Strain rate, temperature and deformation state effect on Ecoflex 00-50 silicone mechanical behaviour

Abstract

Silicone elastomers are extremely attractive materials due to their wide range of possible applications, from biomedical engineering to soft robotics. In this work, an extensive thermo-mechanical characterization of Ecoflex Shore hardness 00–50, a commercially available silicone elastomer, has been carried out to compensate for the lack of relevant literature. The mechanical behaviour of the material has been characterized by performing monotonic and cyclic loading tests. These tests were performed in different deformation states, i.e. uniaxial tension, pure shear and biaxial tension, at different strain rates and temperatures. Experimental findings allowed to highlight the material time-dependent response and quantify the contribution of dissipative deformation phenomena to the overall strain energy. Uniaxial tensile tests performed at different temperatures (between −40 °C and 140 °C) showed that the material mechanical behaviour is sensitive to temperature in this range: a decrease of the ultimate stress and strain has been observed with increasing temperature. Finally, the data obtained from the latter tests have been used to define a failure envelope, applied for the first time to Ecoflex silicones, and valuable to describe the material ultimate stress and strain at any temperature and strain rate.