TY - THES

T1 - Characterization of Rapid Gas Decompression Behavior of Pressurized Elastomer Seals

AU - Lederer, Klaus

N1 - embargoed until null

PY - 2006

Y1 - 2006

N2 - A phenomenon termed explosive decompression (ED) damage occurs when elastomer seals exposed to high gas pressure fail in a brittle manner upon the sudden release of the gas pressure. The main objective of this thesis was the development and implementation of adequate test methods to characterize the explosive decompression failure resistance of elastomers. Therefore a comprehensive testing methodology was developed. Tests using two different elastomers FKM (Fluorocarbon Rubber) and HNBR (Hydrogenated Nitrile Butadiene Rubber) were performed on a component as well as on a specimen level. A main goal was the implementation of fully instrumented autoclave tests using commercially available O-rings. These tests allowed to gain insight into the mechanisms and kinetics of the explosive decompression failure as functions of material expansion, pressure and temperature were recorded. In addition to instrumented ED tests, a comprehensive parameter test series was performed. Investigated parameters were the ambient gas, test temperature, pressure, decompression rate, O-ring constraints and the influence of multi-cycle loading. On specimen level, a specially developed test set-up using dumbbell specimens allowed the examination of various elements of the explosive decompression process. Apart from that, monotonic tensile tests with pre-cracked FWPS specimens were performed. The tests were analyzed with help of full-field strain analysis and IR-thermograph test systems.

AB - A phenomenon termed explosive decompression (ED) damage occurs when elastomer seals exposed to high gas pressure fail in a brittle manner upon the sudden release of the gas pressure. The main objective of this thesis was the development and implementation of adequate test methods to characterize the explosive decompression failure resistance of elastomers. Therefore a comprehensive testing methodology was developed. Tests using two different elastomers FKM (Fluorocarbon Rubber) and HNBR (Hydrogenated Nitrile Butadiene Rubber) were performed on a component as well as on a specimen level. A main goal was the implementation of fully instrumented autoclave tests using commercially available O-rings. These tests allowed to gain insight into the mechanisms and kinetics of the explosive decompression failure as functions of material expansion, pressure and temperature were recorded. In addition to instrumented ED tests, a comprehensive parameter test series was performed. Investigated parameters were the ambient gas, test temperature, pressure, decompression rate, O-ring constraints and the influence of multi-cycle loading. On specimen level, a specially developed test set-up using dumbbell specimens allowed the examination of various elements of the explosive decompression process. Apart from that, monotonic tensile tests with pre-cracked FWPS specimens were performed. The tests were analyzed with help of full-field strain analysis and IR-thermograph test systems.

KW - Rapid Gas Decompression Explosive Decompression FKM HNBR Fluorocarbon Rubber Hydrogenated Nitrile Butadiene Rubber Autoclave tests

KW - Explosive Dekompression FKM HNBR Elastomer

M3 - Diploma Thesis

ER -