International audienceThis paper reports on the development of a new network alteration theory to describe the Mullins effect. The stress-softening phenomenon that occurs in rubber-like materials during cyclic loading is analysed from a physical point of view. The Mullins effect is considered to be a consequence of the breakage of links inside the material. Both filler-matrix and chain interaction links are involved in the phenomenon. This new alteration theory is implemented by modifying the eight-chains constitutive equation of Arruda and Boyce (J. Mech. Phys. Solids 41 (2) (1993) 389). In the present method the parameters of the eight-chains model, denoted C-R and N in the bibliography, become functions of the maximum chain stretch ratio. The accuracy of the resulting constitutive equation is demonstrated on cyclic uniaxial experiments for both natural rubbers and synthetic elastomers

International audienceThe present paper deals with the fatigue crack growth in a carbon black filled cis-1,4-polyisoprene rubber under relaxing loading conditions. The study focuses on the determination of the scenario of crack growth. For this purpose, an original " microcutting " method is employed to observe microscopic phenomena involved in the growth of the crack with a SEM. It reveals that the cavitation induced by the decohesion between zinc oxides and rubber matrix is the major fatigue damage and that the crack tip is composed of stretched elliptical areas surrounded by highly stretched and crystallized ligaments. Finally, the observations are considered to establish the fatigue crack growth mechanism

This paper deals with the slamming phenomenon experienced by ships during impact between the bow and the water free surface. Slamming loads on ships may be sufficiently important to induce plastic deformation of the hull external structure. For extreme loading cases, they have been identified as the cause of ship loss. The problem to be solved is transient and highly nonlinear due to the complex water flow conditions. In the present paper, the three-dimensional Wagner problem is solved numerically using the finite element method. A numerical analysis is performed for both rigid and deformable structures. After this numerical analysis, an original experimental investigation is presented. It consists of a series of free fall drop-tests of rigid and deformable cone-shaped samples with different deadrise angles and thickness. Distribution and evolution of pressure are analyzed. Finally, our numerical results are successfully compared with experimental data. r