Determination of internal mechanical characteristics of woven fabrics using the force-balance analysis of yarn pullout test

2008 ◽  
Vol 99 (1) ◽  
pp. 47-55 ◽  
Author(s):  
M. Valizadeh ◽  
S. A.H. Ravandi ◽  
M. Salimi ◽  
M. Sheikhzadeh
Keyword(s):  
Mechanical Characteristics ◽  
Pullout Test ◽  
Woven Fabrics ◽  
Force Balance ◽  
Balance Analysis

scholarly journals Theoretical and Experimental Estimation of the Stored Energy of Plain Knitted Fabrics Using Yarn Pullout Test

2012 ◽  
Vol 7 (1) ◽  
pp. 155892501200700 ◽  
Author(s):  
Azita Asayesh ◽  
Elaheh Niazkhani ◽  
Ali Asghar Asgharian Jeddi
Keyword(s):  
Pullout Test ◽  
Polyester Fabric ◽  
Force Balance ◽  
Stored Energy ◽  
Knitted Fabrics ◽  
Pull Out ◽  
Plain Knitted Fabric ◽  
Stitch Length ◽  
Balance Analysis ◽  
Reasonable Prediction

The yarn pullout test is a suitable method for investigating the internal mechanical properties of the fabric structure which is established during the weaving or knitting process. In this study, a theoretical model is presented to estimate the stored energy of plain-knitted fabrics which is determined using yarn pullout. The model can predict the stored energy in the fabric, based on the fabric dimensional properties of stitch length and yarn contact angle using force balance analysis. Moreover, in order to evaluate the suggested model, three types of plain-knitted fabric from cotton, cotton/polyester and cotton/nylon with three different stitch lengths were produced and subjected to pull-out tests. Comparison between experimental and theoretical results, demonstrates a reasonable prediction. The results show that the cotton/polyester fabric has the maximum stored energy, because of its higher yarn to yarn friction coefficient. It was also found that, the increase in fabric's loop length leads to a decrease in the fabric's stored energy.

Cavitation Inception Behind a Jet-Propelled Body

2007 ◽  
Author(s):  
William Hambleton ◽  
Eduard Amromin ◽  
Roger E. A. Arndt ◽  
Svetlana Kovinskaya
Keyword(s):  
Velocity Ratio ◽  
The Body ◽  
Force Balance ◽  
Water Tunnel ◽  
Minimum Diameter ◽  
Cavitation Inception ◽  
Initial Comparison ◽  
Jet Velocity ◽  
Good Agreement

Cavitation inception behind an axissymmetric body driven by a waterjet has been studied experimentally and numerically. Water tunnel tests have been performed with the body mounted on a force balance. The transom of the body contained a nozzle located along the centerline. Tests were carried out for various water tunnel speeds such that jet velocity ratio, VJ/U, could be varied in the range 0 to 2. Distinctly different cavitation patterns were observed at zero jet velocity (when cavitation appeared in spiral vortices in such flows) and at a various jet velocity ratios (when cavitation appeared between counter-rotating vortices around the jet in such flows). Cavitation inception/disappearance has been determined visually. The body drag was also measured. An analytical method for determination of cavitation inception index has been developed on the basis of a viscous-inviscid interaction concept, with employment of special semiempirical approximations for vortices and consideration of surface tension. These approximations have been preliminarily validated for nozzle jet cavitation (for nozzle discharge in co-flow). It was assumed that visualization allows detection of cavities (bubbles) of 0.4mm-0.5mm diameter or larger. The cavitation inception index is defined as the cavitation index for cavities of such minimum diameter when these cavities are located between counter-rotating vortices. The initial comparison of predicted and measured values of the cavitation inception index shows good agreement.

Combined determination of the mechanical characteristics of polymer films

1968 ◽  
Vol 1 (5) ◽  
pp. 84-87
Author(s):  
O. F. Shlenskii ◽  
N. N. Khovanskaya ◽  
V. V. Lavrent'ev
Keyword(s):  
Polymer Films ◽  
Mechanical Characteristics

scholarly journals Effect of type cement on the mechanical strength of copper slag mortars

2013 ◽  
Vol 66 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Amin Nazer ◽  
Osvaldo Pavez ◽  
Ithamar Toledo
Keyword(s):  
Environmental Impact ◽  
Flexural Strength ◽  
Construction Industry ◽  
Mechanical Characteristics ◽  
Copper Slag ◽  
Cement Mortars ◽  
Alternative Material ◽  
Binder Type ◽  
Initial Resistance

Copper slag is a massive metallurgist waste. Annual production rises up to 24.6 million tons, approximately, and the main environmental impact derived from slag disposal is the usage of great soil extensions and the resulting visual contamination of the landscape. Along time, copper slag has been used in the manufacture of concrete and cement mortars. Thus, with the aim of verifying binder-type influence in the final hardness of mortars, two types of cement were used: regular cement and high initial resistance cement. Copper slag was characterized from the chemical, mineralogical and grading viewpoints. Official Chilean regulations were used in the applied methodology for the determination of some important slag parameters. Compression and flexural strength trials were carried out on cement mortars in specialized laboratories. The obtained results showed that mortars manufactured with copper slag presented a better resistance to compression and flexural strength than mortars manufactured with normal sand, and those made with high initial resistance cement were even better. It can be concluded from this work that copper slag offers optimal mechanical characteristics to be used in the manufacturing of cement mortars, becoming a sustainable and adequate alternative material for usage in the construction industry.

Sign in / Sign up

Export Citation Format

Share Document