The Effect of Oil Swelling on the Fatigue Life of Elastomers subjected to Cyclic Bubble Inflation

Niall Murphy, Dublin Institute of Technology
John Hanley, Dublin Institute of Technology
Stephen Jerrams, Dublin Institute of Technology
Ali Hassan, Dublin Institute of Technology

Presented at the ISE 2007, September 23 - 27, Frieburg, Germany


This paper describes the behaviour of rubber in multi-axial fatigue, with respect to oil resistance. A series of tests were carried out on EPDM specimens subjected to varying degrees of swelling. The control methodology and the loading mechanism employed in the testing of elastomers using dynamic multi-axial bubble inflation are outlined. Swollen specimens were prepared by immersing them in reference mineral oil. Specimens were cycled to failure and the results were analysed. The number of cycles to failure for a given engineering stress amplitude was plotted for both dry (unswollen) and swollen specimens. Fracture surfaces for each set of specimens were analysed. The effect of swelling on the stress-strain behaviour and the change in complex modulus for each specimen set is discussed.