Mechanical performances of metal-polymer sandwich structures with 3D-printed lattice cores subjected to bending load

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(2020) 20:89

ORIGINAL ARTICLE

Mechanical performances of metal‑polymer sandwich structures with 3D‑printed lattice cores subjected to bending load Zhaobing Liu1,2,3   · Hantang Chen1 · Shuaiqi Xing1 Received: 25 March 2020 / Revised: 6 July 2020 / Accepted: 13 July 2020 © Wroclaw University of Science and Technology 2020

Abstract In this article, we propose a new class of metal-polymer architected sandwich structures that exhibit different mechanical behaviors. These lightweight sandwich structures have been made of aluminum face sheets and 3D-printed lattice cores with 2D (Bi-grid, Tri-grid, Quadri-grid and Kagome-grid) and 3D (face-centered cubic-like and body-centered cubic-like) topologies. Finite element simulation and experimental tests were carried out to evaluate mechanical performances of the proposed sandwich structures under quasi-static three-point bending load. Specifically, the damage-tolerant capability, energy absorption and failure mechanisms of these sandwich structures were investigated and evaluated through a combination of analytical, numerical and experimental methods. It is found that sandwich structures with 3D face and body-centered cubic-like cores can provide more excellent flexural stiffness, strength and energy absorption performance. These enhanced mechanical features could be further explained by a so-called ‘Stress Propagation’ mechanism through finite element analysis (FEA) that can facilitate sandwich structures with 3D cores, especially body-centered cubic-like one, to transfer bending loads from central lattice units across neighboring ones more efficiently than 2D cores. Furthermore, core cracking is the main failure mode for the proposed sandwich structures, which is primarily caused and dominated by bending-induced tensile stress followed by shear stress. It is worth mentioning that our findings provide new insights into the design of novel lightweight sandwich composites with tailored mechanical properties, which can benefit a wide variety of high-performance applications. Keywords  Sandwich structures · 3D printing · Lattice cores · Failure mechanism · Energy absorption

1 Introduction Lightweight sandwich structures assembled by face sheets and various cores are extensively used in aerospace, transport, civil and military sectors as they can offer excellent multifunctional properties such as high stiffness/strengthto-weight ratio, good thermal insulation and high energyabsorption capabilities [1, 2]. The mechanical performances of lightweight sandwich structures can be enhanced and optimized with well-designed cores that can carry flexural, * Zhaobing Liu [email protected]; [email protected] 1



School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430070, China

2



Hubei Digital Manufacturing Key Laboratory, Wuhan University of Technology, Wuhan 430070, China

3

Institute of Advanced Materials and Manufacturing Technology, Wuhan University of Technology, Wuhan 430070, China



compression and shear loads, and with soli