Experimental investigation of the stress-stretch behavior of EPDM rubber with loading rate effects

The tensile stress-stretch behavior of an ethylene-propylene-diene terpolymer (EPDM) was experimentally investigated, both in a quasi-static stretching rate range (<0.4/s) with a conventional material test machine and in a dynamic stretching rate range (2800/s-3200/s) with a split Hopkinson tension bar (SHTB) technique. Experimental data were then analyzed using the Ogden and Roxburgh's idealized Mullins effect modeling theory. Results show that the stress-stretch behavior is significantly dependent on stretching rate and the Mullins effect exists under dynamic loading. Furthermore, stretching rate only affects the material properties. The degree of damage in a stretched specimen is a function of only the maximum stretch ratio the specimen experienced. (C) 2003 Elsevier Ltd. All rights reserved.