Evaluation of the fatigue defect population in an elastomer using X‐ray computed micro‐tomography

Abstract

AbstractAs elastomeric materials are heterogeneous by nature, their fatigue behavior is strongly driven by the initiation and the growth of cavities. In this study, X‐ray micro‐tomography is used to describe the fatigue mechanisms at a microscale. This non destructive method has already been widely applied to elastomeric materials to control the fillers size and dispersion or to analyze the cavitation induced under high hydrostatic pressure fatigue loading, for example. Here, this technique is used with a good resolution to analyze the evolution of the defects population during a fatigue campaign on hourglass shaped axisymmetric specimens. The initiation and propagation mechanisms are clearly shown on 3D observations, and the influences of the maximum principal strain and of the number of cycles on several parameters (size repartition, porosity, and defect volumic density) are investigated. A scenario for the fatigue damage evolution is proposed and some fatigue initiation criteria are finally discussed, using the results obtained at the microscopic scale. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers.