Extraction of polymer stress-strain behavior in the presence of self-heating by the use of a simple model for the elastic-plastic deformation

2015 ◽  
Vol 55 (11) ◽  
pp. 2474-2481 ◽  
Author(s):  
Chrystelle A Bernard ◽  
Christophe Fond ◽  
Saïd Ahzi ◽  
Nadia Bahlouli
Keyword(s):  
Plastic Deformation ◽  
Simple Model ◽  
Stress Strain ◽  
Elastic Plastic ◽  
Strain Behavior ◽  
Self Heating

Thermal Elastic-Plastic Analysis Considering Temperature Rise by Rapid Plastic Deformation in Undermatched Joints

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
Masahito Mochizuki ◽  
Gyu-Baek An ◽  
Masao Toyoda
Keyword(s):  
Plastic Deformation ◽  
Strain Rate ◽  
Temperature Rise ◽  
Structural Steels ◽  
Stress Strain ◽  
Elastic Plastic ◽  
Strain Behavior ◽  
Maximum Loading ◽  
Coupling Phenomena ◽  
Rapid Plastic Deformation

The characteristics of dynamic strength and fracture in structural steels and their welded joints particularly for pipelines should be evaluated based on the effects of the strain rate and service temperature. The temperature, however, rises so rapidly in structures due to the plastic work under the high strain rate such as ground sliding by earthquake when the effect of the temperature cannot be negligible for the dynamic fracture. It is difficult to predict or measure the temperature rise history with the corresponding stress-strain behavior, including the region beyond the uniform elongation, though the behavior at the large strain region after the maximum loading point is very important for the evaluation of fracture. In this paper, the coupling phenomena of the temperature and stress-strain fields under dynamic loading were simulated by using the finite element method. A modified rate-temperature parameter was defined by accounting for the effect of the temperature rise under rapid plastic deformation, and it was applied to the fully coupled analysis between the heat conduction and thermal elastic-plastic behavior. The temperature rise and stress-strain behavior, including the coupling phenomena, were studied including the region beyond the maximum loading point in structural steels and their undermatched joints, and then compared with the measured values.

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.

Orowan-Based Deformation Model for Layered Metallic Materials

1996 ◽  
Vol 434 ◽  
Author(s):  
Eric R. Kreidler ◽  
Peter M. Anderson
Keyword(s):  
Plastic Layer ◽  
Deformation Model ◽  
Metallic Materials ◽  
Stress Strain ◽  
Dislocation Interaction ◽  
Line Energy ◽  
Elastic Plastic ◽  
Strain Behavior ◽  
Dislocation Pileups ◽  
Deformation Modes

AbstractAn Orowan-based deformation model for layered metallic materials is presented and used to calculate the stress-strain behavior for two deformation modes. This model assumes that layer thicknesses are sufficiently small so that single rather than multiple dislocation pileups form. Deformation then proceeds by increasing the density of single dislocation pileups. Furthermore, it is assumed that the controlling stress for plastic deformation is that to propagate a tunneling dislocation loop inside an embedded elastic-plastic layer. Initially, the resolved stress required to propagate an isolated tunneling loop does not depend on whether the loop shears the layer perpendicular to an interface or stretches it parallel to an interface. At larger strains, the tunneling arrays become sufficiently dense such that local dislocation interaction changes the line energy of a tunneling dislocation. As a result, the elastic-plastic layers may exhibit modest softening when sheared or substantial hardening when stretched. When the elastic-plastic layers are embedded into a multilayered specimen with alternating elastic-only layers, no macroscopic strain softening is observed. However, the predicted macroscopic stress-strain curves for stretching and shearing are significantly different in their dependence on layer thickness.

