Biaxial fatigue behavior of a polychloroprene rubber

Understanding phenomenon induced by complex fatigue loadings is an important issue for the conception of industrial components. Rubber materials, thanks to their abilities to withstand high deformations, are more and more used in industry. In an ongoing study, an experimental investigation is being carried out to study the effect of multiaxial loadings on the fatigue life of polychloroprene rubber. This material is used for pulleys. Specimen used is a dumbbell type, axisymetric geometry with a reduced section at mid-height. The experimental results indicate that under uniaxial tensile loading a kink in the conventional Haigh diagrams is observed leading to high lives at high R-ratio loading as compared to low R-ratios. Fractographic studies indicate the presence of crystallographic tongues under high R-ratio loading. To reproduce multiaxial conditions on this specimen, combined axial displacements and torsion rotation fatigue tests are performed, according to three different paths, depending on the phase angle between the two axes. Different multiaxial fatigue criteria are used to analyze experimental results.