Optimization of Origami Inspired Static and Active Mechanical Metamaterial

Origami-inspired materials provide effective solutions to control the mechanical properties of sandwich core structures, due to their outstanding structural features and due to the unique capacity of elastic deformation of its elements that are able to fold and unfold at different scales during the loading process. Both the geometrical features and the properties of the parent material that used to produce the origami structures are the most important factors required for tailoring the designed origami core with the target application. To eliminate the fracture and the abrupt stress change in the designed origami core elements, it is important to consider the parent material properties and behavior. There are two important challenges that should be considered in designing origami cores, the geometrical features of the origami tessellation and the material used to produce the origami unit cells and cores. Three dimensional origami cores can be fabricated by folding two dimensional flat sheets into three dimensional cores, or by pre-folding the origami features using a molding process. This research is devoted to investigate pre-folded origami cores made of polymeric materials for damping applications. Both passive and active properties of the designed unit cells were investigated in this research. Two different origami patterns were considered in the research, Miura and Ron-Resch-like origami structures. Different material blends were used to fabricate pre-folded origami features and correlate with the mechanical properties of the fabricated cores. Another way of preparing pre-folded origami cores is by using fused deposition modeling, in which different Ron-Resch-like cores with different geometrical parameters were designed and characterized for compression and impact load absorption. The designed origami cores were numerically simulated and compared with the experimental results. This motivated to include the viscoelastic behavior of the polymeric parent material at elevated temperature and simulate the cores’ unit cell using periodic boundary condition; the actual skeleton of the origami unit cell structure was represented in order to capture the mechanical behavior.Ph.D.2021-07-21 00:00:0