The Preliminary Fatigue Discussion Of Bi-Block Ballastless Track Slab

In our country,the design of ballastless track usually don't consider the influence of the structure fatigue. Actually,the ballastless track slab structure bears the cycle force influence,such as vertical force from the wheel,bending stress from the temperature and so on.It is possible that the slab will occurs fatigue destroy during it's using age.So,it has an important Significance to research the fatigue damage and life of the slab.In this paper,Two Rheda 2000 ballastless track slab modles are created.with different thickness. One of them is 240mm,and the other is 300mm. Through the modles the slab's fatigue life is Preliminary discussed and studied by the finite element method. The paper first introduced the slab's fatigue cumulative damage theory and damage detection method.Then ,by the the experience method of S—N curves,the slab's fatigue life is preliminary estimated and analyzed under following three conditions:1.Under the condition of heave haul freight line, the train pass through the slab with three different speed rates,that is 80km/h,100km/h,and 120km/h.2.Under the condition of Passenger Dedicated Line transport, the train pass through the slab with two different speed rates ,that is 200km/h and 250km/h.3.Under the condition of the temperature bending stress.Basing on the calculating, fatigue life's cloud pictures about the slabs are generated under these different conditions.Then the area of fatigue destroy and the reason for the destroy is analysised. At last the fatigue destroy degree of the two different thickness slab is compared under the same stress cycle times.