Abstract

Sandwich structures are widely used due to their light weight, high specific strength, and high specific energy absorption. Three-dimensional (3D) printing has recently been explored for creating the lattice cores of these sandwich structures. Experimental evaluation of the mechanical response of lattice cell structures (LCSs) is expensive in time and materials. As such, the finite element analysis (FEA) can be used to predict the mechanical behavior of LCSs with many different design variations more economically. Though there have been several reports on the use of FEA to develop models for predicting the post-yielding stages of 3D-printed LCSs, they are still insufficient to be a more general purpose due to the limitations associated with the lattice prediction behavior of specific features, certain geometries, and common materials along with showing sometimes poor prediction due to the computationally cheap elements out of which these models have been composed in most cases. This study focuses on the response of different LCSs at post-yielding stages based on the hexahedral elements to capture accurately the behaviors of 3D-printed polymeric lattices made of the Acrylonitrile Butadiene Styrene material. For this reason, three types of lattices such as body centered cubic, tetrahedron with horizontal struts, and pyramidal are considered. The FEA models are developed to capture the post-yielding compressive behavior of these different LCSs. These models are used to understand and provide detailed information of the failure mechanisms and relation between post-yielding deformations and the topologies of the lattice. All of these configurations were tested before experimentally during compression in the z-direction under quasi-static conditions and are compared here with the FEA results. The post-yielding behavior obtained from FEA matches reasonably well with the experimental observations, providing the validity of the FEA models.

中文翻译：

---

3D打印聚合物晶格结构屈服后行为的计算研究

摘要

三明治结构因其重量轻、比强度高、比能量吸收高而被广泛使用。最近已经探索了三维 (3D) 打印来创建这些夹层结构的晶格核心。晶格单元结构 (LCS) 的机械响应的实验评估在时间和材料上都是昂贵的。因此，有限元分析 (FEA) 可用于更经济地预测具有许多不同设计变化的 LCS 的机械行为。尽管已经有几篇关于使用 FEA 开发模型来预测 3D 打印 LCS 的屈服后阶段的报告，但由于与特定特征的晶格预测行为相关的限制，它们仍然不足以成为更通用的用途, 某些几何形状, 和常见的材料，以及由于在大多数情况下构成这些模型的计算成本低的元素，有时显示出较差的预测。本研究侧重于基于六面体元素的不同 LCS 在屈服后阶段的响应，以准确捕捉由丙烯腈丁二烯苯乙烯材料制成的 3D 打印聚合物晶格的行为。出于这个原因，考虑了三种类型的晶格，例如体心立方、具有水平支柱的四面体和金字塔形。开发 FEA 模型是为了捕捉这些不同 LCS 的屈服后压缩行为。这些模型用于了解和提供有关失效机制以及屈服后变形与晶格拓扑之间关系的详细信息。准静态条件下的z方向，并在此与 FEA 结果进行比较。从 FEA 获得的屈服后行为与实验观察结果相当吻合，从而提供了 FEA 模型的有效性。