Study of Plastic Deformation Behavior of Metal Seals

• Main Authors: Jia-Yuan Sheu, 許嘉元
• Other Authors: Jung-Ho Chen
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/28983073858549778240

碩士 === 國立臺灣大學 === 機械工程學研究所 === 88 === Because of the advantages of low gas leakage and heat durability of the metal gasket sealing technology, it’s been applied in gas distribution system which requires ultra-high vacuum. The leakage of metal gasket sealing results from the contact of asperity on the surface of material and the deformation of this asperity influences the leakage. The research of the metal gasket sealing technology is limited when force is taken into account as a parameter in the experiment of leakage curve and it results in the increase of the cost and the decrease of efficiency when asked for the improved or new design. Secondly, it still exists certain difficulties and suitability to simulate the deformation of asperity and the leaking behavior of micro-channel. This research is to observe the process of the deformation of asperity on the surface and establish its hypothesis for the goal to setup a leakage prediction model with deformation as a key factor. Experiment on one gasket sealing with specific surface roughness and finite element analysis in responding to the experimental conditions, along with the simulation of smooth-surface materials and the maximum equivalent plastic strain on the surface as the index of asperity deformation, determine the key factor of the gas leakage. With the combination of the results of the experiments and the analysis, we can build up a leakage prediction model based on the maximum equivalent plastic strain on the surface and the gas leakage, and successfully apply to other gasket seals. This model is capable of applying to various gasket seal of one specific roughness. It not only expands the application range for the gasket experiment, but also adapts the combination of every material. With the speedy computer analysis, we can obtain the change of the leakage through the leakage prediction model, when faced different designs. Moreover, taking advantage of the process in the study, it is possible to develop more leakage prediction curves with various kinds of surface roughness.