Evaluation of the Equivalent Mechanical Properties of Lattice Structures Based on the Finite Element Method

Abstract

Lattice structures have excellent mechanical properties and can be designed by changing the cellular structure. However, the computing scale is extremely large to directly analyze a large-size structure containing a huge number of lattice cells. Evaluating the equivalent mechanical properties instead of the complex geometry of such lattice cells is a feasible way to deal with this problem. This paper aims to propose a series of formulas, including critical structural and material parameters, to fast evaluate the equivalent mechanical properties of lattice structures. A reduced-order model based on the finite element method and beam theory was developed and verified by comparing it with the corresponding full model. This model was then applied to evaluate the equivalent mechanical properties of 25 types of lattice cells. The effects of the material Young’s modulus and Poisson’s ratio, strut diameter, cell size, and cell number on those equivalent mechanical properties were investigated and discussed, and the linear relationship with the material parameters and the non-linear relationship with the structural parameters were found. Finally, a series of analytical-fitting formulas involving the structural and material parameters were obtained, which allows us to fast predict the equivalent mechanical properties of the lattice cells.

A Data-Driven Constitutive Model for 3D Lattice-Structured Material Utilising an Artificial Neural Network

“…Figure 1 depicts the combination of two unit cells to create a new structure unit cell for the purpose of our research. The unit cell depicted in Figure 1a, referred to as a grid [25], tri-axis cubic (TAC) [26], or centred-cubic (CC) unit cell [27,28], is merged with the body centred-cubic (BCC) unit cell, which is illustrated in Figure 1b, resulting in the formation of a new unit cell, shown in Figure 1c.…”

“…Figure 1 depicts the combination of two unit cells to create a new structure unit cell for the purpose of our research. The unit cell depicted in Figure 1a, referred to as a grid [25], tri-axis cubic (TAC) [26], or centredcubic (CC) unit cell [27,28], is merged with the body centred-cubic (BCC) unit cell, which is illustrated in Figure 1b, resulting in the formation of a new unit cell, shown in Figure 1c. The motivation behind the concept of integrating two unit-cells into a single structure was the intent to combine the distinct mechanical benefits and behaviour of each unit cell into a novel unit cell.…”

Mechanical Behavior and Material Modeling of Fused Filament Fabricated PEEK based on TPMS Lattices: A Comparative Study

“…The effective modulus was computed using Eq. ( 6) involving total compressive force (F), lattice structure dimensions (Lx, Ly, and Lz), and average displacement in the z direction (w) [59]. The yield strength was calculated using 0.2% offset criteria, and the modulus of resilience was measured through the area of the curve in the elastic region.…”

Towards Realistic Numerical Modelling of Thin Strut-Based 3d-Printed Structures

“…The number of numerical and experimental studies investigating the mechanical properties of strutbased lattice structures has significantly increased over the last few years (Karamooz Ravari and Kadkhodaei, 2014;Xiao et al, 2015;Tancogne-Dejean et al, 2016;Gautam et al, 2018;Kummert et al, 2021). Several studies have been involved in predicting the mechanical properties without calibrating the numerical models from the experimental analysis of printed structures (Park et al, 2014;Al-Saedi et al, 2018;Xia et al, 2022). However, given the significance of a realistic numerical model, the focus has been recently shifting towards incorporating experimental data from the printed structures, for example, geometrical deviations and material properties into the numerical models (Gorguluarslan et al, 2015;Tkac et al, 2020).…”