Abstract: The mechanics behaviour of the four aluminum alloys under cyclic strain control as well as the discrepancies of strain fatigue behaviour between transvers,longitudinal and high direction are analysed in the paper. The test results is shown that influence of different direction on strain fatigue life of alluminum alloys mainly depend on plastic of materials. Behaviour of cyclic stress strain on four aluminum alloys all exhibit cyclic strain hardning in longitudinal, transvers and high orientation. 7475T7351 alloys show the larger strain fatigue properties as compared with other three aluminum alloys.

Key words: aluminum alloys　tests, mechanical properties, stressst rain relationships, fa tigue (materials)