Eventos Anais de eventos
MECSOL 2019
7th International Symposium on Solid Mechanics
Evaluation of the Fatigue Limits of Aluminum Alloys by Thermographic and eN techniques
Submission Author:
Gabriela Cristina Paiva Martins , RJ
Co-Authors:
Gabriela Cristina Paiva Martins, Carlos Filipe Cardoso Bandeira, Gabriela Wegmann Lima, Jaime T P Castro
Presenter: Gabriela Cristina Paiva Martins
doi://10.26678/ABCM.MECSOL2019.MSL19-0147
Abstract
It is well-known that when a material is subjected to cyclic loading, its temperature increases. Since fatigue damage is caused by cyclic plasticity, a dissipative process, such temperature increments are much more pronounced under loadings above the fatigue limit of the material. Based on this evidence, an efficient thermographic method was proposed as an alternative way to measure fatigue limits of steels. This work addresses the experimental problems associated with the evaluation of fatigue limits of aluminum alloys using a variation of the thermal approach proposed by La Rosa and Risitano, which correlates temperature increments with several loading amplitudes and defines the fatigue limit as the stress below which no significant heat generation is measured. However, unlike in steels, in aluminum alloys the number of cycles needed to achieve temperature stabilization is highly dependent on the stress amplitudes, an issue that must be properly addressed in the measurement procedures. To verify the results obtained by thermography, the fatigue limit of the tested Al alloy (assumed to be associated, as usual to a life of 5.10^8 cycles) is estimated by extrapolating its eN curve measured by standard procedures to such very long life.
Keywords
fatigue, Fatigue Limit, thermographic method, eN extrapolation
