American Institute of Aeronautics and Astronautics 1 Paper for the Special Session on Nanostructured Materials at the 50 th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics and Materials Conference and Exhibit A Continuum-Atomistic Analysis of Transgranular Crack Propagation in Aluminum V. Yamakov * , E. Saether † , and E. Glaessgen ‡ NASA Langley Research Center, Hampton, VA, 23681 Abstract A concurrent multiscale modeling methodology that embeds a molecular dynamics (MD) region within a finite element (FEM) domain is used to study plastic processes at a crack tip in a single crystal of aluminum. The case of mode I loading is studied. A transition from deformation twinning to full dislocation emission from the crack tip is found when the crack plane is rotated around the [ ] crystallographic axis. When the crack plane normal coincides with the [112] twinning direction, the crack propagates through a twinning mechanism. When the crack plane normal coincides with the [011] slip direction, the crack propagates through the emission of full dislocations. In intermediate orientations, a transition from full dislocation emission to twinning is found to occur with an increase in the stress intensity at the crack tip. This finding confirms the suggestion that the very high strain rates, inherently present in MD simulations, which produce higher stress intensities at the crack tip, over-predict the tendency for deformation twinning compared to experiments. The present study, therefore, aims to develop a more realistic and accurate predictive modeling of fracture processes. * National Institute of Aerospace. † Durability, Damage Tolerance, and Reliability Branch, MS/188E, AIAA Member. ‡ Durability, Damage Tolerance, and Reliability Branch, MS/188E, AIAA Associate Fellow.
A Continuum-Atomistic Analysis of Transgranular Crack Propagation in Aluminum
May 21, 2023
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Related Documents
