Please use this identifier to cite or link to this item: https://doi.org/10.15480/882.1364
Publisher DOI: https://doi.org/10.3390/ma10030289
Title: The role of geometrically necessary dislocations in cantilever beam bending experiments of single crystals
Language: English
Authors: Husser, Edgar 
Bargmann, Swantje 
Keywords: cantilever beam bending;size effect;geometrically necessary dislocations;crystal plasticity;finite element method
Issue Date: 16-Mar-2017
Source: Husser, E.; Bargmann, S. The Role of Geometrically Necessary Dislocations in Cantilever Beam Bending Experiments of Single Crystals. Materials 2017, 10, 289.
Journal or Series Name: Materials 
Abstract (english): The mechanical behavior of single crystalline, micro-sized copper is investigated in the context of cantilever beam bending experiments. Particular focus is on the role of geometrically necessary dislocations (GNDs) during bending-dominated load conditions and their impact on the characteristic bending size effect. Three different sample sizes are considered in this work with main variation in thickness. A gradient extended crystal plasticity model is presented and applied in a three-dimensional finite-element (FE) framework considering slip system-based edge and screw components of the dislocation density vector. The underlying mathematical model contains non-standard evolution equations for GNDs, crystal-specific interaction relations, and higher-order boundary conditions. Moreover, two element formulations are examined and compared with respect to size-independent as well as size-dependent bending behavior. The first formulation is based on a linear interpolation of the displacement and the GND density field together with a full integration scheme whereas the second is based on a mixed interpolation scheme. While the GND density fields are treated equivalently, the displacement field is interpolated quadratically in combination with a reduced integration scheme. Computational results indicate that GND storage in small cantilever beams strongly influences the evolution of statistically stored dislocations (SSDs) and, hence, the distribution of the total dislocation density. As a particular example, the mechanical bending behavior in the case of a physically motivated limitation of GND storage is studied. The resulting impact on the mechanical bending response as well as on the predicted size effect is analyzed. Obtained results are discussed and related to experimental findings from the literature.
URI: http://tubdok.tub.tuhh.de/handle/11420/1367
DOI: 10.15480/882.1364
Institute: Kontinuums- und Werkstoffmechanik M-15 
Type: (wissenschaftlicher) Artikel
Project: Open Access Publizieren 2016 - 2017 / Technische Universität Hamburg-Harburg 
Appears in Collections:Publications (tub.dok)

Files in This Item:
File Description SizeFormat
Husser_Bargmann_MATERIALS_2017.pdf6,41 MBAdobe PDFThumbnail
View/Open
Show full item record

Page view(s)

220
Last Week
2
Last month
12
checked on Jul 24, 2019

Download(s)

301
checked on Jul 24, 2019

Google ScholarTM

Check

Export

This item is licensed under a Creative Commons License Creative Commons