On energetic and dissipative gradient effects within higher-order strain gradient plasticity: Size effect, passivation effect, and Bauschinger effect

2021 ◽  
pp. 102994
Author(s):  
Fenfei Hua ◽  
Dabiao Liu ◽  
Yuan Li ◽  
Yuming He ◽  
D.J. Dunstan
Keyword(s):  
Size Effect ◽  
Strain Gradient ◽  
Bauschinger Effect ◽  
Higher Order ◽  
Strain Gradient Plasticity ◽  
Gradient Plasticity ◽  
Gradient Effects

Novel analysis for nanoindentation size effect using strain gradient plasticity

2005 ◽  
Vol 53 (10) ◽  
pp. 1135-1139 ◽  
Author(s):  
Hunkee Lee ◽  
Seonghyun Ko ◽  
Junsoo Han ◽  
Hyunchul Park ◽  
Woonbong Hwang
Keyword(s):  
Size Effect ◽  
Strain Gradient ◽  
Strain Gradient Plasticity ◽  
Gradient Plasticity

On the fracture of small samples under higher order strain gradient plasticity

2014 ◽  
Vol 187 (2) ◽  
pp. 213-226 ◽  
Author(s):  
Suman Guha ◽  
Sandeep Sangal ◽  
Sumit Basu
Keyword(s):  
Strain Gradient ◽  
Higher Order ◽  
Strain Gradient Plasticity ◽  
Small Samples ◽  
Gradient Plasticity

scholarly journals A potential for higher-order phenomenological strain gradient plasticity to predict reliable response under non-proportional loading

2019 ◽  
Vol 475 (2229) ◽  
pp. 20190258 ◽  
Author(s):  
Andrea Panteghini ◽  
Lorenzo Bardella ◽  
Christian F. Niordson
Keyword(s):  
Strain Gradient ◽  
Free Energy Density ◽  
Higher Order ◽  
Strain Gradient Plasticity ◽  
Threshold Values ◽  
Gradient Plasticity ◽  
Proportional Loading ◽  
Size Dependent ◽  
Plastic Potential ◽  
Dislocation Density Tensor

We propose a plastic potential for higher-order (HO) phenomenological strain gradient plasticity (SGP), predicting reliable size-dependent response for general loading histories. By constructing the free energy density as a sum of quadratic plastic strain gradient contributions that each transitions into linear terms at different threshold values, we show that we can predict the expected micron-scale behaviour, including increase of strain hardening and strengthening-like behaviour with diminishing size. Furthermore, the anomalous behaviour predicted by most HO theories under non-proportional loading is avoided. Though we demonstrate our findings on the basis of Gurtin (Gurtin 2004 J. Mech. Phys. Solids 52 , 2545–2568, doi:10.1016/j.jmps.2003.11.002 ) distortion gradient plasticity, adopting Nye's dislocation density tensor as primal HO variable, we expect our results to hold qualitatively for any HO SGP theory, including crystal plasticity.

Experimental Evaluation and Modeling Analysis of Micromilling of Hardened H13 Tool Steels

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Hongtao Ding ◽  
Ninggang Shen ◽  
Yung C. Shin
Keyword(s):  
Tool Wear ◽  
Size Effect ◽  
Strain Gradient ◽  
Chip Formation ◽  
Experimental Evaluation ◽  
Strain Gradient Plasticity ◽  
Fe Model ◽  
Tool Steels ◽  
Gradient Plasticity ◽  
Continuous Chip

This study is focused on experimental evaluation and numerical modeling of micromilling of hardened H13 tool steels. Multiple tool wear tests are performed in a microside cutting condition with 100 μm diameter endmills. The machined surface integrity, part dimension control, size effect, and tool wear progression in micromachining of hardened tool steels are experimentally investigated. A strain gradient plasticity model is developed for micromachining of hardened H13 tool steel. Novel 2D finite element (FE) models are developed in software ABAQUS to simulate the continuous chip formation with varying chip thickness in complete micromilling cycles under two configurations: microslotting and microside cutting. The steady-state cutting temperature is investigated by a heat transfer analysis of multi micromilling cycles. The FE model with the material strain gradient plasticity is validated by comparing the model predictions of the specific cutting forces with the measured data. The FE model results are discussed in chip formation, stress, temperature, and velocity fields to great details. It is shown that the developed FE model is capable of modeling a continuous chip formation in a complete micromilling cycle, including the size effect. It is also shown that the built-up edge in micromachining can be predicted with the FE model.

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