Investigation of the Payne Effect and its Temperature Dependence on Silica-Filled Polydimethylsiloxane Networks. Part I: Experimental Results

2005 ◽  
Vol 78 (2) ◽  
pp. 211-231 ◽  
Author(s):  
F. Clément ◽  
L. Bokobza ◽  
L. Monnerie
Keyword(s):  
Elastic Modulus ◽  
Surface Treatment ◽  
Temperature Dependence ◽  
Shear Strain ◽  
Variable Temperature ◽  
Silica Particles ◽  
Experimental Results ◽  
Payne Effect ◽  
Low Shear

Abstract The Payne effect is studied in silica-filled polydimethylsiloxane networks, containing various silica loadings and at variable temperature. The effect of a permanent surface treatment of the silica particles, as well as the influence of the incorporation in the system of a processing aid agent, have been investigated. The amplitude of the Payne effect is reduced by introducing a permanent treatment of the silica or a processing aid. Contrary to the unfilled network which shows the typical entropic dependence of the elastic modulus, the low shear strain elastic modulus of filled networks decreases when temperature increases. When the shear strain increases, this temperature dependence becomes less and less pronounced, and reaches a plateau value at deformations above 100%.

Investigation of the Payne Effect and its Temperature Dependence on Silica-Filled Polydimethylsiloxane Networks. Part II: Test of Quantitative Models

2005 ◽  
Vol 78 (2) ◽  
pp. 232-244 ◽  
Author(s):  
F. Clément ◽  
L. Bokobza ◽  
L. Monnerie
Keyword(s):  
Temperature Dependence ◽  
Volume Fraction ◽  
Variable Temperature ◽  
Experimental Results ◽  
Influence Of Temperature ◽  
Payne Effect ◽  
Quantitative Models ◽  
Filler Volume Fraction ◽  
Influence Of Temperature On

Abstract The results obtained in Part I, on Polydimethylsiloxane (PDMS) networks filled with treated Aerosil A300 silica at variable temperature and various loadings, have been used to test the quantitative models of the Payne effect proposed by Kraus, Huber-Vilgis, and Maier-Göritz. Each model is able to account only for a part of the experimental results: Kraus and Maier-Vilgis for the variation of the Payne effect with filler volume fraction, Maier-Göritz for the influence of temperature on the Payne effect. But neither of these quantitative models is able to fit the whole set of experimental results on G′ and G″ with a unique set of parameters.

On the nominal transverse shear strain to characterize the severity of creasing

TAPPI Journal ◽  
2018 ◽  
Vol 17 (04) ◽  
pp. 231-240
Author(s):  
Douglas Coffin ◽  
Joel Panek
Keyword(s):  
Shear Strain ◽  
Transverse Shear ◽  
Elastic Limit ◽  
Experimental Results ◽  
Transverse Shear Strain ◽  
Maximum Strain ◽  
Machine Direction ◽  
Engineering Approach ◽  
Wide Range ◽  
Analytic Expression

A transverse shear strain was utilized to characterize the severity of creasing for a wide range of tooling configurations. An analytic expression of transverse shear strain, which accounts for tooling geometry, correlated well with relative crease strength and springback as determined from 90° fold tests. The experimental results show a minimum strain (elastic limit) that needs to be exceeded for the relative crease strength to be reduced. The theory predicts a maximum achievable transverse shear strain, which is further limited if the tooling clearance is negative. The elastic limit and maximum strain thus describe the range of interest for effective creasing. In this range, cross direction (CD)-creased samples were more sensitive to creasing than machine direction (MD)-creased samples, but the differences were reduced as the shear strain approached the maximum. The presented development provides the foundation for a quantitative engineering approach to creasing and folding operations.

scholarly journals Early-Age Tensile Bond Characteristics of Epoxy Coatings for Underwater Applications

Coatings ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 757 ◽  
Author(s):  
Kim ◽  
Hong ◽  
Han ◽  
Kim
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Epoxy Resin ◽  
Coating Thickness ◽  
Experimental Results ◽  
Early Age ◽  
Curing Time ◽  
Bond Performance ◽  
Coating Type ◽  
Bond Characteristics

In this study, coating equipment for the effective underwater repair of submerged structures was developed. The tensile bond characteristics of selected epoxy resin coatings were investigated by coating the surface of a specimen using each of the four types of equipment. Using the experimental results, the tensile bond strength and the coating thickness were analyzed according to the type of equipment, coating, and curing time. The results show that the type of coating equipment used had the greatest effect on the measured bond strength and coating thickness of the selected coatings. However, the effect of coating type and curing time on the bond strength and the thickness was observed to be insignificant. Compared with the developed equipment, the surface treatment of the coating was observed to be more effective when using the pre-existing equipment, and thus the bond performance of the coating was improved compared to using the pre-existing equipment. Based on the experimental results, improvements and needs involving the equipment for further research were discussed.

Experimental Study of the Plastic Interaction of Model Surface Asperities during Sliding

1968 ◽  
Vol 10 (2) ◽  
pp. 121-132 ◽  
Author(s):  
C. M. Edwards ◽  
J. Halling
Keyword(s):  
Experimental Study ◽  
Friction And Wear ◽  
Normal Force ◽  
Tangential Force ◽  
Experimental Results ◽  
Interfacial Conditions ◽  
High Adhesion ◽  
Theoretical Predictions ◽  
Very High ◽  
Low Shear

The paper describes an experimental study of the plastic interaction of triangular shaped lead model asperities deformed under conditions of plane strain. The investigation yields values of the normal and tangential force variations throughout the junction interaction and details of the plastic deformation particularly in relation to junction growth. A number of asperity interfacial conditions are considered ranging from complete adhesion to very low shear strengths achieved using p.t.f.e. strip. The experimental results are compared with an earlier theoretical solution to this problem and show reasonable agreement with the theoretical predictions. In particular it is shown that the normal force, which is usually compressive, may become tensile for conditions of high adhesion between the asperities. This leads to very high values of the macroscopic friction coefficient such as occur in hard vacuum situations. The experimental results for the various surface conditions show sufficient agreement with theoretical predictions to justify the use of this type of theoretical approach for the wider study of the friction and wear of mating surfaces.

scholarly journals Significantly increased low shear rate viscosity, blood elastic modulus, and RBC aggregation in adults following cardiac surgery

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Yi-Fan Wu ◽  
Po-Shun Hsu ◽  
Chien-Sung Tsai ◽  
Pin-Cheng Pan ◽  
Yeng-Long Chen
Keyword(s):  
Cardiac Surgery ◽  
Elastic Modulus ◽  
Shear Rate ◽  
Rbc Aggregation ◽  
Low Shear
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