Finite Element Analysis On The Fatigue Crack Growth Parameter Of High Strength Aluminum Alloy Under The Tension-Compression Loading

The classical theory thought presses the load not to contribute to the crack expansion, Topper et al. through the experiment proved presses the load the existence regarding the excel in aluminum alloy rate of expansion is influential, but is unable to explain this kind of phenomenon existence reason.This article to pulls through the electron microscope presses under the load the fracture growth phenomenon to carry on the observation, obtains one in the observation foundation through the theory inferential reasoning to pull presses under the load the fracture growth speed formula, through the computation comparison, the crack which the formula reflected in pulls presses the experimental result which under load rate of expansion and Topper et al. do to tally extremely.This article simultaneously the application elastoplasticity finite element method established has pulled presses the load fatigue cracking expansion model, in the experiment altogether establishes five to have the different length center to penetrate the crack excel in aluminum alloy board the finite element model, carried on separately pulls presses the load simulation analysis.Finite element in experiment condition and Topper et al. test the condition to be completely same, through this experiment, experimented under the pressure load which inferred for front the fatigue cracking state-of-art parameter influence for the theory and the experiment has provided the powerful finite element proof.The result indicated that, presses the load to have the remarkable influence to the fatigue of metal crack state-of-art parameter, as soon as under the same stress intensity factor condition, in pulls - presses the load cycle, the crack acme reverse plastic area along with presses the load the increase to increase, the crack acme opens the displacement along with to press the load to increase reduces, occurs in the cyclic loading pressure load is influential to the crack state-of-art plastic deformation, the massive plastic deformation occurs is pressing the load load process, presses the load the size is the decision fatigue cracking state-of-art parameter major effect factor.The theory and the finite element experiment explained together why in pulls presses under the load the crack expansion is receives the ultimate working capacity factor and the biggest pressure load influence, presses under the load the crack acme reverse plastic area fill-out, in presses under the load the crack rate of expansion to increase these phenomena.