کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
278074 1430274 2012 15 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Planar isotropic structures with negative Poisson’s ratio
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی عمران و سازه
پیش نمایش صفحه اول مقاله
Planar isotropic structures with negative Poisson’s ratio
چکیده انگلیسی

A new design principle is suggested for constructing auxetic structures – the structures that exhibit negative Poisson’s ratio (NPR) at macroscopic level. We propose 2D assemblies of identical units made of a flexible frame with a sufficiently rigid reinforcing core at the centre. The core increases the frame resistance to the tangential movement thus ensuring high shear stiffness, whereas the normal stiffness is low being controlled by the local bending response of the frame. The structures considered have hexagonal symmetry, which delivers macroscopically isotropic elastic properties in the plane perpendicular to the axis of the symmetry. We determine the macroscopic Poisson’s ratio as a ratio of corresponding relative displacements computed using the direct microstructural approach. It is demonstrated that the proposed design can produce a macroscopically isotropic system with NPR close to the lower bound of −1. We also developed a 2D elastic Cosserat continuum model, which represents the microstructure as a regular assembly of rigid particles connected by elastic springs. The comparison of values of NPRs computed using both structural models and the continuum approach shows that the continuum model gives a healthy balance between the simplicity and accuracy and can be used as a simple tool for design of auxetics.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: International Journal of Solids and Structures - Volume 49, Issue 17, 1 September 2012, Pages 2239–2253
نویسندگان
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