Study of the slant fracture in solid and hollow cylinders: Experimental analysis and numerical prediction

Abstract

This paper is devoted to the numerical and experimental study of ductile fracture in bulk metal forming of the 2017A-T4 aluminum alloy. From an experimental standpoint, the ductile fracture of the 2017A-T4 aluminum alloy is investigated under compressive load. Two cross-sections of solid and hollow specimens are considered. The mechanical behavior and the microstructure of the 2017A-T4 aluminum alloy were characterized. It is found that the well-known barrel shape is obtained when a compressive load is applied. Analyses of fracture topographies show a ductile fracture with dimples under tension and coexistence of ductile fracture with dimples and slant under compression. The classical physically-based Gurson-Tvergaard-Needleman (GTN) model and its extension to incorporate shear mechanisms to predict failure at low-stress triaxiality are considered. These two models have been extended to take into account the thermal heating effect induced by the mechanical dissipation within the material during the metal forming process. The two models have been implemented into the finite element code Abaqus/Explicit using a Vectorized User MATerial (VUMAT) subroutine. Numerical simulations of the forging process made for hollow and solid cylindrical specimens show good agreement with experimental results. In contrast with the GTN model, the modified GTN model incorporating shear mechanisms can capture the final material failure.

Sensitivity of Stainless Steel Fracture to Triaxiality Factor and Lode Parameter Using Dislocation Density Approach

“…The model has been implemented in Abaqus/explicit using the VUMAT user subroutine, including the radial return algorithm to solve the material non-linearity problem [8][9][10]. The numerical integration of the dislocation densities is carried out using the backward/implicit Euler method:…”

A numerical-experimental coupled method for the identification of model parameters from µ-SPIF test using a finite element updating method

“…The corresponding implementation method of the modified Gurson model in shear loading is developed in the ABAQUS/Explicit finite element code, using a user material constitutive subroutine (VUMAT). The implementation of the constitutive law is carried out using the algorithm proposed by Aravas for pressure-dependent plasticity models, which is also based on elastic prediction and plastic correction [39][40][41][42].…”

Cyclic behavior of AA2024 aluminum alloy under different loading paths and heat treatments

“…The fatigue life of aluminum alloys is sensitive to the loading path, and the load path sensitivity is influenced by a number of factors, such as the material properties, loading conditions, and microstructure. [12][13][14][15] Already in 1970, Miller et al 16 called attention to the effect of strain rate on the cyclic behavior of materials, emphasizing the need for further research on the cyclic stress-strain curve. Woodthorpe et al 17 Many authors have studied the cyclic behavior of aluminum alloys under various conditions such as heat treatments, anisotropy, strain rate, mean strain, and squeeze casting in stress control tests.…”

“…Recently, some research confirmed that the loading path and heat treatment can have a significant effect on the fatigue life and fracture mode of aluminum alloys. The fatigue life of aluminum alloys is sensitive to the loading path, and the load path sensitivity is influenced by a number of factors, such as the material properties, loading conditions, and microstructure 12–15 …”