Additive Manufacturing and Experimental Analysis of a Beam with a 2D Triangular Substructure

The additive manufacturing and experimental analysis of a beam with a 2D triangular substructure continues a study based on prior investigations into higher-order elasticity models for Bernoulli-Euler and Timoshenko beams with periodic triangular substructures (Khakalo et al. in Int J Eng Sci 127:33–52 (2018), [1]). The primary objective of this work is to validate a higher-order elasticity model. To pursue these objectives, beams with 2D triangular substructures were manufactured using both fused filament fabrication and stereolithography techniques and subjected to comprehensive experimental analyses in the form of tensile tests. Three distinct types of beams were created, differing in the number of layers of triangular substructures-namely, one layer, two layers, and four layers. Additionally, two different materials, PolyLActide (PLA) and epoxy, were used. An additional investigation using a laser extensometer was conducted to determine material properties for epoxy experimentally. Based on the outcome of this investigation, further bending tests will be performed in a future paper. The higher material parameter denoted by g was quantitatively determined based on the results of the experimental investigations using an inverse analysis. These results are specifically applicable to the described substructure variations and effectively capture the elastic size effects. In a comprehensive experimental study, in addition to general analyses of the beam with a 2D triangular substructure, the influence of printing parameters is determined and discussed.