Modeling of dielectric relaxation response of ceramic/polymer composite based on lead titanate

2006 ◽  
Vol 54 (1) ◽  
pp. 47-50 ◽  
Author(s):  
A. Peláiz-Barranco
Keyword(s):  
Dielectric Relaxation ◽  
Polymer Composite ◽  
Lead Titanate ◽  
Relaxation Response

Post-Fatigue Creep and Stress Relaxation Response of a Hybrid Polymer Composite

2017 ◽  
Author(s):  
Raghu V. Prakash ◽  
Monalisha Maharana
Keyword(s):  
Stress Relaxation ◽  
Polymer Composites ◽  
Polymer Composite ◽  
Fatigue Loading ◽  
Synthetic Fiber ◽  
Relaxation Response ◽  
Hybrid Polymer ◽  
Fatigue Cycling ◽  
Creep And Stress Relaxation ◽  
Hybrid Polymer Composite

Polymer composites have a characteristic, composition specific visco-elastic property which influences the damage progression during fatigue cycling. While some researchers have studied the time dependent constitutive response of polymer composites during the first cycle of fatigue loading, very few have experimentally investigated the dependence of visco-elastic response of built-up polymer composite materials at various stages of fatigue cycling [1]. Our earlier studies on fatigue response of polymer composites focused primarily on the stiffness degradation as a function of applied cycles of loading, which represents the gross response of the material [2]. While doing such an experiment, complimentary experimental techniques to measure the temperature evolution was attempted through the use of infrared thermal imaging technique, which gave some insight into the change in temperature response as a function of fatigue cycling. However, there was no systematic measurement of creep and stress relaxation response of the composite material as a function of induced fatigue damage. The present paper describes the results of creep and stress-relaxation obtained during uni-axial fatigue loading of a hybrid polymer composite material. For this purpose, a woven carbon fiber mat was chosen as the synthetic fiber and Flax fiber in the unidirectional form was chosen as the natural fiber that is laid between the two layers of woven carbon fiber mat. Epoxy LY 556 and hardener Araldite® was used for building up of composite laminate by hand-lay-up technique. Dog-bone shaped tensile specimens with a gage width of 13 mm and gage length of 57 mm were extracted from the 250 × 250 mm sq. plate laminate of 2.1 mm thickness using a numerical controlled milling machine. The specimens were tested at 35% of their median tensile strengths under fatigue at a positive stress ratio (Pmin/Pmax) of 0.1 in tension-tension loading. Prior to start of fatigue loading, the specimens were held in load control and the strain in the gage length was measured for understanding the creep response over 2500 seconds. For stress-relaxation characterization, the specimens were held in extensometer control over a period of 2500 sec. The creep and stress relaxation tests were carried out after periodic intervals of fatigue cycling. It was observed that in the case of un-impacted specimens, the creep rate is consistent with the stiffness variation, which in turn, is dependent on the number of fatigue cycles - till it showed signs of de-lamination. Thereafter it was governed by the woven synthetic fiber response. Similarly, the stress relaxation response was found to decrease with increasing fatigue cycles. In case of impacted specimens, the local deformation had a prominent role in terms of creep and stress relaxation response.

Effect of organo-clay on the dielectric relaxation response of silicone rubber

2009 ◽  
Vol 19 (2) ◽  
pp. 025002 ◽  
Author(s):  
N Gharavi ◽  
M Razzaghi-Kashani ◽  
N Golshan-Ebrahimi
Keyword(s):  
Dielectric Relaxation ◽  
Silicone Rubber ◽  
Relaxation Response ◽  
Organo Clay

Ultrafast dielectric relaxation response of polar liquids

1997 ◽  
Vol 106 (6) ◽  
pp. 2348-2354 ◽  
Author(s):  
L. F. del Castillo ◽  
L. A. Dávalos-Orozco ◽  
L. S. Garcı́a-Colı́n
Keyword(s):  
Dielectric Relaxation ◽  
Relaxation Response ◽  
Polar Liquids

Dielectric relaxation phenomena in lead titanate crystals

2012 ◽  
Vol 76 (1) ◽  
pp. 118-119
Author(s):  
V. G. Gavrilyachenko ◽  
A. F. Semenchev ◽  
E. M. Panchenko ◽  
E. I. Avakyan
Keyword(s):  
Dielectric Relaxation ◽  
Lead Titanate ◽  
Relaxation Phenomena

On the transients of the nonlinear dielectric relaxation response

1994 ◽  
Vol 62 (1-3) ◽  
pp. 83-92 ◽  
Author(s):  
Jean-Louis Déjardin ◽  
Georges Deblais ◽  
Belkacem Boulli ◽  
Olivier Henri-Rousseau
Keyword(s):  
Dielectric Relaxation ◽  
Relaxation Response ◽  
Nonlinear Dielectric
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