Strain and damage monitoring in SBR nanocomposites under cyclic loading

In the present work a comparative study of the piezoresistivity behavior of two series of elastomeric nanocomposites, based on Styrene-Butadiene Rubber (SBR), reinforced with carbon black (CB) and carbon nanotubes (CNTs) has been performed. The relative resistance change with strain was recorded under monotonic and cyclic testing, revealing different response between CB and CNTs. The piezoresistivity response was more repeatable for the elastomeric nanocomposites which have been previously deformed and relaxed under zero stress. Moreover, the strain softening behavior of the materials under loading-unloading was examined by employing a rubber-softening empirical model developed in previous works.