TY - JOUR
T1 - Deformation mechanisms and post-yielding behavior of additively manufactured lattice structures
AU - Bahrami Babamiri, Behzad
AU - Askari, Hesam
AU - Hazeli, Kavan
N1 - Funding Information:
This work was completed under the NASA , USA grant (contract number: 80MSFC18M0012 ). The authors would like to thank Dr. Omar Mireles and Dr. Omar Rodriguez at NASA Marshall Space Flight Center (MSFC) for assistance in manufacturing the lattice structure and their inputs during the project. The authors would also like to thank Dr. Jason Mayeur at the University of Alabama in Huntsville (UAH) for his valuable feedback and discussion. The authors would also like to thank Joseph Indeck at UAH for helping with experimental tasks and data analysis.
Funding Information:
This work was completed under the NASA, USA grant (contract number: 80MSFC18M0012). The authors would like to thank Dr. Omar Mireles and Dr. Omar Rodriguez at NASA Marshall Space Flight Center (MSFC) for assistance in manufacturing the lattice structure and their inputs during the project. The authors would also like to thank Dr. Jason Mayeur at the University of Alabama in Huntsville (UAH) for his valuable feedback and discussion. The authors would also like to thank Joseph Indeck at UAH for helping with experimental tasks and data analysis.
Publisher Copyright:
© 2019 The Authors.
PY - 2020/3
Y1 - 2020/3
N2 - This study develops an anisotropic generalization of the volumetric hardening model (VHM) to investigate the governing deformation mechanisms at the onset of yielding of additively manufactured lattice structure (AMLS) made of a nickel-based superalloy, Inconel 718 (IN718), under quasi-static loading. The discussion of deformation mechanisms relies on defining a new yield surface using a combination of experimental measurements and finite element simulations that enable the representation of three distinct behavioral features of IN718 lattice structures under mechanical loading including (1) tension-compression asymmetry of strut-level response; (2) tension-compression asymmetry of the aggregate response; and (3) hydrostatic pressure sensitivity of the strut-level response. Typically, the VHM is used to describe the aggregate response of lattice or foam materials to global loading. The VHM model could be directly applied at the strut-level; however, this would assume a one-to-one correspondence between the local and global response. Such an assumption is not justified a priori and could alter the evolution of the local deformation mechanisms and the resulting analysis of failure modes and structural degradation. Therefore, we introduce a modified VHM (or MVHM), which represents a more appropriate yield criterion. The Johnson-Cook damage criterion and damage evolution law, which is based on Hillerborg's fracture energy method, are coupled with the MVHM to investigate the damage initiation and evolution, and their influence on the global stress-strain response using finite element simulations.
AB - This study develops an anisotropic generalization of the volumetric hardening model (VHM) to investigate the governing deformation mechanisms at the onset of yielding of additively manufactured lattice structure (AMLS) made of a nickel-based superalloy, Inconel 718 (IN718), under quasi-static loading. The discussion of deformation mechanisms relies on defining a new yield surface using a combination of experimental measurements and finite element simulations that enable the representation of three distinct behavioral features of IN718 lattice structures under mechanical loading including (1) tension-compression asymmetry of strut-level response; (2) tension-compression asymmetry of the aggregate response; and (3) hydrostatic pressure sensitivity of the strut-level response. Typically, the VHM is used to describe the aggregate response of lattice or foam materials to global loading. The VHM model could be directly applied at the strut-level; however, this would assume a one-to-one correspondence between the local and global response. Such an assumption is not justified a priori and could alter the evolution of the local deformation mechanisms and the resulting analysis of failure modes and structural degradation. Therefore, we introduce a modified VHM (or MVHM), which represents a more appropriate yield criterion. The Johnson-Cook damage criterion and damage evolution law, which is based on Hillerborg's fracture energy method, are coupled with the MVHM to investigate the damage initiation and evolution, and their influence on the global stress-strain response using finite element simulations.
KW - Additive manufacturing
KW - Anisotropic behavior
KW - Damage
KW - Lattice structure
KW - Volumetric hardening model
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U2 - 10.1016/j.matdes.2019.108443
DO - 10.1016/j.matdes.2019.108443
M3 - Article
AN - SCOPUS:85078097677
SN - 0264-1275
VL - 188
JO - Materials and Design
JF - Materials and Design
M1 - 108443
ER -