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arXiv · 1510.05716

Freestanding loadbearing structures with Z-shaped particles

Kieran A. Murphy·Nikolaj Reiser·Darius Choksy·Clare E. Singer·Heinrich M. Jaeger
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Abstract

Architectural structures such as masonry walls or columns exhibit a slender verticality, in contrast to the squat, sloped forms obtained with typical unconfined granular materials. Here we demonstrate the ability to create freestanding, weight-bearing, similarly slender and vertical structures by the simple pouring of suitably shaped dry particles into a mold that is subsequently removed. Combining experiments and simulations we explore a family of particle types that can entangle through their non-convex, hooked shape. We show that Z-shaped particles produce granular aggregates which can either be fluid and pourable, or solid and rigid enough to maintain vertical interfaces and build freestanding columns of large aspect ratio (>10) that support compressive loads without external confinement. We investigate the stability of such columns with uniaxial compression, bending, and vibration tests and compare with other particle types including U-shaped particles and rods. We find a pronounced anisotropy in the internal stress propagation together with strong strain-stiffening, which stabilizes rather than destabilizes the structures under load.

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Kieran A. Murphy, Nikolaj Reiser, Darius Choksy, Clare E. Singer, Heinrich M. Jaeger. 2015-10-19. Freestanding loadbearing structures with Z-shaped particles. https://arxiv.org/abs/1510.05716

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