An Optical Interference Method of Measuring Young's Modulus for Rods

1924 ◽  
Vol 22 (3) ◽  
pp. 475-480 ◽  
Author(s):  
G. F. C. Searle
Keyword(s):  
Cast Iron ◽  
Young’S Modulus ◽  
Cross Section ◽  
Young's Modulus ◽  
Circular Cross Section ◽  
Interference Method ◽  
Optical Interference ◽  
Iron Base ◽  
General Arrangement ◽  
Metal Plates

The general arrangement of the apparatus is shown in Fig. 1. A vertical steel rod AA of circular cross-section is fixed to a heavy cast-iron base Z shown diagrammatically in the figure. The rod AA is bent by a load applied to the end of the horizontal bar BC carried by the upper end of A A. The point of application of the load is defined by a transverse groove cut in the bar. The rod AA passes through the two metal plates DD, FF, which are soldered to the rod, the faces of these plates being horizontal.

scholarly journals Optimized CNT-PDMS Flexible Composite for Attachable Health-Care Device

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4523 ◽  
Author(s):  
Jian Du ◽  
Li Wang ◽  
Yanbin Shi ◽  
Feng Zhang ◽  
Shiheng Hu ◽  
...  
Keyword(s):  
Composite Material ◽  
Percolation Threshold ◽  
Young’S Modulus ◽  
Cross Section ◽  
Young's Modulus ◽  
Large Strain ◽  
Weight Ratio ◽  
Linear Range ◽  
Wide Range ◽  
The Cross

The CNT-PDMS composite has been widely adopted in flexible devices due to its high elasticity, piezoresistivity, and biocompatibility. In a wide range of applications, CNT-PDMS composite sensors were used for resistive strain measurement. Accordingly, the percolation threshold 2%~4% of the CNT weight ratio in the CNT-PDMS composite was commonly selected, which is expected to achieve the optimized piezoresistive sensitivity. However, the linear range around the percolation threshold weight ratio (2%~4%) limits its application in a stable output of large strain (>20%). Therefore, comprehensive understanding of the electromechanical, mechanical, and electrical properties for the CNT-PDMS composite with different CNT weight ratios was expected. In this paper, a systematic study was conducted on the piezoresistivity, Young’s modulus, conductivity, impedance, and the cross-section morphology of different CNT weight ratios (1 to 10 wt%) of the CNT-PDMS composite material. It was experimentally observed that the piezo-resistive sensitivity of CNT-PDMS negatively correlated with the increase in the CNT weight ratio. However, the electrical conductivity, Young’s modulus, tensile strength, and the linear range of piezoresistive response of the CNT-PDMS composite positively correlated with the increase in CNT weight ratio. Furthermore, the mechanism of these phenomena was analyzed through the cross-section morphology of the CNT-PDMS composite material by using SEM imaging. From this analysis, a guideline was proposed for large strain (40%) measurement applications (e.g., motion monitoring of the human body of the finger, arm, foot, etc.), the CNT weight ratio 8 wt% was suggested to achieve the best piezoresistive sensitivity in the linear range.

Quasistatic Model for the Symmetrical Ring Spinning Triangle

2011 ◽  
Vol 331 ◽  
pp. 498-501
Author(s):  
Xin Jin Liu ◽  
Xu Zhong Su ◽  
Ting Ting Wu
Keyword(s):  
Theoretical Model ◽  
Young’S Modulus ◽  
Cross Section ◽  
Young's Modulus ◽  
Force Balance ◽  
Ring Spinning ◽  
Torsion Moment ◽  
Fiber Tension ◽  
Convergence Point ◽  
Spinning Triangle

In this paper, theoretical model of the distribution of fiber tension in the symmetrical spinning triangle was given firstly. Then, based on the force balance of the twisting point, the quasistatic model for the symmetrical ring spinning triangle was present. It is shown that the convergence point can be determined with ease for different spinning tension, torsion moment, the numbers of fibers at the roller nip, the fiber tensile Young’s modulus and cross-section, and the width of the spinning triangle.

Elastic Properties of Normal and Binormal Helical Nanowires

2006 ◽  
Vol 963 ◽  
Author(s):  
Alexandre Fontes da Fonseca ◽  
C P Malta ◽  
Douglas S Galvão
Keyword(s):  
Simple Model ◽  
Young’S Modulus ◽  
Elastic Properties ◽  
Cross Section ◽  
Young's Modulus ◽  
Helical Axis ◽  
Geometric Features ◽  
Kirchhoff Rod ◽  
Rod Model ◽  
The Cross

ABSTRACTA helical nanowire can be defined as being a nanoscopic rod whose axis follows a helical curve in space. In the case of a nanowire with asymmetric cross section, the helical nanostructure can be classified as normal or binormal helix, according to the orientation of the cross section with respect to the helical axis of the structure. In this work, we present a simple model to study the elastic properties of a helical nanowire with asymmetric cross section. We use the framework of the Kirchhoff rod model to obtain an expression relating the Hooke's constant, h, of normal and binormal nanohelices to their geometric features. We also obtain the Young's modulus values. These relations can be used by experimentalists to evaluate the elastic properties of helical nanostructures. We showed that the Hooke's constant of a normal nanohelix is higher than that of a binormal one. We illustrate our results using experimentally obtained nanohelices reported in the literature.

