Postdoctoral Position for 12 months – Modeling the Viscoelastic Behavior of Foams under Large Cyclic Compressions and Dynamic Loading

This postdoctoral project aims to the viscoelastic behavior of polymeric foams under large deformations dynamic loadings. The objective is to simulate, using the finite element method, the response of these porous microstructures under complex loading conditions, including compression–relaxation tests and cyclic loading–unloading. A first stage will focus on analyzing the relationship between the viscoelastic properties...

F.E. simulations of closed-cells foams under extreme compression

The mechanical response of isotropic elastomeric closed-cell foams with Classical Voronoi microstructures is examined through three-dimensional finite element simulations. The study focuses on finite-strain uniaxial compression, complemented by infinitesimal-strain shear and hydrostatic loading. Random foam geometries with porosities between 77% and 95% and narrow pore-size distributions were generated by subtracting irregular Voronoi polyhedra, constructed from...

Helping PhD students to write their first paper

During the 2020 confinement as I was writting papers, I thought about making a 10 minutes black board video to explain my writting process to help students of our LMS lab to write their first paper. It seems to appeal students, so I give it a little bit more exposure here by sharing the link...

Homogenization jupyter notebook for students and professors teaching homogenization

During the COVID period, I supervised two Master’s students for three months, tasking them with developing an educational Jupyter notebook on homogenization. The notebook implements classic mean-field models, including Mori-Tanaka, self-consistent, generalized self-consistent, the four-phase model, Voigt, Reuss, and Hashin-Shtrikman bounds. Although I haven’t promoted it yet, I believe it could be highly beneficial to...

Microstamp: Stamps for DIC

We have been developping stamps to apply precise patterns on sample surfaces for local strain measurements using digital image correlation (DIC) during mechanical and thermal testing. Typically, when local strain measurements are needed in mechanical tests, sample surfaces are marked with spray paint or an airbrush to create a speckle pattern with good gray-level contrast....

Nonlinear behavior of a soft matrix highly filled with randomly spherical particle or voids

When highly reinforced a soft matrix, like an elastomer matrix, undergoes incredibly localized high strain where particles nearly touch. Therefore, it requires extensive remeshing efforts in an order to estimate numerically the equivalent homogeneous behavior of such a composite. We did that, using Abaqus *MAP SOLUTION option. This allowed to provide original numerical stress-strain responses...

Is it possible to characterize the linear viscoelasticity of an anisotropic carbon fibers reinforced thermoplastic polymer?

When dealing with isotropic polymer, it is easy to characterize the linear viscoelasticity in the lab via dynamic mechanic analysis in tension, torsion. What about for a transversely isotropic material such as a carbon fibers reinforced polymer? Actually, one may find out that it is not possible to directly assert any of the five parameters...

A finite strain viscoelastic model with damage and tension/compression asymmetry

In an effort to bring some clarification on the vast literature on finite strain viscoelastic models, initially defined for elastomers, a review of the pioneering models on finite strain viscoelastic from Le Tallec et al. (1993), Lion (1997) and Reese and Govindjee (1998) has shown that these models are totally equivalent [1]. It is not...

Comparison between two fracture tests, SENB vs. DCDC applied to acrylate polymers

We have compared the mode I opening critical energy release rate (GIc) measured using the single edge notch bending test and double cleavage drilled compression test on an elastic fragile PMMA and a bulk viscoplastic acrylate used as a glue for wind turbine blades. The study details the experimental procedure, for the crack initiation and...