Imperial College London
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DrEmilioMartinez-Paneda

Faculty of Engineering, Department of Civil and Environmental Engineering

Visiting Reader
 
 
 
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Contact

 

+44 (0)20 7594 8188e.martinez-paneda Website

 
 
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Location

 

249Skempton BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Shlyannikov:2021:10.1016/j.tafmec.2021.103128,
author = {Shlyannikov, V and Martínez-Pañeda, E and Tumanov, A and Khamidullin, R},
doi = {10.1016/j.tafmec.2021.103128},
journal = {Theoretical and Applied Fracture Mechanics},
pages = {1--15},
title = {Mode I and Mode II stress intensity factors and dislocation density behaviour in strain gradient plasticity},
url = {http://dx.doi.org/10.1016/j.tafmec.2021.103128},
volume = {116},
year = {2021}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - In this study, we use the mechanism-based strain gradient plasticity theory to evaluate both crack tip dislocation density behaviour and the coupled effect of the material plastic properties and the intrinsic material length on non-linear amplitude factors. The two planar classical stress-strain states are examined, namely, plane strain and plane stress, both under pure mode I and pure mode II loading conditions. The constitutive relations are based on Taylor's dislocation model, which enables gaining insights into the role of the increased dislocation density associated with large gradients in plastic strain near cracks. The material model is implemented in a commercial finite element (FE) software package using a user subroutine, and the nonlinear stress intensity factors (SIF) are evaluated as a function of the intrinsic material length, characterising the scale at which gradient effects become significant. As a result of the FE calculations of dislocation density distributions, the effects of both the fracture mode and the stress-strain state are determined. In pure mode I, the geometrically necessary dislocation (GND) density is located symmetrically with respect to the blunted crack tip. On the contrary, under pure mode II, the GND density becomes concentrated in the blunted and sharp parts of the crack tip. In this case, fracture initiation is shown to be likely to occur near the blunted region of the crack tip, where both the stress triaxiality and the GND density are at their maximum. The relation between the equilibrium state of dislocation densities and the intrinsic material length as well as the plastic SIF as a function of the work hardening exponent is discussed.
AU  - Shlyannikov,V
AU  - Martínez-Pañeda,E
AU  - Tumanov,A
AU  - Khamidullin,R
DO  - 10.1016/j.tafmec.2021.103128
EP  - 15
PY  - 2021///
SN  - 0167-8442
SP  - 1
TI  - Mode I and Mode II stress intensity factors and dislocation density behaviour in strain gradient plasticity
T2  - Theoretical and Applied Fracture Mechanics
UR  - http://dx.doi.org/10.1016/j.tafmec.2021.103128
UR  - http://arxiv.org/abs/2110.09211v1
UR  - https://www.sciencedirect.com/science/article/pii/S0167844221002299
UR  - http://hdl.handle.net/10044/1/92387
VL  - 116
ER  -
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