Effect of Loading Rate on the Ultimate Tensile Strength of a Soft Polydimethylsiloxane

This study investigates the effect of loading rate on the ultimate tensile strength of a commercial soft polydimethylsiloxane. Uniaxial tensile tests were performed at 10, 50, 100, and 1000 mm/min, and the results were analyzed using non-parametric statistical methods. The Kruskal–Wallis test revealed a significant effect of loading rate on UTS (p < 0.0001), with the mean strength increasing from 1.240 MPa at 10 mm/min to 1.927 MPa at 1000 mm/min. Post hoc analysis showed that the tensile strength at 1000 mm/min was significantly higher than at all lower rates, while no significant differences were found among the 10, 50, and 100 mm/min groups. These findings provide a statistically validated dataset that supports the design and reliability assessment of soft devices operating under dynamic loading conditions.