Karola Dierichs

Packings of 3D stars: stability and structure

We describe a series of experiments involving the creation of cylindrical packings of star-shaped particles, and an exploration of the stability of these packings. The stars cover a broad range of arm sizes and frictional properties. We carried out three different kinds of experiments, all of which involve columns that are prepared by raining star particles one-by-one into hollow cylinders. As an additional part of the protocol, we sometimes vibrated the column before removing the confining cylinder. We rate stability in terms of r, the ratio of the mass of particles that fall off a pile when it collapsed, to the total particle mass. The first experiment involved the intrinsic stability of the column when the confining cylinder was removed. The second kind of experiment involved adding a uniform load to the top of the column, and then determining the collapse properties. A third experiment involved testing stability to tipping of the piles. We find a stability diagram relating the pile height, h, versus pile diameter,

Simulation of Aggregate Structures in Architecture: Distinct-Element Modeling of Synthetic Non-convex Granulates

\delta

Modelling Aggregate Behaviour

δ, where the stable and unstable regimes are separated by a boundary that is roughly a power-law in h versus

Granular Morphologies: Programming Material Behaviour with Designed Aggregates

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Structure of hexapod 3D packings: understanding the global stability from the local organization

δ with an exponent that is less than unity. Increasing vibration and friction, particularly the latter, both tend to stabilize piles, while increasing particle size can destabilize the system under certain conditions.

Granular Construction: Designed Particles for Macro-Scale Architectural Structures

Loose, designed macro-scale granulates can be used as architectural material systems. Combined with a digitallycontrolled emitter-head the pouring process can serve as an alternative to known additive manufacturing techniques. The potential of macro-scale granulates lies in their ability to re-configure as well as in being a functionally graded material. Given that these loose granulates merely display probable rather than certain behavior, the use of responsive motion-planning becomes a critical aspect. The research presented here introduces the field of synthetically produced architectural granulates. An overview of the current state of the art of robotically poured granulates is given. Within this context, the proposed robotic pouring process for designed granulates is outlined. The established feedback loop consisting of optical sensing, parametric motion-planning, and robotic actuation is described in detail. In conclusion, an outlook for further research is given.