Theses and Dissertations
ORCID
https://orcid.org/0000-0001-7665-4025
Advisor
Priddy, Matthew W.
Committee Member
Linkan, Bian
Committee Member
McClelland, Zackery B.
Committee Member
Doyl, Dickel E.
Date of Degree
12-12-2025
Original embargo terms
Embargo 2 years
Document Type
Dissertation - Open Access
Major
Engineering (Mechanical Engineering)
Degree Name
Doctor of Philosophy (Ph.D.)
College
James Worth Bagley College of Engineering
Department
Michael W. Hall School of Mechanical Engineering
Abstract
The leveraging of part scale thermal effects models to predict the impact of residual stresses and part distortion induced in laser-powder bed fusion (L-PBF) additively manufactured (AM) components can be an effective means for determining how an AM component will behave in an application with harsh loading conditions such as high strain-rates. Therefore, this work develops a sequentially-coupled thermomechanical finite element (FE) workflow for predicting the impact of thermal effects on the dynamic loading response of L-PBF 316L stainless steel components. The initial task was to develop the additive manufacturing process event series generations code, AMPES, to create raster scanning paths for the heat source that mimic the laser during the L-PBF process. To demonstrate the utility of AMPES and the part scale thermomechanical FE workflow’s viability, pilot work modeling the thermal history of a bridge specimen printed out of 316L and the residual stress state of an L-shape part printed out of Inconel 718 with previously published neutron diffraction data was conducted. The pilot work showed that AMPES could reliably mimic the raster scanning strategy of the laser in L-PBF, determined that an isotropic temperature dependent linear elastic-perfectly plastic (EPP) material model had sufficient fidelity for capturing the thermal effects in a part scale model, and that a sparse thermal history method is needed for modeling full AM components in a reasonable amount of time. Furthermore, though it was determined that EPP is sufficient for capturing the thermal effects of L-PBF, EPP is not suited for predicting dynamic loading with its inability to capture plastic hardening. Therefore, a series of experiments were conducted to calibrate a Johnson-Cook (JC) strengthening model to L-PBF 316L that was then validated by Taylor anvil experiments. Finally, the part scale thermal effects FE workflow was used to model the residual stresses induced on a L-PBF 316L plate used in a ballistic test. A key takeaway was that imposing residual stresses only slightly reduced the energy absorption capacity of the ballistic impact predictions using the L-PBF 316L JC model as opposed to neglecting the residual stresses. Both predictions were validated by experiments.
Recommended Citation
Failla Jr., David Pervis, "Modeling the ballistic performance of laser-powder bed fusion additively manufactured 316L stainless steel targets with as-built residual stresses" (2025). Theses and Dissertations. 6765.
https://scholarsjunction.msstate.edu/td/6765
