Design of a Meta-Material with Targeted Nonlinear Deformation Response
CHALLENGE - A new method is needed to optimize meta-material unit cells using engineering principles to achieve the desired nonlinear response. The M1 Abrams tank contains track pads that consist of a high density rubber. This rubber fails prematurely due to heat buildup caused by the hysteretic nature of elastomers. The goal is to replace this elastomer by a meta-material that has equivalent nonlinear deformation characteristics without primary failure.
SOLUTION - A method was developed called the Unit Cell Synthesis Method, that requires the designer to have a fundamental understanding of the geometric nonlinearity of an elemental geometry. One or more of these elemental geometries are then systematically combined into a unit cell. A size optimization is performed on promising unit cell concepts to tune the geometry and converge its response towards that of the target. The optimization routine was carried out in modeFRONTIER to optimize the input Unit Cell (UC) parameters. These UC parameters were input to a Python script that assembled the appropriate 4x4 BrickOval meta-material, applied the load and boundary conditions, generated a mesh, and performed a finite element analysis for all four load cases in Abaqus.
BENEFITS - A Python script was used in a modeFRONTIER optimization routine to optimize the dimensions of the BrickOval Unit Cell (UC) design. The meta-material that was designed in this work demonstrated it was possible to design a meta-material to match a nonlinear deformation response. This was a previously unexplored area and therefore expands the knowledge in meta-material design and its potential applications.