stress-state-dependent damage and failure behavior of ductile steel based on biaxial experiments

2020 ◽  
Author(s):  
Michael Brünig ◽  
Marco Schmidt ◽  
Steffen Gerke
Keyword(s):  
Stress State ◽  
Numerical Analysis ◽  
Numerical Model ◽  
Evolution Equations ◽  
Image Correlation ◽  
Failure Behavior ◽  
Damage And Failure ◽  
State Dependent ◽  
Ductile Steel ◽  
Biaxial Experiments

Abstract The paper deals with a numerical model to investigate the influence of stress state on damage and failure in the ductile steel X5CrNi18-10. The numerical analysis is based on an anisotropic continuum damage model taking into account yield and damage criteria as well as evolution equations for plastic and damage strain rate tensors. Results of numerical simulations of biaxial experiments with the X0- and the H-specimen presented. In the experiments, formation of strain fields are monitored by digital image correlation which can be compared with numerically predicted ones to validate the numerical model. Based on the numerical analysis the strain and stress quantities in selected parts of the specimens are predicted. Analysis of damage strain variables enables prediction of fracture lines observed in the tests. Stress measures are used to explain different stress-state-dependent damage and failure mechanisms on the micro-level visualized on fracture surfaces by scanning electron microscopy.

Stress State of Shells With Residual Strains: Refined Model and Matrizant Method

2008 ◽  
Author(s):  
Alexander V. Maksymuk ◽  
Natalie N. Shcherbyna ◽  
Lyubomyr S. Shlapak
Keyword(s):  
Theoretical Model ◽  
Stress State ◽  
Numerical Analysis ◽  
Analytical Method ◽  
Axisymmetric Problem ◽  
Refined Model ◽  
Transversal Shear ◽  
Residual Strains ◽  
Numerical Analytical Method

An axisymmetric problem on determination of the stress state for limited cylindrical shells caused by residual strains is considered. Using of suggested matrizant numerical-analytical method the solution of this problem in refined statement is given. The theoretical model allows taking into account of the effect of transversal shear deformation and the compression of normal. Numerical analysis of the stress state is presented.

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.

scholarly journals GROUND OF PARAMETERS OF DISCRETISATION AT THE NUMERICAL ANALYSIS OF NON-CIRCULAR OUTLINE TUNNELS

2017 ◽  
pp. 20-29
Author(s):  
V. P. KUPRIY ◽  
O. L. TIUTKIN ◽  
P. YE. ZAKHARCHENKO
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Element Model ◽  
Finite Element Models ◽  
Railway Tunnel ◽  
Tunnel Support ◽  
Strain Stress ◽  
Circular Outline

Purpose. Influence on the strain-stress state of discretization of finite element model in the numerical analysis of non-circular outline tunnels is explored in the article. Methodology. For achievement of the put purpose, authors developed three finite element models of callote part at building of two-line railway tunnel. In each of models in a programmatic complex «Lira» was a concrete method of discretization area of cooperation with the temporal fastening. After creation of models, their numerical analysis with the detailed research of his results was conducted. Findings. The values of deformations and tensions of finite element models on horizontal and vertical axes, and also maximal values of moments and longitudinal forces in the temporal support are got. The comparative analysis of the got values is conducted. The graphs of conformities to the law of the indicated results from the features of discretization of two models are built. The third finite element model with the radial laying out of knots in the area of co-operation of the temporal fastening with the surrounding ground array is explored. Originality. It is set that at the numerical analysis of SSS of tunnel support of non-circular outline his results substantially depend on a form, sizes and configuration of the applied finite elements, from the sizes of calculation area of the ground massif, and also from the terms of his fixing (maximum terms). Practical value. The features of discretization and necessary sizes of calculation area of the ground massif at the design of the system are certain «support – ground massif », which provide sufficient exactness of calculation of parameters of the strain-stress state of support.

scholarly journals Designing A New Suitable Support System for Deep Virgin Coal Mining Blocks of Godavari Valley Coalfield

