Study of the static airtightness mechanisms of metal seals
Description
The thesis aims to better understand the sealing mechanisms in contact at the interface between a metal gasket and clamps. The proposed approach is based on the development of a numerical model of the clamping seal by incorporating the laws' behavior of materials that will be determined by micro instrumented indentation testing. This model is particularly interested in identifying ways of providing the fluid leak to be sealed and to determine leakage rates resulting from the identified paths, as well as the evolution of the conductance of the interface over time. Particular attention will be paid to the roughness of the surfaces, changing leak paths at different levels depending on the tightening of the seal and gas flow rates in the different types of defects. The study was conducted in Pierrelatte's Sealing laboratory that develops metal seals for the aerospace, nuclear and scientific research. The thesis focuses on real surfaces and was supplemented by measurements of helium leaks using a press which applies different loads at different gas pressures and different roughness. (author)
Abstract (French)
La these vise a mieux comprendre les mecanismes de l'etancheite dans un contact, a l'interface entre un joint metallique et des brides de serrage usinees en tournage ayant differentes rugosites. L'approche proposee repose en partie sur le developpement d'un modele numerique du serrage du joint en integrant les lois de comportement des materiaux qui sont determinees dans un premier temps par des essais de traction, puis par micro-indentation instrumentee dans un second temps. Ce modele s'interessera en particulier a determiner les chemins de fuite s'offrant au fluide a etancher et a determiner les debits de fuite decoulant des chemins identifies, ainsi que l'evolution de la conductance de l'interface au cours du temps. Une attention particuliere sera accordee a la rugosite des surfaces, a l'evolution des chemins de fuite aux differentes echelles en fonction du serrage du joint et aux debits de gaz dans les differents types de defauts. L'etude est realisee au sein du Laboratoire d'Etancheite de Pierrelatte qui developpe des joints metalliques pour l'aerospatiale, le nucleaire et la recherche scientifique. La these s'interesse a des surfaces reelles et a ete completee par des mesures de fuites d'helium sous presse en fonction de la charge appliquee, a differentes pressions et differentes rugosites
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Additional details
Additional titles
- Original title (French)
- Mecanismes de l'etancheite statique des joints metalliques
Identifiers
Publishing Information
- Imprint Pagination
- 192 p.
- Report number
- FRCEA-TH--5696
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 45089404
- Subject category
- S36: MATERIALS SCIENCE;
- Resource subtype / Literary indicator
- Thesis
- Descriptors DEI
- ALUMINIUM; COMPUTERIZED SIMULATION; ELASTICITY; FRICTION; GASKETS; HARDENING; HELIUM; INTERFACES; LEAKS; PLASTICITY; ROUGHNESS; SEALING MATERIALS
- Descriptors DEC
- ELEMENTS; FLUIDS; GASES; MATERIALS; MECHANICAL PROPERTIES; METALS; NONMETALS; RARE GASES; SEALS; SIMULATION; SURFACE PROPERTIES
Optional Information
- Notes
- [80 refs.]; Available from the INIS Liaison Officer for France, see the 'INIS contacts' section of the INIS-NKM website for current contact and E-mail addresses: http://www.iaea.org/inis/Contacts/, Also available from Service Commun de l'Information et de la Documentation de l'Ecole des Mines, Ecole Nationale Superieure des Mines de Saint-etienne, 158, cours Fauriel, CS 62362 42023 Saint-Etienne (France)