Resonance Fatigue Failure Mechanism And Experimental Research

With the rapid development of modern industry,mechanical machines are in service under severe conditions.Vibration and fatigue damage are still the focus of attention in the engineering field.In particular,when the excitation frequency of the external load is close to the resonance frequency of the structure,there are many cases of fatigue failure caused by the structure resonance.Examples of accidents show that due to the rapid development of power machines in recent years,especially in the aviation field,some structures have to be serviced in a vibrating environment,so the vibration fatigue phenomenon has also increased.Therefore,it is more and more important to conduct vibration research on materials.The axial resonance fatigue test system is designed in this paper.The difference between axial resonance fatigue and conventional high cycle fatigue performance is mainly studied,and the failure mechanism of both is simply analyzed.The research content of this article can be divided into the following parts:1)An axial resonance fatigue test system is designed,and the test system is analyzed by finite element software to verify the feasibility of the test system.2)Some verification tests are conducted using this test system to verify the stability of the test system and the validity of the test data.Then the axial resonance fatigue test of 7050 aluminum alloy is completed based on this testing system.And the conventional high cycle fatigue test of 7050 aluminum alloy is carried out.3)By analyzing the experimental data,the axial resonance fatigue performance of 7050 aluminum alloy is measured,and an S-N curve of 7050 aluminum alloy under resonance conditions was fitted.The F-test and Student's test are used to check the compatibility of the two sets of test data.4)By studying the nature of fatigue failure,the factors affecting fatigue life are analyzed.The fatigue performance difference between resonance fatigue and conventional high cycle fatigue is analyzed.Macro and micro observations were performed on the fractures of the specimens,and the failure mechanisms of resonance fatigue and conventional fatigue were compared and analyzed.