scholarly journals Determination of Young’s modulus of Sb2S3 nanowires by in situ resonance and bending methods

2016 ◽  
Vol 7 ◽  
pp. 278-283 ◽  
Author(s):  
Liga Jasulaneca ◽  
Raimonds Meija ◽  
Alexander I Livshits ◽  
Juris Prikulis ◽  
Subhajit Biswas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Young’S Modulus ◽  
Cross Section ◽  
Young's Modulus ◽  
Cross Sectional ◽  
Bending Tests ◽  
Young’S Moduli ◽  
Increasing Trend

In this study we address the mechanical properties of Sb2S3 nanowires and determine their Young’s modulus using in situ electric-field-induced mechanical resonance and static bending tests on individual Sb2S3 nanowires with cross-sectional areas ranging from 1.1·104 nm2 to 7.8·104 nm2. Mutually orthogonal resonances are observed and their origin explained by asymmetric cross section of nanowires. The results obtained from the two methods are consistent and show that nanowires exhibit Young’s moduli comparable to the value for macroscopic material. An increasing trend of measured values of Young’s modulus is observed for smaller thickness samples.

Compression properties of vascular boundles and parenchyma of rattan (Plectocomia assamica Griff)

Holzforschung ◽  
2014 ◽  
Vol 68 (8) ◽  
pp. 927-932 ◽  
Author(s):  
Xing’e Liu ◽  
Genlin Tian ◽  
Lili Shang ◽  
Shumin Yang ◽  
Zehui Jiang
Keyword(s):  
Young’S Modulus ◽  
Cross Section ◽  
Compression Strength ◽  
Young's Modulus ◽  
Vascular Bundles ◽  
Mechanical Compression ◽  
Compression Tests ◽  
Compression Properties ◽  
Parenchyma Cells ◽  
Different Parts

Abstract Rattan is a unique unidirectional vascular bundles-reinforced biocomposite with many nodes along its canes. Mechanical compression tests have been performed from rattan samples taken from different parts of the cross section. Compression strength increased with increasing amounts of vascular bundles (VBs) in the tissues was investigated. Samples including the outer ring with many VBs have the highest apparent Young’s modulus of 1.08 GPa and the highest compression strength of 17.6 MPa. However, samples consisting of parenchyma cells had an apparent Young’s modulus of 25 MPa, and the compression strength of 1.81 MPa. The compression properties of core samples improved with increasing amounts of VB. The apparent Young’s modulus and compression strength of a single VB were 730 MPa and 6.87 MPa, respectively, and were calculated according to the rule of mixture of composites.

Vibration of Zinc Oxide Nanowires in Electric Field

2017 ◽  
Author(s):  
Lifeng Wang ◽  
Saisai Liu ◽  
Jianpeng Yi
Keyword(s):  
Electric Field ◽  
Young’S Modulus ◽  
Cross Section ◽  
Md Simulation ◽  
Young's Modulus ◽  
Continuum Theory ◽  
Zno Nanowires ◽  
Vibration Frequencies ◽  
Polarization Direction ◽  
The Cross

This paper studies the vibration of Zinc oxide (ZnO) nanowires in electric field via molecular dynamics (MD) simulation and continuum beam models. First, the size effects of the equivalent Young’s modulus and piezoelectric constant of ZnO nanowires are obtained by MD simulation and characterized by core-shell model. The piezoelectric constants of ZnO nanowires decrease with the rising of the size of cross section. The equivalent tensile and bending Young’s modulus of ZnO nanowires in polarization direction increases with the increasing of the cross section size. The equivalent tensile and bending Young’s modulus in polarization direction predicted by core-shell model is in good agreement with MD simulation. Then, the vibration of the cantilevered ZnO nanobeam is simulated by MD. When the cross section size becomes larger, the vibration frequencies predicted by continuum theory coincide with those obtained by MD simulation better. Finally, the effect of electric field on vibration frequency of a ZnO nanowire is studied by MD simulation and continuum beam models. It is found that the natural frequencies rise with the increasing of electric field for the case of positive electric field in polarization direction. But the natural frequencies will decrease with the increasing of negative electric field when the intensity of the electric field is relatively weak. The natural frequency is hard to be obtained when the phase transition is occurring in relatively strong negative electric field. The vibration frequencies of the cantilevered Timoshenko beam with axial force due to the effects of electric field are obtained. The frequencies obtained by Timoshenko beam model agree with MD results very well. The vibration frequencies of the continuum theory agree with MD results better when the size of the cross section increases. The vibration frequencies of the ZnO nanowire keep constant when the direction of electric field is perpendicular to the polarization direction.

Sign in / Sign up

Export Citation Format

Share Document