Year-end Sale % OFF 
Abstract
This research presents an investigation of the compressive behavior of auxetic cementitious cellular composites (CCCs) using a combination of experiments and finite element (FE) simulations. Typical auxetic centrosymmetric geometry was used as unit cells for the cellular structure and fiber reinforced cementitious mortar were used as constituent material. By varying the cellular geometry, three CCCs (P0, P25 and P50) were prepared then experimentally and numerically tested under uniaxial compression with different boundary conditions. Good agreement can be found between experimental and FE simulated results: Only CCCs with chiral section (P25 and P50) exhibited auxetic behavior and a typical compressive stress–strain response with two peaks was found; Under restrained boundary condition, different from the cone confinement zone observed in bulk cementitious materials, re-entrant confinement zone was found in the auxetic CCCs. More importantly, a cracking initiated section rotation mechanism is identified for the CCCs’ auxetic behavior which is distinct from the elastic instability mechanism of polymeric auxetic materials with the same cellular structure. In terms of density, energy dissipation ability and Poisson’s ratio, the auxetic CCCs shows excellent properties making them promising in various civil engineering applications.
Highlights
The term ‘‘auxetic”, first coined by Evans [1] in 1990 s, refers to materials exhibiting negative Poisson’s ratio (NPR)
Compared to conventional continuum solids, auxetic materials possess outstanding advantages regarding their mechanical properties in several aspects: on one hand, the cellular structure constructed by periodic unit cells affords them considerably lower weight [18,19,20] comparing to continuum solids
The same method described in [28] was adopted to prepare cementitious cellular composites (CCCs) specimens: the designed cellular structures were 3D printed by a commercial fused deposition modelling (FDM) based 3D printer Ultimaker 2 + using acrylonitrile butadiene styrene (ABS) material
Summary
The term ‘‘auxetic”, first coined by Evans [1] in 1990 s, refers to materials exhibiting negative Poisson’s ratio (NPR). The adopted centrosymmetric chiral structures by [27,28] are usually identified as ‘‘elastic-instability” structures in which the auxetic mechanism is attributed to elastic buckling In this sense, materials with high deformability, such as polymeric materials, are often used for this type of structures to achieve auxetic behavior. For auxetic cementitious materials, because of the NPR lateral contraction instead of expansion is restrained by the loading plates and the frictional restraining force direction is inverted In this sense, the influence of boundary restraint on the compressive behavior of the auxetic cementitious materials may be rather different. Programming cellular structures of the auxetic cementitious materials makes a new material developing strategy which, requires a rational understanding on the NPR mechanism, the impact of geometrical features and boundary conditions on the mechanical behavior of auxetic materials. With regard to the NPR mechanism, the influence of geometrical features and boundary conditions on the mechanical properties of the auxetic CCCs, analyses coupling experiment and numerical simulation were performed
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
