research

http://dx.doi.org/10.1080/14786435.2019.1582850

Abstract

Published in Physcal Review Letters: https://doi.org/10.1103/PhysRevLett.122.045502. Many materials are anisotropic. However, there is no widely accepted measure for characterizing the degree of elastic anisotropy. Here, assuming that the limiting case of extreme anisotropy should possess a positive semidefinite stiffness matrix, we propose three criteria to evaluate measures of anisotropy and show that the existing measures in the literature do not satisfy all of the proposed criteria.

https://doi.org/10.1002/adma.201805665 Computational modeling and simulations play an integral role in the bottom‐up design and characterization of graph‐n‐yne materials. Here, the state of the art in modeling α‐, β‐, γ‐, δ‐, and 6,6,12‐graphyne nanosheets for synthesizing graph‐2‐yne materials and 3D architectures thereof is discussed. Different synthesis methods are described and a broad overview of computational characterizations of graph‐n‐yne's electrical, chemical, and thermal properties is provided.

https://doi.org/10.1038/s41467-019-08813-x We report a transfer approach using paraffin as a support layer, whose thermal properties, low chemical reactivity and non-covalent affinity to graphene enable transfer of wrinkle-reduced and clean large-area graphene.

We are looking for a candidate with a Ph.D. degree to study fracture problems in bimetallic pipelines,  API X65 internally clad with alloy 625. The project has direct application to offshore exploration in Brazil deepwater fields. The project is going to be funded by the Petrobras company. The chosen candidate will develop a parametric model to model the welded joint of this type of pipes using python/Abaqus, being the numerical model as close as possible to the real geometry.

We have published a paper called "Micromechanical model for prediction of the fatigue limit for unidirectional fibre composites" in Mechanics of Materials. See the link here.

I hope some of you will find our recent paper in the Journal of the Mechanics and Physics of Solids interesting. The Abaqus user element (UEL) subroutine developed to implement strain gradient plasticity theories with energetic and dissipative higher order stresses (Gudmundson 2004, Fleck and Willis 2009) can be downloaded from www.empaneda.com/codes

The role of plastic strain gradients in the crack growth resistance of metals

Emilio Martínez-Pañeda, Vikram S. Deshpande, Christian F. Niordson, Norman A. Fleck

Published in Phys. Rev. B: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.97.184305

Published in Nanoscale and Microscale Thermophysical Engineering: https://www.tandfonline.com/doi/full/10.1080/15567265.2019.1576816

Wenjie Xia, Xin Qin, Yao Zhang, Rober Sinko, Sinan Keten

Macromolecules (2018), https://pubs.acs.org/doi/abs/10.1021/acs.macromol.8b02243