Shape Patterns in Digital Fabrication: A Survey on Negative Poisson’s Ratio Metamaterials

Yılmaz, Bengisu
Adanova, Venera
Acar, Rüyam
Tarı, Zehra Sibel
Poisson’s ratio for solid materials is defined as the ratio of the lateral length shrinkage to the longitudinal part extension on a simple tension test. While Poisson’s ratio for almost every material in nature is a positive number, materials having negative Poisson’s ratio may be engineered. We survey computational works toward design and fabrication of negative Poisson’s ratio materials focusing on shape patterns from macro to micro scale. Specifically, we cover folding, knitting, and repeatedly ordering geometric structures, i.e., symmetry. Both pattern design and the numerical aspects of the problem yield various future research possibilities.


Nonlinearity of the residual shear strength envelope in stiff clays
Maghsoudloo, Arash; Huvaj Sarıhan, Nejan; Department of Civil Engineering (2013)
During shearing of stiff clays, plate-shaped clay particles are parallel-oriented in the direction of shear reaching the minimum resistance of “residual shear strength”. The residual shear strength envelopes of stiff clays are curved, but for practical purposes represented by linear envelopes. This study investigates the nonlinearity of the residual shear strength envelope using experimental evidence (i) from laboratory reversal direct shear tests on two stiff clays (Ankara clay and kaolinite) at 25 to 900 ...
Numerical Simulation of Reciprocating Flow Forced Convection in Two-Dimensional Channels
Sert, Cüneyt (ASME International, 2003-5-20)
<jats:p>Numerical simulations of laminar, forced convection heat transfer for reciprocating, two-dimensional channel flows are performed as a function of the penetration length, Womersley (α) and Prandtl (Pr) numbers. The numerical algorithm is based on a spectral element formulation, which enables high-order spatial resolution with exponential decay of discretization errors, and second-order time-accuracy. Uniform heat flux and constant temperature boundary conditions are imposed on certain regions of the ...
Optimum characteristic properties of isolators with bilinear force-displacement hysteresis for seismic protection of bridges built on various site soils
Dicleli, Murat (Elsevier BV, 2011-07-01)
In this study, closed form equations as functions of the isolator, bridge and ground motion properties are formulated to calculate the optimum characteristic strength, Q(d) and post-elastic stiffness, k(d), of the isolator to minimize the maximum isolator displacement (MID) and force (MIF) for seismic isolated bridges (SIBS). For this purpose, first, sensitivity analyses are conducted to identify the bridge, isolator and ground motion parameters that affect the optimum values of Q(d) and k(d). Next, for the...
Streamwise oscillations of a cylinder beneath a free surface: Free surface effects on fluid forces
Kocabiyik, Serpil; Bozkaya, Canan (2015-11-01)
A two-dimensional free surface flow past a circular cylinder forced to perform streamwise oscillations in the presence of an oncoming uniform flow is investigated at a Reynolds number of R=200 and fixed displacement amplitude, A=0.13, for the forcing frequency-to-natural shedding frequency ratios, f/f(0) = 1.5, 2.5, 3.5. The present two-fluid model is based on a velocity-pressure formulation of the two-dimensional continuity and unsteady Navier-Stokes equations. The continuity and Navier-Stokes equations ar...
ELSAID, M; Tomak, Mehmet (1991-02-01)
The binding energy for on-centre impurities in a rectangular quantum well wire is calculated as a function of the width of the wire and perpendicular magnetic field. The results for zero-magnetic-field cases are in perfect agreement with previous calculations.
Citation Formats
B. Yılmaz, V. Adanova, R. Acar, and Z. S. Tarı, Shape Patterns in Digital Fabrication: A Survey on Negative Poisson’s Ratio Metamaterials. 2018.