An Analysis of Longitudinal Elastic-Plastic Pulse Propagation

1966 ◽  
Vol 33 (2) ◽  
pp. 248-255 ◽  
Author(s):  
R. J. Clifton ◽  
S. R. Bodner
Keyword(s):  
Pulse Propagation ◽  
Pure Aluminum ◽  
General Shape ◽  
Stress Strain ◽  
One Dimensional ◽  
Elastic Plastic ◽  
Strain Behavior ◽  
Commercially Pure ◽  
Strain Axis ◽  
The One

The one-dimensional, rate-independent theory of elastic-plastic wave propagation for smooth stress-strain curves concave toward the strain axis is applied to the problem of a long uniform bar loaded at one end by a pressure pulse of short duration. The essential features of the solution are obtained for the case of a semi-infinite bar and for the case of a finite bar whose other end is stress-free by using the method of characteristics in the t-x plane. The general shape of boundaries in the t-x plane which separate regions governed by the dynamic elastic equations from regions governed by the dynamic plastic equations is presented. The nature of the discontinuities that occur at these boundaries is also discussed. For the finite-bar case the analysis is given for materials which exhibit isotropic work hardening and for materials for which the stress-strain behavior in tension is independent of any previous compression. The main features of the solution are in agreement with the behavior observed for annealed, commercially pure aluminum bars subjected to explosive loading at one end. These experiments will be reported subsequently.

scholarly journals Influence of the form of axisymmetric load on the stress-strain state of an elastoplastic half-space

2019 ◽  
Vol 298 ◽  
pp. 00094
Author(s):  
Peter Ogar ◽  
Denis Gorokhov ◽  
Leonid Mamaev ◽  
Vladislav Kushnarev
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Half Space ◽  
Strain State ◽  
Stress Strain ◽  
Near Surface ◽  
Axisymmetric Load ◽  
Elastic Plastic ◽  
Stress Strain State

The problems of elastic sinking of materials and elastic restoration of an imprint under loading of an elastic-plastic half-space with an axisymmetric load of the form,P(r)=P0(1-r2/a2)β where 0<β<0.5 are considered. Expressions are obtained that describing the stress-strain state of an elastoplastic half-space. The conditions of the onset of plastic deformation in the near-surface layer and on the half-space of surface are considered depending on the parameter β.

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.

scholarly journals Effect of Plastic Deformation on Compliance Curve Based Crack Closure Measurement

2016 ◽  
Vol 713 ◽  
pp. 240-243
Author(s):  
M.A. Mohin ◽  
Y.G. Xu ◽  
A. Lewis ◽  
A. Chrysanthou
Keyword(s):  
Plastic Deformation ◽  
Crack Growth ◽  
Crack Closure ◽  
Complex Loading ◽  
Stress Strain ◽  
Crack Growth Behaviour ◽  
Strain Behavior ◽  
Compliance Curve ◽  
Crack Tip Plasticity ◽  
Potential Issue

Fatigue crack growth depends heavily on near tip stress-strain behavior controlled by many micromechanical and microstructural factors. Crack closure is widely used to rationalize crack growth behaviour under complex loading conditions. Reliable crack closure measurement is essential for enhanced damage tolerance design and remains a challenge to the industry. This paper focuses on the effect of plastic deformation ahead of a notch/crack on the non-linearity of compliance curves of 6082-T651 aluminium alloy specimens to highlight a potential issue in the conventional compliance curve based crack closure measurement technique. Experimental and numerical simulation results demonstrate that plastic deformation ahead of the notch will introduce non-linear stress-strain behavior in the absence of crack closure. It is proposed that the effect of crack tip plasticity on the non-linearity of the compliance curve be separated to obtain reliable crack closure measurement.

Microstructure transformation and stress-strain behavior of isotactic polypropylene under large plastic deformation

1997 ◽  
Vol 37 (10) ◽  
pp. 1702-1711 ◽  
Author(s):  
C. G'sell ◽  
V. Favier ◽  
J. M. Hiver ◽  
A. Dahoun ◽  
M. J. Philippe ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Isotactic Polypropylene ◽  
Large Plastic Deformation ◽  
Stress Strain ◽  
Strain Behavior ◽  
Microstructure Transformation
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