Unified Approach for Notch Stress Strain Conversion Rules

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Interpolation Method ◽  
Notch Root ◽  
Three Dimensional ◽  
Stress And Strain ◽  
Unified Approach ◽  
Stress Strain ◽  
Elastic Plastic ◽  
Strain Behavior ◽  
Notch Stress ◽  
Conversion Rules

There are several simplified methods, known as notch stress-strain conversion (NSSC) rules that provide an approximate formula to relate local elastic-plastic stresses and strains at the notch root to those estimated elastically. This paper investigates a unified approach that estimates nonlinear and history dependent stress-strain behavior of the notches using the conventional NSSC rules. A nonlinear interpolation method is adopted to estimate the elastic-plastic stress and strain at notches. A comparison is made between the finite element results for several notch configurations (with and without three-dimensional effects) and those obtained from NSSC rules and the proposed formulation.

Unified Approach for Notch Stress Strain Conversion (NSSC) Rules

2012 ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Interpolation Method ◽  
Notch Root ◽  
Three Dimensional ◽  
Linear Interpolation ◽  
Unified Approach ◽  
Stress Strain ◽  
Elastic Plastic ◽  
Strain Behavior ◽  
Notch Stress ◽  
Non Linear

There are several simplified methods, known as notch stress-strain conversion (NSSC) rules that provide an approximate formula to relate local elastic-plastic stresses and strains at the notch root to those estimated elastically. This paper investigates a unified approach that estimates non-linear and history dependent stress-strain behavior of the notches using the conventional NSSC rules. A non-linear interpolation method is adapted to estimate the elastic-plastic stress and strain at notches. A comparison is made between the finite element results for several notch configurations (with and without three dimensional effects) and those obtained from NSSC rules and the proposed formulation.

Improved Prediction Method for Estimating Notch Elastic-Plastic Strain

2009 ◽  
Vol 132 (1) ◽  
Author(s):  
R. Adibi-Asl ◽  
R. Seshadri
Keyword(s):  
Three Dimensional ◽  
Prediction Method ◽  
Inelastic Strain ◽  
Stress Concentrations ◽  
Stress Strain ◽  
Element Analysis ◽  
Simple Method ◽  
Elastic Plastic ◽  
Strain Behavior ◽  
Notch Stress

Notch stress-strain conversion (NSSC) rules are widely used to estimate nonlinear and history-dependent stress-strain behavior of the notch components or structures. This paper focuses on the estimation of stress and strain using the conventional NSSC rules and linear elastic analysis by considering the entire relaxation locus of the component during inelastic action. On the basis of local effects, net-section collapse, and reference stress, a simple method for estimating inelastic strain in the vicinity of stress concentrations is proposed. The accuracy of the method is compared with elastic-plastic finite element analysis for several notch configurations exhibiting two-dimensional and three-dimensional effects.

A Cyclic Stress-Strain Constitutive Model for Polycrystalline Magnesium Alloy and its Application

2007 ◽  
Vol 546-549 ◽  
pp. 81-88
Author(s):  
Xiang Guo Zeng ◽  
Qing Yuan Wang ◽  
Jing Hong Fan ◽  
Zhan Hua Gao ◽  
Xiang He Peng
Keyword(s):  
Magnesium Alloy ◽  
Constitutive Model ◽  
Cyclic Stress ◽  
Stress And Strain ◽  
Slip Systems ◽  
Stress Strain ◽  
Strain Behavior ◽  
Cast Magnesium ◽  
Magnesium Alloy Am60 ◽  
Good Agreement

The stress-strain behavior of cast magnesium alloy (AM60) was investigated by strain-controlled cyclic testing carried out on MTS. In order to describe the cyclic stress and strain properties of AM60 by means of the energy storing characteristics of microstructure during irreversible deformation, a plastic constitutive model with no yielding surface was developed for single crystal by adopting a spring-dashpot mechanical system. Plastic dashpots reflecting the material transient response were introduced to describe the plasticity of slip systems. By utilizing the KBW self-consistent theory, a polycrystalline plastic constitutive model for Magnesium alloy was formed. The numerical analysis in the corresponding algorithm is greatly simplified as no process of searching for the activation of the slip systems and slip directions is required. The cyclic stress-strain behavior, based on this model, is discussed. The simulation results show good agreement with the experimental data for AM60.

Stress and strain range predictions for axisymmetric and two-dimensional components with stress concentrations and comparisons with notch stress-strain conversion rule estimates

1993 ◽  
Vol 28 (3) ◽  
pp. 209-221 ◽  
Author(s):  
S J Hardy ◽  
A R Gowhari-Anaraki
Keyword(s):  
Finite Element ◽  
Strain Range ◽  
Load Level ◽  
Analytical Relationship ◽  
Stress And Strain ◽  
Two Dimensional ◽  
Stress Concentrations ◽  
Stress Strain ◽  
Notch Stress ◽  
Axisymmetric Problems

A comparison is made between finite element predictions of strain and strain range for hollow tubes with axially loaded axisymmetric internal projections and values obtained from the simple notch stress-strain conversin (NSSC) rules. Data from other published analyses, where notch strains were predicted, support this investigation. The comparison is made for a variety of monotonic and cyclic loads, material hardenning assumptions, and geometries. An intermediate rule ( m = 0.5) which appears to correlate with the finite element predictions to a reasonable degree of accuracy, is identified. In addition, an analytical relationship is suggested for calculating strain and strain range, in terms of load level, strain hardening assumption, and elastic stress concentration factor (SCF) for this type of axisymmetric component. Also, a comparison is made between some previously published experimental and numerical data, obtained for other two-dimensional and axisymmetric problems, and NSSC rule estimates in order to confirm the suitability of the intermediate rule. Finally, on the basis of these comparisons, an approximate procedure for predicting stress and strain ranges under conditions of gross yielding is presented for plane stress, plane strain, and axisymmetric problems.

scholarly journals Microstructural, Surface Topology and Nanomechanical Characterization of Electrodeposited Ni-P/SiC Nanocomposite Coatings

2019 ◽  
Vol 9 (14) ◽  
pp. 2901 ◽  
Author(s):  
Konstantinos Tsongas ◽  
Dimitrios Tzetzis ◽  
Alexander Karantzalis ◽  
George Banias ◽  
Dimitrios Exarchos ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Computational Models ◽  
Intermetallic Phase ◽  
Three Dimensional ◽  
Surface Topology ◽  
Nanocomposite Coatings ◽  
Stress Strain ◽  
Element Analysis ◽  
Strain Behavior ◽  
Heat Treated

In the present study, nickel phosphorous alloys (Ni-P) and Ni-P/ silicon carbide (SiC) nanocomposite coatings were deposited by electrodeposition on steel substrates in order for their microstructural properties to be assessed while using SEM, XRD, and three-dimensional (3D) profilometry as well as nanoindentation. The amorphisation of the as-plated coatings was observed in all cases, whereas subsequent heat treatment induced crystallization and Ni3P intermetallic phase precipitation. Examination of the surface topology revealed that the surface roughness follows the deposition characteristics and heat treatment induced microstructural changes. Additionally, substantial improvements in mechanical properties, including hardness, yield stress, and elasticity modulus, were obtained for the Ni-P, Ni-P/SiC nanocomposites when heat treated as seen from the nanoindentation results. A Finite Element Analysis (FEA) was developed to simulate the nanoindentation tests that enable the precise extraction of the Ni-P and Ni-P/SiC nanocomposite coatings’ stress-strain behavior. It is shown that the correlation between the nanoindentation tests and the computational models was satisfactory, while the stress-strain curves revealed higher yield points for the heat-treated samples.

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