We have investigated the buckling and snapping unstabilities of beams with a slit, both experimentally and numerically, for different geometries. We find that beams with a slit display non-linear...Show moreWe have investigated the buckling and snapping unstabilities of beams with a slit, both experimentally and numerically, for different geometries. We find that beams with a slit display non-linear symmetry breaking. Specifically they display asymmetric buckled states after symmetrically buckling, a property that can be used in metamaterial design to propagate and amplify symmetry breaking perturbations. We find hysteresis between the "closed" and "open" post-buckling states of the beam and that the transitions between these are snappy. This hysteresis implies that, under compression, these beams are tristable. Exploring two of the states connected by a hysterectic transition, we can regard them as hysterons under a compression field. We find that we can tune the degree of asymmetry as well as the regime where there is hysteresis by modifying the geometrical parameters of the beam. Both the non-linear symmetry breaking and its characteristic as hysterons make beams with a slit useful tools to achieve functionality in metamaterial design.Show less
In this thesis we will demonstrates how to construct a counting mechanical metamate- rial that is based on bi-stable buckling beams by creating a material that can count to ten. By coupling...Show moreIn this thesis we will demonstrates how to construct a counting mechanical metamate- rial that is based on bi-stable buckling beams by creating a material that can count to ten. By coupling bistable buckling beams in a suitable geometry we can design mate- rials that when cyclically compressed between two critical strains. We show that when two adjacent buckled beams touch, there is a characteristic length scale - the inversion length - that determines which of two beams snaps through when compressed to the snapping strain. We experimentally and analytically work out the characteristic inver- sion distance length scale that determines the outcome of the battle of the buckling beams and show how to modify beam geometries to design counting behaviour for many beam materials.Show less
In this thesis we investigate the effects of bending on a Miura Ori Origami sheet. In particular we are going to analyse a simplified version, a single stripe made by a row of unit cells. We will...Show moreIn this thesis we investigate the effects of bending on a Miura Ori Origami sheet. In particular we are going to analyse a simplified version, a single stripe made by a row of unit cells. We will investigate how the bending stiffness and the curvature at the surface are changing with the variation of the fold angle of the structure and with the application of an external force. We investigate the curvature by scanning the samples with a 3D scanner and then analysing the data. To probe the bending stiffness, we use an Instron, a uniaxial compression device.Show less
We report the design and construction of a mechanism, consisting of rigid plates and freely hinging connectors, that is used to describe and study the motions of a mechanical metamaterial called...Show moreWe report the design and construction of a mechanism, consisting of rigid plates and freely hinging connectors, that is used to describe and study the motions of a mechanical metamaterial called the ‘metacube’. For this design, a novel method is used, where the mechanism is 3D printed and the accuracy is mechanically tested. We present an accurate mechanism that describes the motions of the metacube. This mechanism can be used to not only gain further understanding of the properties of the metacube, but also shows previously undiscovered properties of this mechanical metamaterial.Show less
