Development, characterization and analysis of auxetic structures from braided composites and study the influence of material and structural parameters

Abstract

Auxetic materials are gaining special interest in technical sectors due to their attractive mechanical behaviour. This paper reports a systematic investigation on missing rib design based auxetic structures produced from braided composites for civil engineering applications. The influence of various structural and material parameters on auxetic and mechanical properties was thoroughly investigated. The basic structures were also modified with straight longitudinal rods to enhance their strengthening potential in structural elements. Additionally, a new analytical model was proposed to predict Poisson's ratio through a semi empirical approach. Auxetic and tensile behaviours were also predicted using finite element analysis. The auxetic and tensile behaviours were observed to be more strongly dependent on their structural parameters than the material parameters. The developed analytical models could well predict the auxetic behaviour of these structures except at very low or high strains. Good agreement was also observed between the experimental results and numerical analysis.

Different Deformation Mechanisms Leading to Auxetic Behavior Exhibited by Missing Rib Square Grid Structures

“…The structure was originally proposed as an extension of the missing rib model based on the lozenge grid . However, while the missing rib lozenge grid continued to receive some attention the one based on the square grid much less so.…”

Electroconductive Melt Electrowritten Patches Matching the Mechanical Anisotropy of Human Myocardium

“…Using ζ = 80° and ϕ = 40° would result in a theoretical anisotropic ratio of effective stiffness of 2.01. We tessellated the missing-rib or lozenge grid as reported [42] ( Figure 1d). As a control design, we fabricated a square mesh with a positive Poisson's ratio (v = 1, Figure 1e).…”

A study of tubular braided structure with negative Poisson’s ratio behavior

“…48 In total, five different structures were fabricated by assembling the BCRs in the form of a 'missing rib' in the research. Later on, they conducted a systematic study on this auxetic structure to investigate influences of materials and structures 49 and proved that structures designed on a basis of 're-entrant' also exhibit the auxetic effect. 50 It is indicated that these attempts successfully developed macroscale auxetic structures from braided composites for the first time while the BCR itself is non-auxetic.…”