scholarly journals Determination of shear modulus and Poisson's ratio of polymers and foams by the anticlastic plate-bending method

1997 ◽  
Vol 30 (6) ◽  
pp. 377-382 ◽  
Author(s):  
M. Farshad ◽  
M. W. Wildenberg ◽  
P. Flüeler
Keyword(s):  
Shear Modulus ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Plate Bending

In Situ Measurement of Poisson’s Ratio of Steel Plates During Thermal Processes Using Resonant Modes

2021 ◽  
Author(s):  
Clemens Grünsteidl ◽  
Christian Kerschbaummayr ◽  
Edgar Scherleitner ◽  
Bernhard Reitinger ◽  
Georg Watzl ◽  
...  
Keyword(s):  
Poisson’S Ratio ◽  
Dual Phase Steel ◽  
Steel Plates ◽  
Poisson's Ratio ◽  
Austenitic Phase ◽  
Resonant Modes ◽  
Longitudinal Sound Velocity ◽  
Contact Free

Abstract We demonstrate the determination of the Poisson’s ratio of steel plates during thermal processing based on contact free laser ultrasound measurements. Our method utilizes resonant elastic waves sustained by the plate, provides high amplitudes, and requires only a moderate detection bandwidth. For the analysis, the thickness of the samples does not need to be known. The trend of the measured Poisson’s ratio reveals a phase transformation in dual-phase steel samples. While previous approaches based on the measurement of the longitudinal sound velocity cannot distinguish between the ferritic and austenitic phase above 770°C, the shown method can. If the thickness of the samples is known, the method also provides both sound velocities of the material. The gained complementary information could be used to analyze phase composition of steel from low temperatures up to its melting point.

scholarly journals Effect of Temperature on Formaldehyde Diffusion in Cellulose Amorphous Region: A Simulation Study

BioResources ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. 3200-3213
Author(s):  
Wei Wang ◽  
Yancai Cao ◽  
Liyue Sun ◽  
Mingshuai Wu
Keyword(s):  
Shear Modulus ◽  
Bulk Modulus ◽  
Poisson’S Ratio ◽  
Amorphous Region ◽  
Poisson's Ratio ◽  
Effect Of Temperature ◽  
External Temperature ◽  
Practical Applications ◽  
Region Model ◽  
Materials Studio

A formaldehyde-cellulose amorphous region model at the micro-level was established using the molecular dynamics software Materials Studio to simulate the change of cellulose and formaldehyde molecules in an external temperature field. The diffusion coefficients of formaldehyde molecules increased as the temperature increased. Moreover, the total number of hydrogen bonds decreased, and the interaction energy in the formaldehyde-cellulose model was reduced, which confirmed this conclusion and indicated that temperature increase could enhance the diffusion of formaldehyde in cellulose. The mechanical parameters of cellulose were analyzed in terms of Young’s modulus, shear modulus, bulk modulus, Poisson’s ratio, and the ratio of bulk modulus to shear modulus (K/G), which were affected by the temperature. The elastic modulus (E, G, and K) of cellulose decreased as the temperature increased, while the Poisson’s ratio V and K/G values increased. The results of the research explain how elevated temperature can promote the release of formaldehyde in furniture from a microscopic perspective, which supports each other with the results of previous experimental data and practical applications in production.

Determination of poisson's ratio for polyimide films

1989 ◽  
Vol 29 (16) ◽  
pp. 1107-1110 ◽  
Author(s):  
C. L. Bauer ◽  
R. J. Farris
Keyword(s):  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
Polyimide Films

scholarly journals Temperature Variability of Poisson’s Ratio and Its Influence on the Complex Modulus Determined by Dynamic Mechanical Analysis

Technologies ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 81
Author(s):  
Vitor Carneiro ◽  
Helder Puga
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Poisson’S Ratio ◽  
Complex Modulus ◽  
Mechanical Analysis ◽  
Temperature Variability ◽  
Poisson's Ratio ◽  
Constant Frequency ◽  
Dynamic Mechanical ◽  
Characterization Of Materials

Dynamic mechanical analysis (DMA) is the usual technology for the thermomechanical viscoelastic characterization of materials. This method monitors the instant values of load and displacement to determine the instant specimen stiffness. Posteriorly, it recurs to those values, the geometric dimensions of the specimen, and Poisson’s ratio to determine the complex modulus. However, during this analysis, it is assumed that Poisson’s ratio is constant, which is not always true, especially in situations where the temperature can change and promote internal modification in the specimens. This study explores the error that is imposed in the results by the determination of the real values of complex moduli due to variable Poisson’s ratios arising from temperature variability using a constant frequency. The results suggest that the evolution of the dynamic mechanical analysis should consider the Poisson’s ratio input as a variable to eliminate this error in future material characterization.

Sign in / Sign up

Export Citation Format

Share Document