The Influence of Sample Size on the Tear Strength Measurement of Silicone Rubber Composite for Electrical Insulation

Composite insulators have been widely adopted due to their excellent overall performance. However, complex service environments can lead to the aging of silicone rubber (SR), significantly affecting its long-term performance. Tear strength is a critical indicator for assessing the degree of SR aging, but earlier research has often imposed stringent requirements on sample dimensions. In this study, five different sample sizes for two typical types of SR used in composite insulators were tested to evaluate differences in tear strength. Subsequently, these differences were analyzed in conjunction with stress-strain curves. Finally, numerical fitting was employed to investigate the correlation between tear strength and sample dimensions. The results indicate that, for both types of SR, tear strength shows an approximately proportional relationship to sample dimensions, and the proportionality constant depends on the material.