Experimental and Computational Investigation of Lattice Sandwich Structures Constructed by Additive Manufacturing Technologies

Abstract

Additive Manufacturing (AM) technologies offer the ability to construct complex geometrical structures in short manufacturing lead time coupled with a relatively low production cost when compared to traditional manufacturing processes. The next trend in mechanical engineering design is the adaption of design strategies that build products with lightweight lattice geometries like sandwich structures. These structures possess low mass, large surface area to volume ratio, high porosity, and adequate mechanical behavior, which are properties of great importance in scientific fields such as bioengineering, automotive, and aerospace engineering. The present work is focused on producing sandwich structures with complex lattice patterns like the Triply Periodic Minimal Surface (TPMS) Schwarz diamond structure. The specimens were manufactured with two different Additive Manufacturing procedures employing various relative densities. More specifically, Material Jetting Printing (MJP) and Fused Filament Fabrication (FFF) processes were employed to investigate the performance of Acrylonitrile Butadiene Styrene (ABS) lightweight lattice structures. These structures were examined using digital microscopy in order to measure the dimensional accuracy and the surface characteristics of the utilized AM technologies. Furthermore, three-point bending tests and finite elements analyses have been applied to investigate the mechanical performance of the proposed technologies and designs as well as the influence of the relative density on the Schwarz diamond TPMS structure. The experimental results demonstrate that the investigated structure possesses a remarkable performance in respect to its weight due to the specific distribution of its material in space.

X-ray Tomography Investigation of the Quality of Architected Structures Obtained with Additive Manufacturing Processes

“…All these defects are attributed to the lack or partial fusion of the powder in the areas concerned, which generates surfaces with a significant roughness. These observations are consistent with the results of the literature on powder bed fusion ( [26] for the SLM (Selective Laser Melting) process, [27] for the EBM (Electron Beam Melting) process, [21,28] for the LPBF process) and material extrusion (FFF process [29]).…”

Architected Materials for Additive Manufacturing: A Comprehensive Review

“…The first implementation of architected materials and lattice structures was for parts with lightweight purposes in the automotive and aeronautics industries, due to their high porosity [ 3 , 4 , 5 , 6 ]. In detail, architected materials were used first as cores in sandwich-like structures, in order to reduce the mass and maintain strength and stiffness [ 72 , 73 ]. Currently, with the assistance of additive manufacturing technologies, the employment of architected materials is performed with the topology optimization of existing structural parts.…”

Design and Development of a Multi-Functional Bioinspired Soft Robotic Actuator via Additive Manufacturing

“…More specifically, the design of the dies was extracted from the 3D models of the pneumatic chambers and was amplified with air vents, for the extraction of the air during the molding process, and sealing parts to ensure that the molds were leakproof, as it is depicted in Figure 3 a,b. The material jetting AM technology was employed, namely the ProJet ® MJP 5600 (3D Systems, Rock Hill, SC, USA) 3D printer, for the production of the molds, due to its high dimensional accuracy up to 25 μm (16 μm layer height) [ 34 ]. In detail, for the external parts of the mold, a rigid polycarbonate-like transparent material, i.e., the VisiJet ® CR-CL 200 (3D Systems, Rock Hill, SC, USA), was utilized to monitor the flow of the silicone inside the mold.…”