computational homogenization

Dear colleagues,

Two fully-funded postdoctoral positions in computational mechanics of materials and structures are available in the groups of Milan Jirásek (https://mech.fsv.cvut.cz/~milan) and Jan Zeman (https://openmechanics.fsv.cvut.cz/people/jan-zeman). Full description of the openings is available at https://euraxess.ec.europa.eu/jobs/573988, the call closes on 5 December 2020.

Context
As part of a collaborative project between different Belgian industrial partners and Universities related to the study of composite laminate under impacts, the main objective of the doctoral position will be to develop a multi-scale numerical framework to study failure of the synthesized materials.

Professor Milan Jirásek at Faculty of Civil Engineering, Czech Technical University in Prague, is searching for a motivated Ph.D. student, who will work on our new ambitious project on non-periodic mechanical metamaterials. Candidates should be interested in and have some previous experience with mathematical modeling and numerical simulation of the mechanical response of materials and structures.

Since the beginning of the industrial age, material performance and design have been in the midst of innovation of many disruptive technologies. Today’s electronics, space, medical, transportation, and other industries are enriched by development, design and deployment of composite, heterogeneous and multifunctional materials. As a result, materials innovation is now considerably outpaced by other aspects from component design to product cycle. In this article, we review predictive nonlinear theories for multiscale modeling of heterogeneous materials.

A new perspective on model reduction for nonlinear multi-scale analysis of heterogeneous materials. In this work, we seek meaningful low-dimensional structures hidden in high-dimensional multi-scale data.

In our recent Extreme Mechanics Letter, we present a simulation consisting of 53.8 Billion finite elements with 28.1 Billion nonlinear equations that is solved on 393,216 computing cores (786,432 threads). The excellent parallel performance of the computational homogenization solver is demonstrated by a strong scaling test from 4,096 to 262,144 cores.

See attachement.

We've recently published an open access journal paper that looks at the mechanics of sutures used to repair severed tendons. A homogenization strategy is used to derive effective elastic properties for tendon fibrils and intracellular matrix. We have found that regions of high stress correlate with the regions of cell death (necrosis) that are sometimes observed in patients.

If this is of interest, please feel free to view the paper here.

Hello,

I read that "In general, even if the materials on the micro-level are isotropic, the effective 

material can show anisotropic behavior. A general anisotropic linear elastic material 

may have twenty one independent material parameters.''

If I understand my results correctly then simple structures like ''ball in the unit cell'' result in orthotropic material.

I am a bit puzzled - what would be the simplest structure that would result in anisotropic material behaviour?

Our Mechanics of Materials Group at Eindhoven University of Technology, the Netherlands has two openings for talented PhD students in the field of multiscale mechanics of materials. They are part of a European Union funded project on multiscale methods for advanced materials. One opening is on the development of a fundamentally new multiscale approach towards material modelling and the other aims to integrate this approach with experimental methods.

You are welcome to submit abstracts to the MS 4.5 "Multiscale Computational homogenization for bridging scales in the mechanics and physics of complex materials", organized by P. Wriggers, K. Terada, V. Kouznetsova, M. Cho and myself at the 12th US National Congress on Computation Mechanics (USNCCM), July 22-25, 2013, in Raleigh, USA.

http://12.usnccm.org/

The  deadline fo abstract submission is February 15, 2013.

The topics of the MS can be found here:

Several methods have been proposed for numerical homogeniation of linear viscoelastic materials, mainly based on Laplace transform or on multilevel (FE^2) approaches. In this paper, we introduce a much simpler technique based on a discrete representation of the effective relaxation tensor related to the homogeneous medium, which can then be used to evaluate the constitutive law in the form of a convolution product. In practice, calculations on the RVE reduce to 3 transient simulations in 2D and 6  in 3D. More details in