Efficient virtual element modeling of the bending failure in BCC lattice sandwich panels manufactured by L-PBF

Abstract

Lattice structures are gaining increasing interest in the aerospace field thanks to their promising applications. They can be used in metal sandwich panels as a core to reduce weight and provide additional functions to the structure. Laser Powder Bed Fusion (L-PBF) represents one of the best solutions to manufacture metal structures when high resolution is required. Finite element-based simulations of lattice structures’ complex geometry require an extremely fine mesh, leading to prohibitively high computational costs and making the finite element model impractical for analysis. The Virtual Element Method (VEM) is a recently developed numerical technique that provides several advantages over the traditional finite element method. These advantages include the capability to manage complex geometries accurately, enhanced performance with distorted meshes, and increased flexibility in mesh generation. This paper introduces a novel and computationally efficient numerical approach that combines a non-linear Virtual Element Method formulation and equivalent two-dimensional modeling to predict the bending failure of Body-Centered Cubic (BCC) lattice sandwich panels fabricated via L-PBF. To validate and illustrate the effectiveness and potential of the proposed approach, numerical results are compared with experimental observations. For this purpose, a range of specimen configurations featuring different unit cell sizes and beam radius values were produced and tested. The findings reveal a strong alignment between the numerical predictions and experimental data and provide valuable insights into the failure mechanisms involved.