Lattice materials composed by curved struts exhibit adjustable macroscopic stress-strain curves

Abstract

In this paper, a mechanism called buckling-dominated is proposed for the deformation of lattice materials. To investigate this mechanism and its utilization potentiality, sandwich panels with lattice cores composed by curved struts which follow a two-parameter trigonometric function were put forward. A two-step finite element method (FEM) were carried out to find the two parameters. Specimens with the two parameters were prepared and tested by quasi-static compression. The results indicate the macroscopic compressive stress-strain curves of them are adjustable by changing the struts curvatures. When this feature is utilized to design materials for energy-absorption, more favorable stress-strain curves can be obtained, i.e., the specific energy-absorbing of the designed materials are 39%–74% higher and energy-absorption efficiency are 32%–42% higher than common lattice materials with similar density, at 0.6 reference strain.