Effective Design of the Graded Strut of BCC Lattice Structure for Improving Mechanical Properties

Abstract

In order improve the poor mechanical properties of the body-centred cubic (BCC) lattice structure, which suffers from the stress concentration effects at the nodes of the BCC unit cell, a graded-strut design method is proposed to increase the radii corner of the BCC nodes, which can obtain a new graded-strut body-centred cubic (GBCC) unit cell. After the relative density equation and the force model of the structure are obtained, the quasi-static uniaxial compression experiments and finite element analysis (FEA) of GBCC samples and BCC samples are performed. The experimental results show that for the fabricated samples with the same relative density, the GBCC can increase the initial stiffness by at least 38.20%, increase the plastic failure strength by at least 34.12%, compared with the BCC. Coupled experimental and numerical results not only suggest that the GBCC has better mechanical and impact resistance properties than the BCC, but also indicate that as the radii corner increases, the stress concentration effect at the node and the mechanical properties will be improved, which validates the proposed design method for graded-strut unit cells and can provide guidance for the design and future research on ultra-light lattice structures in related fields.

Compressive and Energy Absorption Properties of Pyramidal Lattice Structures by Various Preparation Methods

“…The mechanical properties of the lattice structure can be improved through nodeenhancement [21,22]. In this study, the effect of preparation method and strut materials are the focus of attention.…”

“…Another method to enhance the mechanical properties or energy absorption capacity is to modify the structure of node connecting the struts, where the stress concentration usually arises when subjected to compression or impact load. This method is relatively simple but very effective in increasing the energy absorption capacity of metallic lattice structures [21,22].…”

Experimental Research of Selected Lattice Structures Developed with 3D Printing Technology

“…Furthermore, their unit cell structures can be controlled and optimised to achieve the expected mechanical properties suitable for the given application. The use of gradient decomposition in spatial structures significantly modifies their mechanical properties and extends the range of potential applications [ 16 , 17 , 18 , 19 ].…”

Energy Absorption and Mechanical Performance of Functionally Graded Soft–Hard Lattice Structures

“…Moreover, many structures in the nature such as bone have distinctive properties. Therefore, lattice structures with graded changes in the size, properties and volume fraction, named functionally graded (FG) lattice structures, are exceptional alternatives [ 17 , 18 , 19 ]. Therefore, mechanical performance and energy absorption of two-dimensional (2D) and 3D lattice structures can be tuned by integrating graded size, multiple material (volume fraction of materials, soft-hard interactions and configurations) through rational design and triply periodic minimal surfaces (TPMS) or topology optimization [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ].…”