Eventos Anais de eventos
MECSOL 2022
8th International Symposium on Solid Mechanics
On the dependence of the initial yield stress on the stress triaxiality and the Lode parameter
Submission Author:
Raphael Mialhe , SP , Brazil
Co-Authors:
Raphael Mialhe, Larissa Driemeier
Presenter: Raphael Mialhe
doi://10.26678/ABCM.MECSOL2022.MSL22-0199
Abstract
For safety reasons, many structures are designed to work in elastic regime, making the material initial yield stress a critical value. Although there are many mathematical models available to describe the mechanical behavior of ductile materials, establishing mathematical relationships that weigh the influence of a complex stress state on the initial yield stress of the material is not a trivial task. In this context, the present work studies the influence of stress state on the onset of yield stress for different aluminum alloys through the numerical analyses of three different biaxial models. The experimental results for model training and validation were obtained from the literature. Firstly, the material parameters were determined by adjusting numerical and experimental force versus displacement curves. Then, finite element analyses were performed to extract stress invariants at the beginning of material yielding. Finally, a nonlinear regression was implemented to adjust the parameters of a polynomial to model the initial yield stress as a function of the stress triaxiality and Lode parameter. The results indicate that the yield stress behavior, for the tested range of triaxiality and Lode parameter values, can be robustly modelled by a fourth-order polynomial.
Keywords
biaxial experiments, yield criteria, stress state invariants, Lode angle, Triaxiality, Finite Element Analysis
