Study On Fatigue Life And Durability Of Rubber Vibration Isolation Pad

With the rapid development of rail transportation, more and more attention are being paid to the service life of rubber vibration isolation pad from orbit design and construction personnel. The rubber vibration isolation pad is used in high-speed railway, subway, rail and the viaduct, because of the complex work environment,long-term compression and different frequency vibration and fatigue failure by train also by all the effects of aging, its service life is limited. Due to the characteristics of the rail transit is inconvenient for outage maintenance, it is expected that the service life of the rubber vibration isolation pad is longer and better, so as to reduce the inconvenience and cost consumption caused by the maintenance or replacement. At present, the research on the service life of rubber vibration isolation pad is still in the exploratory stage. Therefore, it has very important significance and practical value to predict the fatigue life of vibration isolation pad, and study its durability.In this paper, the effect of water immersion on the properties of rubber isolation pad damping layer was studied, and the service life of the vibration isolation pad under the full or empty load condition was predicted by accelerated aging test; On the basis of the original formula, through the use of rubber, adjusted the curing system and the protection system and other methods to optimize the formula, so as to further improve the fatigue resistance and aging resistance of the vibration isolation pad.Studied the properties change of damping layer blend soaked in different temperature water with different time, the results showed that: At lower temperature,the effect of water immersion on the mechanical properties and static stiffness of the damping layer was very small; With the increase of the water temperature and the soaking time, the mechanical properties decreased, the static stiffness and the compression permanent deformation increased, and the compressive creep variables increased, demonstrated the effect of temperature on the properties of damping layer is greater than that of water.Ignored the effect of water and vibration on the vibration isolation pad performance, used the standard of GB/T 20028, the life of rubber isolation pad products were predicted under different condition, the results showed that: The servicelife of rubber vibration isolation pad was about 7.3 years under the condition of 24 h uninterrupted full load, storage life is 35.3 years. The prediction results had high confidence level, indicated that the use of accelerated aging method, using the Arrhenius equation to predict the service life of rubber vibration isolator is feasible.In the experiment, blended NR with TPI, and studied the effect of mixing technology, the use ratio, the content of sulfur and fantioxidant on the fatigue resistance, aging resistance and static stiffness of rubber isolation pad damping layer.The results showed that: on the basis of original formulation, with 20 phr TPI replaced NR, the flexing fatigue life extended more than doubled, creep resistance improved,the static and dynamic stiffness ratio decreased by 3.8%, tan delta values above 60 centigrade declined, but the aging resistance declined; And used 20 phr TPI, adjusted the amount of sulfur at 2.3 phr, the antioxidant content at 2.5 phr, the aging resistance of the damping layer improved under meeting the mechanical property requirements for the foundation. On the whole, the optimization formula improved the durability of the rubber vibration isolation pad.