Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
ON THE EVALUATION OF ELATOPLASTIC STRESSES DISTRIBUTION AROUND A CRACK TIP
Submission Author:
Mateus Bastos Neiva , RJ , Brazil
Co-Authors:
Mateus Bastos Neiva, Carlos Alberto de Almeida, Ivan Menezes
Presenter: Carlos Alberto de Almeida
doi://10.26678/ABCM.COBEM2023.COB2023-1520
Abstract
As has been shown by major recent publications, in the evaluation of stresses around a crack tip, throughout numerical simulations, three significant critical difficulties must be overcome: i) the steep high-stress variations in a region close to the tip, ii) the appropriate shape of the crack opening surface and iii) the correctness of the boundary conditions to be accounted for. Although currently available numerical tools can be used to surpass such difficulties as the Finite Element Method (FEM), the first mentioned difficulty may require robust and very refined models, a significant drawback in the convergence process to the numerical solution. In this work, a review of the numerical elastoplastic analysis of a classical problem in fracture mechanics is considered and evaluated and, based on the encountered difficulties, a semi-analytical procedure is then proposed to provide stress and strain distributions around a prescribed crack tip shape. A brief review of the recently published analytical results for solutions under elastic and elastoplastic material behaviors such the Williams and the HRR models, both possessing singular stress distribution fields, and the Creager-Paris modeling with a non-singular stress field, but having the material in the elastic range approach, are considered. Some numerical solutions with these modeling approaches are evaluated with the results obtained using 3D regular finite element discretization using the elastoplastic von Mises yielding criteria employed for the modeling of the crack tip blunt. Next, a semi-analytical model is proposed and discussed in the numerical solution considering the stress function definition as a state variable, with the material in the elastoplastic regime at the blunted crack, considering the crack face as with an elliptical shape. The major advantages of the proposed procedure are discussed in light of its accuracy and robustness.
Keywords
Finite Element Method, Fracture Mechanics, plasticity, Semi-analytical procedure, Elliptical shape crack face
