On the inclined static loading of honeycomb re-entrant auxetics. (1st October 2021)

• Record Type: Journal Article
• Authors: Dhari, Rahul Singh; Javanbakht, Zia; Hall, Wayne
• Is Part Of: Composite structures. Volume 273(2021)
• Publication Date: 2021-10-01
• Subjects: Metamaterial -- Computational mechanics -- Pushover analysis -- Nonlinear mechanism -- Plastic hinge; Composite construction -- Periodicals; Composites -- Périodiques; 624.18
• DOI: 10.1016/j.compstruct.2021.114289
• Languages: English
• ISSNs: 0263-8223

Abstract

Highlights: Energy efficiency of RH structures reaches a higher peak under inclined loads. Energy efficiency of RH structures is high at the early stages of uniform compression. Significant reduction in mean crushing force is observed for RH structures at inclined loads. A new transition stage is induced under inclined loads. New micro modes ('distorted X', and '>' modes) for RH structures emerge under inclined loads. Abstract: The present study unravels the deformation mechanisms observed during the static inclined compression of re-entrant honeycomb (RH) auxetic structure. A pushover Riks analysis is conducted by facing a rigid plate towards the structure at various angles. A new 'plastic hinge tracing method' is introduced to systematically extract the micro deformation mechanisms under inclined loading. The identified modes are related to the macro deformation regime and the overall mechanical response of the RH structure. Moreover, their relation to various measures of efficiency is elaborated. It is shown that a transition stage emerges under inclined loading, which delays achieving the peak energy efficiency. The overall energy dissipation decreases in the inclined cases but interestingly, the performance of the RH structure does not deteriorate. Namely by maintaining a low crushing force under inclined loads, the trade-off of low energy dissipation is balanced and a lower impact is anticipated. Finally, the similarities between the transition stage and the macro modes are highlighted and further directions for investigation are proposed.