Study of the Effects of Gamma Irradiation on the Mechanical Properties of NBR Material

This article presents an experimental study of the mechanical properties of nitrile-butadiene rubber (NBR) when irradiated with gamma rays. NBR was irradiated with gamma rays at different absorbed radiation energy doses (0, 30, 45, 60, 75 and 90 kGy). Tensile experiments and hardness test analyses show an improvement in the elastic behavior of NBRs and a decrease in their plastic behavior with increasing absorbed radiation energy doses. Scanning electron microscopy (SEM) shows the NBR surface layer to be porous and cracked as a result of gamma irradiation. The experimental study was completed by a numerical simulation with Abaqus software using hyperelastic models (Mooney Rivlin model, Ogden model, Yeoh model, Arruda-Boyce model and Neo-Hookean model). The simulation uses input data obtained from traction results. Curves of stress-strain for pristine and irradiated samples, obtained from numerical and experimental studies, were compared. Parameters of the hyperelastic deformation energy function are computed for each of the five models. So, the Ogden model was found to produce the most accurate curve, with a mean square error less than 0.5%. The Ogden model is therefore the most appropriate for simulating the mechanical behavior of irradiated nitrile-butadiene rubber. The results obtained provide a good basis for describing the performance of this material under gamma rays.