Banca de DEFESA: Simelia dos Santos

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : Simelia dos Santos
DATE: 15/03/2024
TIME: 09:00
LOCAL: Videoconferência Plataforma Teams
TITLE:

Assessment of Multiaxial and Classical Methods in Fatigue Life Prediction: Studies on SAE 4130 and AL 2024-T3 Alloys

KEY WORDS:

Critical planes, experimental life, multiaxial fatigue, shear stress, mean stress.

PAGES: 72
BIG AREA: Engenharias
AREA: Engenharia Mecânica
SUMMARY:

The present work aims to compare fatigue life prediction under the influence of mean stress for SAE 4130 steel and Al 2024-T3 aluminum alloys, using both multiaxial and classical models, including critical plane models. For this purpose, the routines of the method were implemented using MATLAB software directly, for determining the critical plane, including in-phase and outof-phase loading, scanning how normal and shear stresses vary on the plane, defining and storing the maximum stress evolution on each cutting plane, and calculating life predictions. The method consists of predicting fatigue life and failure plane orientations through maximum normal and shear stress amplitudes. To evaluate the method, critical planes of multiaxial models were estimated, followed by the calibration of Modified Wöhler Curve constants, and calibrations of traditional Walker and Kwofie models. Life predictions were made for SAE 4130 steel and Al 2024-T3 alloy considering experimental tests available in the literature for different loading ratios under tensile stress with different stress ratios. The validation of life prediction models, considering both multiaxial and uniaxial models, was carried out through analytical comparison between estimated and experimental lives. The results were evaluated through the performance of the error index and a confidence band of  3 lives, allowing an analysis of the proximity between predicted and experimental lives. Analyzing the results obtained from life predictions based on the presented results, there does not seem to be a single fatigue life prediction model that is superior for both SAE 4130 steel and Al 2024-T3 aluminum alloy. However, it is observed that the Walker and Kwofie models stand out as good options, offering reasonably satisfactory predictions for both materials

COMMITTEE MEMBERS:
Interno - 1668114 - DANIEL MONTEIRO ROSA
Interno - 1722212 - EDER LIMA DE ALBUQUERQUE
Presidente - 1249764 - JORGE LUIZ DE ALMEIDA FERREIRA
Externo à Instituição - MARCUS VINICIUS COSTA SA - IFB