Auxetic materials have a negative Poisson's ratio, therefore they expand in all directions when stretched. High-resolution 3D scan data of auxetic foam was obtained from the synchrotron facilities at the University of Washington. The data was automatically segmented and meshed using ScanIP and the +FE module. The simulations were performed using Abaqus®, Fluent and LS-Dyna.
G. Limbert, First Numerics • G. Tabor, University of Exeter • B. Walker (ARUP)
A high resolution MicroCT scan (3µm) of the auxetic foam was imported into ScanIP. Noise reduction on the background image was applied and main regions were segmented using the automated threshold tool. Two masks representing the foam and surrounding air were extracted.
The +FE module was used to generate a multipart mesh for finite element analysis within minutes. The software guaranties matching nodes and elements at the contact surface. Also node sets were created at the boundaries of the material. Several meshes were exported to Abaqus®, Fluent and LS-DYNA.
Finite Element and Fluid Flow simulations were run. Abaqus® was used to perform a structural analysis showing elastoes within the materials. In Fluent a fluid flow simulation was run, showing the flow velocity through the air domain and fluid-solid interaction. Finally an impact simulation was performed using LS-DYNA to show the deformation of the foam under a dynamic load. ►Videos
This animation shows the result of the compression from LS-Dyna simulation in Oasys D3Plot. The analysis did not require any remeshing during the analysis which demonstrates the high quality mesh achieved from +FE.
The auxetic foam mesh was also subjected to a shear load in LS-DYNA. This Oasys D3Plot animation shows the response of the foam as the top and bottom surface nodes are translated in opposing directions.
The auxetic foam mesh was also subjected to a tension test in LS-DYNA. This Oasys D3Plot animation shows the response of the foam as the top nodes are translated vertically.