Jeudi 17 octobre à 11h, amphi Fermi ; IUSTI.
Abstract: Thin objects are easy to deform, as we see in everyday life: a piece of paper crumples, while an umbrella may invert in the wind. It is also clear that such thin structures choose to bend, rather than compress, whenever possible. Gauss’ "Remarkable Theorem” restricts how such pure bending deformations can happen, and its consequences are everywhere from pizza slices to the domed roofs of buildings, as well as many plants. I’ll discuss the limits of this stiffening to gravity, as well as how this geometrical stiffening can work for in some simple cases motivated by plants (the broad leaf lady palm), especially when they subject to water stress. I’ll also show that a small, but finite, thickness can cause snap-through (as seen in the Venus flytrap) but that the dynamics of this can be surprising.