2021/03/11 by Tianchen Hu, Brandon Talamini, Hu, Tianchen +7
Engineering · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Metal Forming Simulation Techniques #Metallurgy and Material Forming #Numerical methods in engineering
paper · pdf · doi:10.48550/arxiv.2103.12524
openalex publication_date 2021/03/11 · openalex created_date 2021/03/29 · openalex updated_date 2026/07/28
A novel phase-field for ductile fracture model is presented. The model is developed within a consistent variational framework in the context of finite-deformation kinematics. A novel coalescence dissipation introduces a new coupling mechanism between plasticity and fracture by degrading the fracture toughness as the equivalent plastic strain increases. The proposed model is compared with a recent alternative where plasticity and fracture are strongly coupled. Several representative numerical examples motivate specific modeling choices. In particular, a linear crack geometric function provides an "unperturbed" ductile response prior to crack initiation, and Lorentz-type degradation functions ensure that the critical fracture strength remains independent of the phase-field regularization length. In addition, the response of the model is demonstrated to converge with a vanishing phase-field regularization length. The model is then applied to calibrate and simulate a three-point bending experiment of an aluminum specimen with a complex geometry. The effect of the proposed coalescence dissipation coupling on simulations of the experiment is first investigated in a two-dimensional plane strain setting. The calibrated model is then applied to a three-dimensional calculation, where the calculated load-deflection curves and the crack trajectory show excellent agreement with experimental observations. Finally, the model is applied to simulate crack nucleation and growth in a specimen from a recent Sandia Fracture Challenge.