Study On The Fatigue Property Of6061Aluminum Alloy Treated By Local Plastic Deformation

With the development of industrial technology. Especially with the development of China’s high-speed railway, locomotive manufacturing enterprises use strength aluminum alloy tube not only for car body covering parts, but more as structure body. The mechanical properties of aluminum alloy sheet ought to increase greatly, especially the fatigue properties. However when we use aluminum alloy, some plastic deformation may affect the fatigue life of aluminum alloy. Therefore plastic deformation on fatigue performance should no longer be ignored, so when we use these high-strength aluminum alloys,-the affect to fatigue properties must be considered.This paper firstly introduces the concept of S-N curve and P-s-n curve of fatigue test method and the data processing method. Analysising fatigue test and data of the experimental specimens in accordance with these methods. The author of this paper takes6061aluminum alloy as an example.Frist,giving some plastic deformation to a certain amount of6061aluminum alloy sheets, And then doing Fatigue test, in order to find out Fatigue limit. The P-s-n curve was got when confidence level is95%or90%and the survival is90%or99%. Finally, the fatigue life data were compared.In order to be more specific about the specimen fatigue life difference in three states, using t-test method to find out the different of this three states. Doing fatigue testing under the same stress level and then doing significant test to find out the different.Basing on fluctuation method fatigue test existing mean tensile stress and stress ratio r=0.3were taken on fatigue test-piece to investigate the influence, which the mean tensile stress acts on fatigue limit amplitude.After this, the results from the test and calculation results of several common stress translation methods were analyzed.