Fatigue life of rubber components: 3D damage evolution from X-ray computed microtomography

Coupled to monotonic, uniaxial and multiaxial fatigue tests, μCT observations provide a new and complete description in three dimensions of how cracks initiate and propagate as a function of loading and fatigue cycles. With help of image analysis tools, number and size 3D repartitions of inclusions are quantified with a high spatial resolution of 5 microns. 3D repartition in distance between inclusions is also determined allowing the analysis of different damage processes in the case of isolated inclusion and in the case of inclusions in close proximity along the loading direction. Those results are interpreted in terms of calculated stress repartition analysis around inclusions. From real 3D observations, damage evolution is analysed and clearly demonstrates the different failure phenomena including debonding, cavitation and coalescence. In this way, interconnections are established between mechanical tests results at a macroscopic scale and intrinsic material description at a microscopic scale.