Validation of material removal simulation based on experimental investigation of additively manufactured AISI SS 316L

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master_Asghar_Adnan_2025.pdf (2.91 MB)

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School of Engineering | Master's thesis
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Date

2025-05-26

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Production Engineering

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Degree programme

Master's programme in Mechanical Engineering

Language

en

Pages

90

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Abstract

This thesis investigates and validates a finite element analysis (FEA) simulation framework for the additive manufacturing (AM) of an AISI 316L stainless steel component produced via laser powder bed fusion (LPBF). The central focus of this study is on simulating and experimentally validating the evolution of geometric distortions because of residual stress formation and redistribution during AM and post-processing stages, respectively. A sequentially coupled thermo-mechanical simulation approach was implemented in Abaqus. The thermal history during the LPBF process was first modelled, followed by structural analyses to capture residual stress development. Subsequent simulation stages included virtual substrate detachment and material removal mimicking electrical discharge machining (EDM), aiming to replicate real-world stress relaxation and deformation behaviours. To validate the simulation results, the part was fabricated using LPBF under controlled parameters. Substrate and the material removal processes were executed using EDM. After each stage – LPBF printing, substrate removal, and material removal – dimensional deviations in the part were quantified using a high-precision coordinate measuring machine (CMM). These measurements enabled direct comparison between simulated predictions and experimental outcomes. The results reveal a strong correlation between simulated and measured geometric deflections, particularly in regions sensitive to residual stress relief. The simulation effectively predicted both the magnitude and spatial distribution of distortions introduced during and after AM stages. This validated framework demonstrates the reliability of thermo-mechanical modelling for LPBF parts and confirms its potential for predicting post-build distortions with high fidelity.

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Supervisor

Niemi, Esko

Thesis advisor

Ullah, Rizwan

Keywords

additive manufcturing, laser powder bed fusion, finite element simulations, simulation-experiment correlation, residual stress, geometric deviations

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https://urn.fi/URN:NBN:fi:aalto-202506094330

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