Laser-ultrasonic measurements of the elastic properties of a static and a moving paper web and of the web tension

2001 ◽  
Author(s):  
Alain Blouin
Keyword(s):  
Elastic Properties ◽  
Laser Ultrasonic ◽  
Ultrasonic Measurements ◽  
The Web ◽  
Web Tension

Laser ultrasonic measurements to estimate the elastic properties of rock samples underin situconditions

2019 ◽  
Vol 90 (11) ◽  
pp. 114503 ◽  
Author(s):  
Jonathan Simpson ◽  
Kasper van Wijk ◽  
Ludmila Adam ◽  
Caitlin Smith
Keyword(s):  
Elastic Properties ◽  
Laser Ultrasonic ◽  
Rock Samples ◽  
Ultrasonic Measurements

scholarly journals Picosecond laser ultrasonic measurements of interlayer elastic properties of 2H-MoSe2 and 2H-WSe2

2020 ◽  
Vol 18 ◽  
pp. 100369
Author(s):  
E. Thompson ◽  
E. Manzella ◽  
E. Murray ◽  
M. Pelletier ◽  
J. Stuligross ◽  
...  
Keyword(s):  
Elastic Properties ◽  
Picosecond Laser ◽  
Laser Ultrasonic ◽  
Ultrasonic Measurements

scholarly journals Upscaling of elastic properties in carbonates: A modeling approach based on a multiscale geophysical data set

2020 ◽  
Author(s):  
Jerome Fortin ◽  
Cedric Bailly ◽  
Mathilde Adelinet ◽  
Youri Hamon
Keyword(s):  
Elastic Properties ◽  
Wave Velocity ◽  
Representative Elementary Volume ◽  
P Wave ◽  
Elementary Volume ◽  
Data Set ◽  
Wave Velocities ◽  
P Wave Velocity ◽  
Ultrasonic Measurements ◽  
Seismic Scale

<p>Linking ultrasonic measurements made on samples, with sonic logs and seismic subsurface data, is a key challenge for the understanding of carbonate reservoirs. To deal with this problem, we investigate the elastic properties of dry lacustrine carbonates. At one study site, we perform a seismic refraction survey (100 Hz), as well as sonic (54 kHz) and ultrasonic (250 kHz) measurements directly on outcrop and ultrasonic measurements on samples (500 kHz). By comparing the median of each data set, we show that the P wave velocity decreases from laboratory to seismic scale. Nevertheless, the median of the sonic measurements acquired on outcrop surfaces seems to fit with the seismic data, meaning that sonic acquisition may be representative of seismic scale. To explain the variations due to upscaling, we relate the concept of representative elementary volume with the wavelength of each scale of study. Indeed, with upscaling, the wavelength varies from millimetric to pluri-metric. This change of scale allows us to conclude that the behavior of P wave velocity is due to different geological features (matrix porosity, cracks, and fractures) related to the different wavelengths used. Based on effective medium theory, we quantify the pore aspect ratio at sample scale and the crack/fracture density at outcrop and seismic scales using a multiscale representative elementary volume concept. Results show that the matrix porosity that controls the ultrasonic P wave velocities is progressively lost with upscaling, implying that crack and fracture porosity impacts sonic and seismic P wave velocities, a result of paramount importance for seismic interpretation based on deterministic approaches.</p><p>Bailly, C., Fortin, J., Adelinet, M., & Hamon, Y. (2019). Upscaling of elastic properties in carbonates: A modeling approach based on a multiscale geophysical data set. Journal of Geophysical Research: Solid Earth, 124. https://doi.org/10.1029/2019JB018391</p>

Modeling of Web Slip on a Roller and Its Effect on Web Tension Dynamics

2005 ◽  
Author(s):  
Ramamurthy V. Dwivedula ◽  
Prabhakar R. Pagilla
Keyword(s):  
Numerical Computation ◽  
Dynamic Models ◽  
Simple Approach ◽  
Roller Surface ◽  
Perfect Adhesion ◽  
The Web ◽  
Web Tension

This paper considers the effect of web slip over the rollers on the span tension dynamics. In classical development of the web span tension dynamics, it is assumed that there is strict adhesion between the web and the surface of the roller and thus, there is no slip-page between the web and the roller. As a result of this assumption, effect of tension disturbances in downstream spans on the upstream span tension is precluded. However, in practice, perfect adhesion between the web and roller surface is seldom achieved and tension disturbances propagate upstream also. Though web span tension dynamic models that include slippage between web and roller are proposed, these models rely to a great extent on numerical computation of slip arc angles and are prohibitively complex to be of practical use. This paper proposes an alternative, simple approach for developing web span tension dynamics to include the effect of web slip.

Laser ultrasonic investigation of the elastic properties of unidirectional graphite-epoxy composites

1998 ◽  
Vol 34 (6) ◽  
pp. 575-582 ◽  
Author(s):  
A. A. Karabutov ◽  
I. M. Kershtein ◽  
I. M. Pelivanov ◽  
N. B. Podymova
Keyword(s):  
Elastic Properties ◽  
Epoxy Composites ◽  
Laser Ultrasonic ◽  
Ultrasonic Investigation

Advanced Optimization of Industrial Large-Scale Roll-to-Roll Systems Under Parametric Uncertainties

2012 ◽  
Author(s):  
J. Frechard ◽  
D. Knittel
Keyword(s):  
Young’S Modulus ◽  
Large Scale ◽  
Young's Modulus ◽  
Robust Design Optimization ◽  
Parametric Uncertainties ◽  
Optimization Approach ◽  
Roll To Roll ◽  
Polymer Metal ◽  
The Web ◽  
Web Tension

In industrial plants some parameters can not be evaluated properly or they are varying with time. These parametric uncertainties has to be taken into account during the design process of industrial systems. In this work, the developped optimization approach is applied on an industrial roll-to-roll sytem. Such systems are commonly used to handle materials as polymer, metal, paper and textile. The key challenge is to move the web at the expected speed while maintaining the web tension in an acceptable range around its reference. Moreover, the Young’s modulus of the web is difficult to evaluate and it is varying with time due to temperature and moisture variations. This paper deals with the web tension controller synthesis on a large-scale roll-to-roll system with uncertain Young’s modulus. To synthesize web tension controllers, an H∞ approach is applied and adapted to the system with parametric uncertainties using multi-objective robust design optimization.

Sign in / Sign up

Export Citation Format

Share Document