Hyperelastic Constitutive Model Determination and Structural Optimization Based on High Vacuum Elastomer Sealing Structure

Abstract

The stress analysis of rubber liner is widely used in the design of high vacuum elastomer sealing structure. It is very important to determine a reasonable constitutive model and establish a strength evaluation method suitable for failure mode. A series of mechanical properties tests of JY7766 fluororubber were completed in this paper, and material parameters under different constitutive models and strain levels were fitted. A model selection method based on stiffness relative deviation of liner as evaluation index was proposed, and the high precision constitutive model and material parameters with only 0.2% stiffness relative deviation was determined. At the same time, the consistency of crack propagation path and Mises stress distribution of liner was confirmed based on the comparison between theoretical calculation and the actual structure. Under the condition of ensuring the contact total stress of main sealing surface, the maximum Mises stress was reduced by 43.6% and the safety margin of structural strength was improved by optimizing the sealing groove size of a vacuum equipment. The test result showed that the optimized structure meet the requirement of sealing performance.