Effects of infill patterns on the strength and stiffness of 3D printed topologically optimized geometries
Effects of infill patterns on the strength and stiffness of 3D printed topologically optimized geometries
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DOI：
10.1108/rpj-11-2019-0290
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发表时间：
2021-08
影响因子：
3.9
通讯作者：
Nadim S Hmeidat;Bailey Brown;Xiu Jia;N. Vermaak;B. Compton
中科院分区：
文献类型：
--
作者：
Nadim S Hmeidat;Bailey Brown;Xiu Jia;N. Vermaak;B. Compton
目的与材料挤压添加剂制造(AM)相关的机械各向异性使复杂结构的设计复杂化。本研究旨在研究材料挤压AM提供的设计选择--即填充模式的选择--对给定优化拓扑的结构性能和最佳性的影响。对这些影响的解释提供了证据，证明使用结合各向异性行为的设计工具对于设计通过AM制造的真正最优结构是必要的设计/方法/方法解决了厚梁在三点弯曲中柔度最小化的基准拓扑优化(TO)问题，并使用熔丝制造打印了所得到的几何图形。使用多种填充图案打印优化后的几何形状，并对其强度、刚度和破坏行为进行了分析和比较。在弯曲试验的同时，用ABAQUS进行了相应的弹性有限元分析。有限元分析使用在拉伸和剪切测试中获得的材料特性来定义正交各向异性复合材料层，并在物理试件中模拟单独的打印层。发现试验表明，不同填充图案的结构之间的刚度差异高达22%，破坏荷载差异高达426%。观察到的失效模式也高度依赖于填充图案，对于层之间一致的所有填充图案，故障沿着打印界面传播。使用正交异性复合材料层板的弹性有限元分析可以准确地预测印刷结构的刚度，但简单的最大应力破坏准则不足以预测强度。尽管如此，有限元应力等值线被证明在识别印刷结构中的故障位置方面是有益的。原创性/价值这项研究使用经典的几何方法来量化印刷结构中填充图案的影响。提出的结果建立了一个基准，可用于指导面向新兴制造业的发展，以纳入与方向相关的、特定于工艺的材料特性的协议。
Purpose Mechanical anisotropy associated with material extrusion additive manufacturing (AM) complicates the design of complex structures. This study aims to focus on investigating the effects of design choices offered by material extrusion AM – namely, the choice of infill pattern – on the structural performance and optimality of a given optimized topology. Elucidation of these effects provides evidence that using design tools that incorporate anisotropic behavior is necessary for designing truly optimal structures for manufacturing via AM. Design/methodology/approach A benchmark topology optimization (TO) problem was solved for compliance minimization of a thick beam in three-point bending and the resulting geometry was printed using fused filament fabrication. The optimized geometry was printed using a variety of infill patterns and the strength, stiffness and failure behavior were analyzed and compared. The bending tests were accompanied by corresponding elastic finite element analyzes (FEA) in ABAQUS. The FEA used the material properties obtained during tensile and shear testing to define orthotropic composite plies and simulate individual printed layers in the physical specimens. Findings Experiments showed that stiffness varied by as much as 22% and failure load varied by as much as 426% between structures printed with different infill patterns. The observed failure modes were also highly dependent on infill patterns with failure propagating along with printed interfaces for all infill patterns that were consistent between layers. Elastic FEA using orthotropic composite plies was found to accurately predict the stiffness of printed structures, but a simple maximum stress failure criterion was not sufficient to predict strength. Despite this, FE stress contours proved beneficial in identifying the locations of failure in printed structures. Originality/value This study quantifies the effects of infill patterns in printed structures using a classic TO geometry. The results presented to establish a benchmark that can be used to guide the development of emerging manufacturing-oriented TO protocols that incorporate directionally-dependent, process-specific material properties.