Franck Pastor

Limit Analysis and Macroscopic Strength of Porous Materials with Coulomb Matrix

The paper is devoted to the numerical Limit Analysis of a hollow spheroidal model with a Coulomb solid matrix. In a first part the hollow spheroid model is presented, together with its axisymmetric FEM discretization and its mechanical position. Then, after an adaptation of a previous static code, an original mixed (but fully kinematic) approach dedicated to the axisymmetric problem was elaborated with a specific quadratic velocity field associated to the triangular finite element. Despite the less good conditioning inherent to the axisymmetric modelization, the final conic mixed code appears very efficient, allowing to take into account numerical meshes highly refined. After a first validation in the case of spherical cavities and isotropic loadings, for which the exact solution is known, numerical bounds of the macroscopic strength are provided for both cases of spherical and spheroidal voids. Effects of the friction angle as well as that of the void aspect ratio are fully illustrated.