Multiaxial failure of dual-phase elastomeric composites

The natural rubber (NR) and styrene butadiene rubber (SBR) based composites are used in several industrial applications, mainly tires. The mechanical properties can be tailored by blending them in appropriate ratios. In the present study, blended polymer-matrix composites are tested for uniaxial and bulge tests. Simultaneous constitutive modeling with failure description is done for uniaxial and equibiaxial test results. Using the computational modeling we study the problem of cavitation and compare these results with morphological analysis. The finite element analysis (FEA) is used to analyze state of stress throughout the bulge. We find that the rubber composites can behave contradictorily under different types of mechanical testing environments. For instance, the pressure at failure for SBR composite is found to be 3% more than NR composite under bulge test. However, tensile strength of NR composite is found to 40% more than that of SBR composite, when tested uniaxially. The critical hydrostatic tension corresponding to onset of cavitation is observed to decreasing by more than 20% when NR composite is compared with SBR composite. The dual phase rubber composite with 25% NR and 75% SBR exhibits better mechanical properties, when compared with other blended composites.