Fracture mechanics of laser sintered cracked polyamide for a new method to induce cracks by additive manufacturing
Fracture mechanics of laser sintered cracked polyamide for a new method to induce cracks by additive manufacturing
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DOI：
10.1016/j.polymertesting.2016.01.024
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发表时间：
2016-04-01
期刊：
影响因子：
5.1
通讯作者：
Zucchelli, A.
中科院分区：
文献类型：
--
作者：
Brugo, T.;Palazzetti, R.;Zucchelli, A.
本文对选择性激光烧结(SLS)制备的试件进行了实验研究，旨在为设计3D打印件时提供指导，并为3D复杂零件断裂力学领域的进一步发展奠定基础。目的是研究聚酰胺(PA)3D打印试件中构筑方向的影响，并评估用于断裂力学研究的烧结过程是否能直接引发裂纹。用数字图像相关法(DIC)对试验进行了监测，并用显微镜对断口进行了分析。结果表明，力学性能较好的试件是所有层中都含有部分裂纹的试件。另一方面，与裂纹平面平行的层为裂纹的扩展提供了有利的路径。DIC和断口研究表明，在某些条件下，小半径的几何图形或太接近的表面可能会粘合在一起，这取决于打印机的分辨率。实验还表明，SLS能够打印内部裂纹的试件，可用于研究复杂零件或内部裂纹零件的断裂力学。(C)2016爱思唯尔有限公司。保留所有权利。
This paper presents an experimental investigation on specimens manufactured by Selective Laser Sintering (SLS), with the purposes of giving designers advice when designing 3D printed parts, and laying the basis for a step forward in the field of fracture mechanics of 3D complex parts.The aim is to investigate the effect of building direction in Polyamide (PA) 3D printed samples and to assess whether a crack can be initiated directly from the sintering process for fracture mechanics study purposes.Six different configurations of Mode I Compact Tension (CT) specimens were manufactured and tested; the experiments were monitored by Digital Image Correlation (DIC) and fractured surfaces were analyzed using microscopy.Results showed that samples with better mechanical performance are those in which all the layers contain a portion of the crack. On the other hand, those with layers parallel to the crack plan offer a preferential pathway for the crack to propagate. DIC and fractography investigations showed that, under certain conditions, small-radius geometries, or too-close surfaces may bond together depending on printer resolution. Experiments also showed that SLS is capable of printing specimens with internal cracks that can be used to study fracture mechanics of complex parts or parts with internal cracks. (C) 2016 Elsevier Ltd. All rights reserved.