Stress relaxation of wood during elevating and lowering processes of temperature and the set after relaxation II: consideration of the mechanism and simulation of stress relaxation behavior using a viscoelastic model

2002 ◽  
Vol 48 (2) ◽  
pp. 119-125 ◽  
Author(s):  
Ikuho Iida ◽  
Michiyasu Kudo ◽  
Jyunji Onizuka ◽  
Yutaka Ishimaru ◽  
Yuzo Furuta
Keyword(s):  
Stress Relaxation ◽  
Viscoelastic Model ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior

Modeling Stress-Relaxation Behavior of the Periodontal Ligament During the Initial Phase of Orthodontic Treatment

2013 ◽  
Vol 135 (9) ◽  
Author(s):  
Dan L. Romanyk ◽  
Garrett W. Melenka ◽  
Jason P. Carey
Keyword(s):  
Stress Relaxation ◽  
Periodontal Ligament ◽  
Orthodontic Treatment ◽  
Viscoelastic Model ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior ◽  
Cubic Form ◽  
Viscoelastic Models ◽  
Applied Forces

The periodontal ligament is the tissue that provides early tooth motion as a result of applied forces during orthodontic treatment: a force-displacement behavior characterized by an instantaneous displacement followed by a creep phase and a stress relaxation phase. Stress relaxation behavior is that which provides the long-term loading to and causes remodelling of the alveolar bone, which is responsible for the long-term permanent displacement of the tooth. In this study, the objective was to assess six viscoelastic models to predict stress relaxation behavior of rabbit periodontal ligament (PDL). Using rabbit stress relaxation data found in the literature, it was found that the modified superposition theory (MST) model best predicts the rabbit PDL behavior as compared to nonstrain-dependent and strain-dependent versions of the Burgers four-parameter and the five-parameter viscoelastic models, as well as predictions by Schapery's viscoelastic model. Furthermore, it is established that using a quadratic form for MST strain dependency provides more stable solutions than the cubic form seen in previous studies.

Effects of accelerator type on stress relaxation behavior and network structure of aged natural rubber/chloroprene rubber vulcanizates

2016 ◽  
Vol 49 (5) ◽  
pp. 381-396 ◽  
Author(s):  
Farzad A Nobari Azar ◽  
Murat Şen
Keyword(s):  
Stress Relaxation ◽  
Natural Rubber ◽  
Network Structure ◽  
Structural Changes ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior ◽  
Rubber Blends ◽  
Chloroprene Rubber ◽  
Weather Changes ◽  
Behavior Network

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.

scholarly journals Stress-relaxation behavior in gels with ionic and covalent crosslinks

2010 ◽  
Vol 107 (6) ◽  
pp. 063509 ◽  
Author(s):  
Xuanhe Zhao ◽  
Nathaniel Huebsch ◽  
David J. Mooney ◽  
Zhigang Suo
Keyword(s):  
Stress Relaxation ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior ◽  
Covalent Crosslinks

Reloading Stress Relaxation Behavior Analysis Based on a Creep Model for High Temperature Bolting Steel

2013 ◽  
Vol 328 ◽  
pp. 950-954
Author(s):  
Wei Wei Zhang ◽  
Hong Xu ◽  
Hong Yuan Li
Keyword(s):  
High Temperature ◽  
Stress Relaxation ◽  
Steady State Creep ◽  
Relaxation Behavior ◽  
Creep Model ◽  
National Research Institute ◽  
Time Intervals ◽  
Stress Relaxation Behavior ◽  
Proposed Model ◽  
Good Agreement

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.

Long-term stress relaxation behavior of Polyaniline-EPDM blends using the time-temperature-strain superposition method

2018 ◽  
Vol 6 (2) ◽  
pp. 025318 ◽  
Author(s):  
Muhammad Shafiq Irfan ◽  
Yasir Qayyum Gill ◽  
Motahira Hashmi ◽  
Sana Ullah ◽  
Farhan Saeed ◽  
...  
Keyword(s):  
Stress Relaxation ◽  
Relaxation Behavior ◽  
Superposition Method ◽  
Stress Relaxation Behavior ◽  
Temperature Strain

scholarly journals Effect of Sintering Temperature on Stress Relaxation Behavior of Sintered Nano-sized Ag Particles

2016 ◽  
Vol 5 (4) ◽  
pp. 259-265 ◽  
Author(s):  
Ryutaro SHIODA ◽  
Yoshiharu KARIYA ◽  
Noritsuka MIZUMURA ◽  
Koji SASAKI
Keyword(s):  
Stress Relaxation ◽  
Sintering Temperature ◽  
Relaxation Behavior ◽  
Stress Relaxation Behavior ◽  
Ag Particles
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