A new design concept of metal O-ring seal for long-term performance

• It is required to increase the elastic recovery for long time operation.
• The elastic energy is additionally considered as a comparison target.
• The stored elastic energy as well as the elastic recovery can be significantly improved.
• The protrusions appear on the inner boundary of upper and lower portions.
• The elastic stress distribution appears like an annular band in the middle of the thickness.

Elastic recovery is one of the major elements determining sealing performance of the metal seal. Therefore, it is required to increase the elastic recovery for long time operation in extreme environments i.e. high temperature, radiation dose.This paper presents how much elastic recovery can be improved by optimizing the design of the metal O-ring seal without any aids such as an Inconel spring. The shape optimization has been performed based on the result from the topology optimization of the previous study. In order to determine its shape for high elasticity, the cubic B-spline was used and the real coded genetic algorithm (RCGA) was adopted as an optimization algorithm. This study was accompanied with the elasto-plastic analysis to calculate major parameters for performance estimation. Lastly, the elastic recovery and the stored elastic energy rate on the final optimal shape were compared to that of the typical metal O-ring seal.