Stability of a noncircular cylinder in a matrix with small strains

1989 ◽  
Vol 25 (6) ◽  
pp. 553-557
Author(s):  
D. A. Musaev
2003 ◽  
Vol 778 ◽  
Author(s):  
Rajdip Bandyopadhyaya ◽  
Weizhi Rong ◽  
Yong J. Suh ◽  
Sheldon K. Friedlander

AbstractCarbon black in the form of nanoparticle chains is used as a reinforcing filler in elastomers. However, the dynamics of the filler particles under tension and their role in the improvement of the mechanical properties of rubber are not well understood. We have studied experimentally the dynamics of isolated nanoparticle chain aggregates (NCAs) of carbon made by laser ablation, and also that of carbon black embedded in a polymer film. In situ studies of stretching and contraction of such chains in the transmission electron microscope (TEM) were conducted under different maximum values of strain. Stretching causes initially folded NCA to reorganize into a straight, taut configuration. Further stretching leads to either plastic deformation and breakage (at 37.4% strain) or to a partial elastic behavior of the chain at small strains (e.g. 2.3% strain). For all cases the chains were very flexible under tension. Similar reorientation and stretching was observed for carbon black chains embedded in a polymer film. Such flexible and elastic nature of NCAs point towards a possible mechanism of reinforcement of rubber by carbon black fillers.


1999 ◽  
Author(s):  
Hansruedi Maurer ◽  
Jolanda Giudici‐Trausch ◽  
Michiel van der Veen ◽  
Sarah M. Springman

1963 ◽  
Vol 36 (2) ◽  
pp. 407-421 ◽  
Author(s):  
Glenn E. Warnaka

Abstract Many common elastomeric materials have two ranges of dynamic-mechanical behavior. Such materials behave as viscoelastomers at very small strains and as plastoelastomers at strains of practical engineering interest. The change from viscoelastic to plastoelastic behavior occurs at dynamic strain amplitudes of 0.001 inches per inch to 0.005 inches per inch. In the plastoelastic range, the dynamic elastic modulus decreases with increasing dynamic strain amplitude. Loss factor reaches a maximum in the plastoelastic range.


2018 ◽  
Vol 140 (2) ◽  
Author(s):  
R. C. Picu ◽  
S. Deogekar ◽  
M. R. Islam

Connective tissue mechanics is highly nonlinear, exhibits a strong Poisson's effect, and is associated with significant collagen fiber re-arrangement. Although the general features of the stress–strain behavior have been discussed extensively, the Poisson's effect received less attention. In general, the relationship between the microscopic fiber network mechanics and the macroscopic experimental observations remains poorly defined. The objective of the present work is to provide additional insight into this relationship. To this end, results from models of random collagen networks are compared with experimental data on reconstructed collagen gels, mouse skin dermis, and the human amnion. Attention is devoted to the mechanism leading to the large Poisson's effect observed in experiments. The results indicate that the incremental Poisson's contraction is directly related to preferential collagen orientation. The experimentally observed downturn of the incremental Poisson's ratio at larger strains is associated with the confining effect of fibers transverse to the loading direction and contributing little to load bearing. The rate of collagen orientation increases at small strains, reaches a maximum, and decreases at larger strains. The peak in this curve is associated with the transition of the network deformation from bending dominated, at small strains, to axially dominated, at larger strains. The effect of fiber tortuosity on network mechanics is also discussed, and a comparison of biaxial and uniaxial loading responses is performed.


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