Thermal relaxation of laminated bamboo for folded shells

•Localised heating promotes elasto-plastic behaviour in laminated bamboo.•Study of bamboo thermal relaxation behaviour applied to heat bending.•Method was demonstrated for folded helical shell composed of laminated bamboo.

Laminated bamboo is emerging as a novel material in design and construction. As a natural fibre composite, it has unique mechanical properties that allow for innovations that are not possible in other materials. Here, we discuss one new application of those properties: the development of a novel bending technique using high temperature, and we explore its implications for design. We have explored the fundamental properties of laminated bamboo and its thermal relaxation as it passes the glass transition temperatures of its constituent polymers. By mechanically thinning engineered bamboo material, score lines allow precise, controlled and localised heating that promotes limited but essential elasto-plastic behaviour. Concentrated heating above the glass transition temperature induces property evolution and structural morphology changes, which results in thermal relaxation with minimal recovery and full set upon cooling. This original technology is then deployed in the design and construction of a folded plate helical shell composed of thin laminated bamboo sheets.

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