Category: Current projects

Together with my student Damien Ollion, we have converted the finite-strain viscoelastic UMAT originally developed with Florian Gouhier into a VUMAT for Abaqus/Explicit. The implementation reproduces the constitutive model of Reese and Govindjee (1998) for a generalized Maxwell model and includes the following features: A comprehensive How-to-use.pdf document is provided. It presents the constitutive equations, illustrates the...

Following our previous investigation of the beahvior of hyperelastic classic Voronoi closed-cell foams submitted to severe compression, we have extended the study to assess the influence of microstructure on the mechanical response of highly porous foams. To this end, two additional classes of microstructures were generated: mechanically grown Voronoi (M-Voro) closed-cell foams and open-cell foams...

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...

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....