2021 ◽  
Author(s):  
Vikram Shankar ◽  
Dheeraj Kumar ◽  
Duvvuri Satya Subrahmanyam
Keyword(s):  
Stress State ◽  
Numerical Analysis ◽  
Coal Mining ◽  
Support System ◽  
Three Dimensional ◽  
Hazard Mapping ◽  
Mine Design ◽  
Analysis Study ◽  
Sophisticated Method ◽  
Godavari Valley

Abstract Importance of support system in mine design gained pace after modern way of approach took birth through many variants. A suitable support system is designed for deep virgin coal mining blocks of Godavari valley coalfield in India. This is achieved by measuring stress state by sophisticated method followed by geotechnical hazard mapping for identifying potential roof instability, predict hazards in advance and integrating the above parameters for analyze effects on stress due to different mining geometries by using numerical modelling technique. The three-dimensional numerical analysis study pours much light on effects causing instability than the 2D program. The results show that the stresses at an angle to the Level galleries are adverse. The level gallery/dip-raise may be oriented at 200 to 400 to reduce roof problems.

scholarly journals Equilizing of the Primary Stress State in the Rock Mass, Simulated by a Model of Layer in an Elastic-Viscous Medium

2016 ◽  
Vol 61 (4) ◽  
pp. 853-873
Author(s):  
Grzegorz Kortas
Keyword(s):  
Rock Mass ◽  
Stress State ◽  
Numerical Analysis ◽  
Creep Compliance ◽  
Viscous Medium ◽  
Mass Model ◽  
Effective Stresses ◽  
Model Studies ◽  
Primary Stress ◽  
The Relationship

Abstract This paper is devoted to the analysis of the stress development process in the homogeneous and non-homogeneous rock mass. The rock-mass model consists of an elastic-viscous medium containing a layer (Fig. 1) that displays distinct geomechanical strain properties. When examining the process of stress equilizing in time, the Norton-Bailey power creep law was applied in the numerical analysis. The relationship between effective stresses and time, the modulus of elasticity, Poisson’s coefficient, and creep compliance were obtained. It was demonstrated that the relationship between effective stress and time or creep compliance, for the assumed conditions in a homogeneous rock-mass, was approximated by hyperbolic functions (10 and 16). The process parameter included a certain value of creep compliance or of time at which there occurred a half-way equilizing of primary stresses. An analogous function binds effective stresses with creep compliance. Our model studies indicated a number of relationships between bulk and shear strain with time and creep compliance in the homogeneous and non-homogeneous rock mass, presented in Figs. 2-14, expressed by the functions of those specific parameters. The relationships obtained in this work resulted from our model assumptions. However, they demonstrated the influence of the geomechanical strain properties of rocks on the process of shaping the primary stress state in the rock mass and the tendency to reduce the principal stress differences in time. Our research results suggested the necessity to simulate the primary stress state as an initial condition of the geomechanical numerical analysis concerning the rock-mass behaviour showing rheological properties.

On the Methodology of Numerical Etching

1999 ◽  
Vol 563 ◽  
Author(s):  
X. H. Wang ◽  
K. Shyu ◽  
C.-T. Chang ◽  
D. W. Zheng ◽  
Weijia Wen
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Stress State ◽  
Numerical Analysis ◽  
Stress Distribution ◽  
Stress Field ◽  
Initial Stress ◽  
Silicon Wafer ◽  
Initial Stress Field ◽  
Actual Stress

AbstractA methodology to study the stress distribution of a patterned thin film residing on a silicon wafer was developed. Si underlying the pattern was thinned down through etching so that the deformation caused by residual stress in the microstructure could be detected by a Twyman- Green interferometer. A procedure called "numerical etching" was implemented to simulate the etching process, which linked the stress state of the microstructure on a regular wafer to that on a Si diaphragm. An initial stress field on the pattern was assumed, and its effect on the deformation of the Si diaphragm beneath was calculated and compared with experimental results. The discrepancy between them was used to modify the initially assumed stress field and repeated until a satisfactory match was achieved. The stress field from numerical analysis accurately predicts the actual stress distribution in and around the patterned structure under investigation. The stress distribution in a Ti pad on a Si3N4/ SiO2/Si composite diaphragm is used as an example.

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