scholarly journals Universal Scaling Laws of Origami Paper Springs

Author(s):  
Bohua Sun

This letter solves an open question of paper spring risen by Yoneda (2019). Universal scaling laws of a paper spring are proposed by using both dimensional analysis and data fitting. It is found that spring force obeys power square law of spring extension, however strong nonlinear to the total twist angle. Without doing any additional works, we have successfully generalize the scaling laws for Poisson ratio 0.3 to the materials with an arbitrary Poisson's ratio with the help of dimensional analysis.

Geophysics ◽  
1982 ◽  
Vol 47 (5) ◽  
pp. 819-824 ◽  
Author(s):  
Harsh K. Gupta ◽  
Ronald W. Ward ◽  
Tzeu‐Lie Lin

Analysis of P‐ and S‐waves from shallow microearthquakes in the vicinity of The Geysers geothermal area, California, recorded by a dense, telemetered seismic array operated by the U.S. Geological Survey (USGS) shows that these phases are easily recognized and traced on record sections to distances of 80 km. Regional average velocities for the upper crust are estimated to be [Formula: see text] and [Formula: see text] for P‐ and S‐waves, respectively. Poisson’s ratio is estimated at 23 locations using Wadati diagrams and is found to vary from 0.13 to 0.32. In general, the Poisson’s ratio is found to be lower at the locations close to the steam production zones at The Geysers and Clear Lake volcanic field to the northeast. The low Poisson ratio corresponds to a decrease in P‐wave velocity in areas of high heat flow. The decrease may be caused by fracturing of the rock and saturation with gas or steam.


2013 ◽  
Vol 781-784 ◽  
pp. 799-802
Author(s):  
Fei Dai ◽  
Wu Yun Zhao ◽  
Zheng Sheng Han ◽  
Feng Wei Zhang

Poisson's ratio is one of the important physical parameters in the finite element calculation model of corn kernel. In this study, through the preparation of the test material and test program design, with the loading speed of the testing machine was 2mm/min, through applied different loading (30N, 90N, 120N and 150N) for Poisson's ratio determination about corn kernel with the experiment. The test results showed that the Poisson's ratio average value in 0.399-0.423 when the corn kernel moisture content was 13.2%, the greater loading was applied, and the smaller value in the fluctuation range of the Poisson's ratio was measured. When applied to the indenter loading of 150N, the corn kernel Poisson ratio fluctuation which was between the minimum and maximum value of 5.1%.


Author(s):  
Bohua Sun

The hydraulic fracturing is studied by using dimensional analysis. A universal scaling law of the hydraulic fracturing is obtained. This simple relation has not been seen in the literature.


1969 ◽  
Vol 42 (2) ◽  
pp. 547-556 ◽  
Author(s):  
H. Sekiguchi ◽  
M. Kakiuchi ◽  
T. Morimoto ◽  
K. Fujimoto ◽  
N. Yoshimura

Abstract Changes in the Poisson's ratio of natural vulcanized rubber due to elongation were investigated experimentally. The following results were obtained: If infinitesimal deformation at any instant during elongation is considered, it appears to be correct to take the Poisson's ratio at such instants as 0.5. If the apparent Poisson ratio when a certain standard mark is taken and a large deformation imparted is considered, and the elongation ratio is made α, the Poisson's ratio decreases from 0.5 in accordance with the equation log10 (1/m)=0.0204α2−0.261α−0.0628. This equation is valid for subsequent elongations, no matter what elongation situation is taken for the standard marks. These two results do not vary with the carbon black content or on repeated stretching.


Author(s):  
Bohua Sun

By using directed dimensional analysis and data fitting, an explicit universal scaling law for the velocity of dominoes toppling motion is formulated. The scaling law shows that domino propagational velocity is linearly proportional to the $1/2$ power of domino separation and thickness, and $-1/2$ power of domino height and gravitation. The study also proved that dominoes width and mass have no influence on the domino wave traveling velocity. The scaling law obtained in this Letter is very useful to the dominoes game and will help the domino player to place the dominoes for fast speed and have a quick estimation on the speed without doing complicated multi-bodies dynamical simulation.


2021 ◽  
Vol 263 (3) ◽  
pp. 3790-3794
Author(s):  
Lucie Rouleau ◽  
Isadora Ruas Henriques ◽  
Jean-François Deü

An efficient way of mitigating noise and vibration is to embed viscoelastic patches into the host structure. Viscoelastic properties are of significant importance in determining the performance of the passive damping treatment. The behaviour of homogeneous isotropic materials is described by two elastic constants (generally the Young modulus and the Poisson ratio, or the shear and bulk moduli), which are frequency- and temperature-dependent in the case of viscoelastic materials. In practice, the Poisson's ratio is often considered as independent of temperature and frequency. One goal of this work is to numerically evaluate the validity of this assumption and its limitations (frequency range, thickness of the viscoelastic layer). To this end, a thermo-mechanical characterization of a viscoelastic material is carried out by dynamic measurements of the complex shear and bulk moduli, allowing the indirect measurement of the frequency- and temperature-dependent Poisson's ratio. Moreover, the measurements of the Poisson's ratio (direct or indirect) can lead to considerable uncertainties. For instance, large discrepancies have been observed when characterizing the Poisson's ratio of polymer foams. Another goal of this work is to investigate the influence of those uncertainties on the dynamic response of a damped structure.


2016 ◽  
Vol 78 (5-2) ◽  
Author(s):  
Rohana Hassan ◽  
Syed Syazaril Amri Syed Mubarat ◽  
Anizahyati Alisibramulisi

Young’s Modulus and Poisson’s ratio are the mechanical properties that need to be determined for the production of engineering design or information for the numerical analysis of timber. In this study, Merpauh, Kapur and Sesenduk species were selected. This experimental investigation focuses on the elastic properties of those timber species. The Modulus of Elasticity (MOE) and Poisson’s ratio were determined by means of tensile tests. In addition, Modulus of Rigidity (MOR), tensile strength capacity and its moisture contents were also determined. The deformation during testing was measured by means of mechanical extensometer. The MOE of the studied species range from 36.7 N/mm2 to 119.2 N/mm2, whereas Poisson’s ratio values show less variability. The result of the study also shows that the mechanical properties for the species are related. The larger the density value, the larger value of stress and strain will be. Thus, the value of Poisson ratio will also increase, respectively.


Author(s):  
Bohua Sun

By using directed dimensional analysis and data fitting, an explicit universal scaling law for the speed of falling dominoes is formulated. The scaling law shows that domino propagational speed is linear proportional to the 3/2 power of domino separation, and -1/2 power of domino height and thickness.


Author(s):  
Bohua Sun

By using directed dimensional analysis and data fitting, an explicit universal scaling law for the velocity of dominoes toppling motion is formulated. The scaling law shows that domino propagational velocity is linear proportional to the 3/2 power of domino separation, and -1/2 power of domino height and thickness. The study also proved that dominoes width and mass have no influence to the domino wave traveling velocity.


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