@article{ff5ed4b945b1488791b8a8bafd714593,
title = "Finite element analysis on initial crack site of porous structure fabricated by electron beam additive manufacturing",
abstract = "Ti6Al4V specimens with porous structures can be fabricated by additive manufacturing to obtain the desired Young{\textquoteright}s modulus. Their mechanical strength and deformation behavior can be evaluated using finite element analysis (FEA), with various models and simulation methodologies described in the existing literature. Most studies focused on the evaluation accuracy of the mechanical strength and deformation behavior using complex models. This study presents a simple elastic model for brittle specimens followed by an electron beam additive manufacturing (EBAM) process to predict the initial crack site and threshold of applied stress related to the failure of cubic unit lattice structures. Six cubic lattice specimens with different porosities were fabricated by EBAM, and compression tests were performed and compared to the FEA results. In this study, two different types of deformation behavior were observed in the specimens with low and high porosities. The adopted elastic model and the threshold of applied stress calculated via FEA showed good capabilities for predicting the initial crack sites of these specimens. The methodology presented in this study should provide a simple yet accurate method to predict the fracture initiation of porous structure parts.",
author = "Tsai, {Meng Hsiu} and Yang, {Chia Ming} and Hung, {Yu Xuan} and Jheng, {Chao Yong} and Chen, {Yen Ju} and Fu, {Ho Chung} and Chen, {In Gann}",
note = "Funding Information: Funding: This research was funded by Ministry of Science and Technology of Taiwan, grant number MOST 108-2218-E-992-320-MY2, 109-2622-E-992-013-CC3 and 106-2218-E-006-006. Funding Information: Acknowledgments: The authors gratefully acknowledge the sponsorship from the Ministry of Science and Technology of Taiwan, under project No. MOST 108-2218-E-992-320-MY2. The authors are thankful for the EBAM lab equipment and financial support from the Metal Industry Research and Development Centre (MIRDC). Funding Information: of the struts in the FEA results; the structure collapsed diagonally with the formation strain curve. With an increase in porosity, the deformation behavior shifted toward a of one shear band throughout the specimen. However, the high-porosity specimens layer-by-layer collapse and showed a uniform fluctuation in the plateau region. possessed maximum stresses at the center of the struts; the structures collapsed layer- 2. In terms of the elastic model (FEA), in the low-porosity specimens, where the stress by-layer. statics diagram showed a normal distribution, most of the stresses were smaller than the yield strengths. The maximum stress concentration was located at the edge of Author Contributions: Conceptualization, I.-G.C. and H.-C.F.; methodology, M.-H.T. and C.-M.Y.; the strut and the node. In contrast, in the high-porosity specimens, the stress statics shifted the low and high stresses into two peak distributions, and the maximum stress concentration was located at the center of the struts. 3. The applied threshold stresses were 100, 83, and 63 MPa for C4, C5, and C6, respec-Funding: This research was funded by Ministry of Science and Technology of Taiwan, grant number tively, which were close to the experimental results (110, 68, and 62 MPa). MOST 108-2218-E-992-320-MY2, 109-2622-E-992 -013 -CC3 and 106-2218-E-006-006. 4. By combining the compressive experimental results and FEA results, the initial failure sites of the low-porosity specimens were demonstrated to be located at the edge of Publisher Copyright: {\textcopyright} 2021 by the authors. Licensee MDPI, Basel, Switzerland.",
year = "2021",
month = dec,
day = "1",
doi = "10.3390/ma14237467",
language = "English",
volume = "14",
journal = "Materials",
issn = "1996-1944",
publisher = "MDPI AG",
number = "23",
}