The Bending and Recovery of Fabrics under Conditions of Changing Temperature and Relative Humidity

1976 ◽  
Vol 46 (2) ◽  
pp. 113-122 ◽  
Author(s):  
B. M. Chapman

The bending stress relaxation and recovery behavior of fabrics under conditions of changing temperature and humidity has been investigated. The fabric recovery is successfully predicted, from its stress relaxation behavior and a frictional parameter, using a previously presented model consisting of a generalized linear viscoelastic element in parallel with a frictional element. Furthermore, a viscoelastic parameter, simply obtainable from the relaxation data, together with the frictional parameter, have been shown to correlate well with observed recovery and may be useful as convenient indicators of fabric wrinkle performance.

Author(s):  
Pan Wang ◽  
Li-jun Wang ◽  
Dong Li ◽  
Zhi-gang Huang ◽  
Benu Adhikari ◽  
...  

Abstract: Stress-relaxation behavior of single rice kernel was studied using a dynamic mechanical analyzer (DMA) in compression mode. The relaxation modulus was measured in a moisture content range of 12–30 % on dry basis (d.b.) and a temperature range of 25–80°C. A constant stain value of 1 % (within the linear viscoelastic range) was selected during the stress-relaxation tests. The relaxation modulus was found to decrease as the temperature and moisture increased. A master curve of relaxation modulus as a function of temperature and moisture content was generated using the time–moisture–temperature superposition principle. Results showed that the generalized Maxwell model satisfactorily fitted the experimental data of the stress-relaxation behavior and the master curve of relaxation modulus (R2> 0.997). By shifting the temperature curves horizontally, the activation energy of the stress relaxation was obtained which significantly decreased with increase in the moisture content.


2016 ◽  
Vol 49 (5) ◽  
pp. 381-396 ◽  
Author(s):  
Farzad A Nobari Azar ◽  
Murat Şen

Natural rubber/chloroprene rubber (NR/CR) blends are among the commonly used rubber blends in industry and continuously are exposed to severe weather changes. To investigate the effects of accelerator type on the network structure and stress relaxation of unaged and aged NR/CE vulcanizates, tetramethyl thiuram disulfide, 2-mercaptobenzothiazole, and diphenyl guanidine accelerators have been chosen to represent fast, moderate, and slow accelerator groups, respectively. Three batches have been prepared with exactly the same components and mixing conditions differing only in accelerator type. Temperatures scanning stress relaxation and pulse nuclear magnetic resonance techniques have been used to reveal the structural changes of differently accelerated rubber blends before and after weathering. Nonoxidative thermal decomposition analyses have been carried out using a thermogravimetric analyzer. Results indicate that there is a strong interdependence between accelerator type and stress relaxation behavior, network structure, cross-linking density, and aging behavior of the blends. Accelerator type also affects decomposition energy of the blends.


2010 ◽  
Vol 107 (6) ◽  
pp. 063509 ◽  
Author(s):  
Xuanhe Zhao ◽  
Nathaniel Huebsch ◽  
David J. Mooney ◽  
Zhigang Suo

2013 ◽  
Vol 328 ◽  
pp. 950-954
Author(s):  
Wei Wei Zhang ◽  
Hong Xu ◽  
Hong Yuan Li

An analytical method based on a creep model is being developed to investigate the effect of retightening on stress relaxation behavior for high-temperature turbine and valve studs/bolts. In order to validate the approach, the calculated results are compared to the results of uniaxial reloading stress relaxation testing, which were performed by the National Research Institute for Metals of Japan (NRIM) for 12Cr-1Mo-1W-1/4V stainless steel bolting material at 550°C. It was shown that the proposed model based on Altenbach-Gorash-Naumenko creep model for the primary and steady state creep could be applied for the present data. The calculated residual stresses versus time curves were in good agreement with the measured for initial stress level of 273.6MPa at 550°C and for specific reloading time intervals of 24, 72, 240, and 720 hours.


2018 ◽  
Vol 6 (2) ◽  
pp. 025318 ◽  
Author(s):  
Muhammad Shafiq Irfan ◽  
Yasir Qayyum Gill ◽  
Motahira Hashmi ◽  
Sana Ullah ◽  
Farhan Saeed ◽  
...  

2016 ◽  
Vol 5 (4) ◽  
pp. 259-265 ◽  
Author(s):  
Ryutaro SHIODA ◽  
Yoshiharu KARIYA ◽  
Noritsuka MIZUMURA ◽  
Koji SASAKI

Sign in / Sign up

Export Citation Format

Share Document