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Modelling of localized ductile fracture with volumetric locking‐free tetrahedral elements
Author(s) -
Xu Yanjie,
Biswas Raja,
Poh Leong Hien
Publication year - 2020
Publication title -
international journal for numerical methods in engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.421
H-Index - 168
eISSN - 1097-0207
pISSN - 0029-5981
DOI - 10.1002/nme.6323
Subject(s) - materials science , finite element method , shearing (physics) , tapering , softening , fracture (geology) , structural engineering , spurious relationship , mechanics , composite material , mathematics , computer science , physics , engineering , statistics , computer graphics (images)
SUMMARY Finite element analysis of ductile fracture with tetrahedral elements faces two numerical issues: volumetric locking and mesh sensitivity. In this paper, two widely adopted remedies for volumetric locking (F‐bar and mixed field) are evaluated, and the superior performance of the mixed field method is demonstrated. Building on the mixed field formulation, a gradient enhancement is further incorporated to resolve the mesh sensitivity. It is shown that a localizing gradient enhancement can avoid a spurious spreading of damage induced by the conventional gradient approach. A locking‐free, regularized ductile fracture is first presented via a uniformly tapering plate example. Finally, a shear plate test on ferrite‐bainite steel is considered. Numerical results obtained with the proposed approach are shown to capture the rapid strain softening and localized shear fracture phenomenon observed experimentally.