Experimental Investigation On The Tension Behavior Of Silicone Rubber

Due to their excellent resistance to temperature, oil, light and aging and good elastic properties, silicone rubbers are widely used as damping and buffering components in the vehicle, photoelectric instrument and aerospace industries. Such components maybe subjected to extreme loading conditions such as low and high temperatures and high speed impact. Therefore, it is important to investigate the effects of temperature and strain rate on the mechanical properties of silicone rubbers for engineering applications.To reveal the temperature effect on the tensile behavior of two filled silicone rubbers with Shore A hardness50(SR50) and80(SR80), quasi-static uniaxial tension tests were performed on the Instron testing machine over a wide range of temperatures from-50to50℃and automated grid method was used to accurately capture the full-field deformation information of the tension specimen. Experimental results indicate that the tension behavior of silicone rubber exhibits obvious nonlinear characteristics and temperature sensitivity. The value of modulus for SR80silicone rubber decreases with increasing temperature, while the value of modulus for SR50silicone rubber increases with the increase of temperature. The volume of silicone rubber changes little in the course of deformation at various testing temperatures, indicating that the silicone rubber can be regarded approximately as an incompressible material. Based on the measured tension stress-strain results, several commonly used hyperelastic constitutive models were evaluated. In order to accurately describe the nonlinear tension behavior of silicon rubbers within the small strain range, a modified Mooney-Rivlin model incorporating temperature effect was proposed. The model results agree well with the experimental data.To explore the strain-rate dependence of the tension behavior of silicone rubber, the effect of specimen geometry on the dynamic tension responses of silicone rubber was investigated. The strain calibration relations corresponding to different length-to-width ratio specimen was obtained. Based on the experimental investigation and numerical analysis, the suitable specimen size for high rate testing was determined. The high-rate uniaxial tension tests for SR80silicone rubber were carried out on the split Hopkinson tension bar system. Experiments reveal that the tension response exhibits apparent strain-rate strengthening characteristics.