Effective Elastic Moduli of Metal Honeycombs Manufactured using Selective Laser Melting

Abstract

Purpose: Honeycomb cellular structures exhibit unique mechanical properties such as high specific strength, high specific stiffness, high energy absorption and good thermal and acoustic performance. This paper aims to use numerical modeling to investigate the effective elastic moduli, in-plane and out-of-plane, for thick-walled honeycombs manufactured using selective laser melting (SLM).

Design/methodology/approach: Theoretical predictions were performed using homogenization on a sample scale domain equivalent to the as-manufactured dimensions. A Renishaw AM 250 machine was used to manufacture hexagonal honeycomb samples with wall thicknesses of 0.2 to 0.5 mm and a cell size of 3.97 mm using 304 L steel powder. The SLM-manufactured honeycombs and cylindrical test coupons were tested using flatwise and edgewise compression. Three-dimensional finite element and strain energy homogenization were conducted to determine the effective elastic properties, which were validated by the current experimental outcomes and compared to analytical models from the literature.

Findings: Good agreement was found between the results of the effective Young's moduli ratios numerical modeling and experimental observations. In-plane effective elastic moduli were found to be more sensitive to geometrical irregularity compared to out-of-plane effective moduli, which was confirmed by the analytical models. Also, it was concluded that thick-walled SLM manufactured honeycombs have bending-dominated in-plane compressive behavior and a stretch-dominated out-of-plane compressive behavior, which matched well with the simulation and numerical models predictions.

Originality/value: This work uses three-dimensional finite element and strain energy homogenization to evaluate the effective moduli of SLM manufactured honeycombs.

Department(s)

Materials Science and Engineering

Second Department

Mechanical and Aerospace Engineering

Research Center/Lab(s)

Center for Research in Energy and Environment (CREE)

Second Research Center/Lab

Center for High Performance Computing Research

Third Research Center/Lab

Intelligent Systems Center

Comments

Published online: 11 Feb 2020

The authors would like to acknowledge the support from Center for Aerospace Manufacturing Technologies (CAMT).

Keywords and Phrases

Finite Element Analysis (FEA); Hexagonal Honeycombs; Homogenization; Selective Laser Melting (SLM)

International Standard Serial Number (ISSN)

1355-2546

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2020 Emerald Group Publishing Ltd., All rights reserved.

Publication Date

19 May 2020

Link to Full Text

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