Fracture of Laminated and In Situ Niobium Silicide-Niobium Composites

1996 ◽  
Vol 434 ◽  
Author(s):  
J. D. Rigney
Keyword(s):  
Low Temperatures ◽  
Fracture Resistance ◽  
Fracture Behavior ◽  
High Strain ◽  
Theoretical Models ◽  
High Yield ◽  
Strain Rates ◽  
High Strain Rates ◽  
Ductile Phase

AbstractThe mechanisms contributing to the fracture resistance of refractory metal intermetallic composites containing a BCC metallic phase (niobium) were investigated using model Nb-Si laminates and in situ composites. The controlling influence of ductile phase yield strength and fracture behavior were investigated by varying laminate processing parameters, and/or altering temperatures and applied strain rates during fracture experiments on all materials. The fracture behavior of “ductile” constituents were found to be influenced by phase grain size, solid solution content, constraint (as influenced by interfacial bond strengths), and the testing condition (high strain rates and low temperatures). The measured fracture resistance, when compared to theoretical models, was shown to be controlled by the “toughness” of the “ductile” phase and independent of the fracture behavior promoted (cleavage and ductile). The loss in ductility due to cleavage by high constraint, high strain rates and/or low temperatures was compensated by high yield and cleavage fracture stresses in order to provide a level of toughening similar to that contributed by ligaments which failed with lower yield stresses and greater strains.

Deformation behavior of Al/Cu in-situ metal-intermetallic laminates at low and high strain rates

2021 ◽  
pp. 159767
Author(s):  
Kartheek. S.M. Sonti ◽  
Biswaranjan Dash ◽  
K.V. Vamsi ◽  
H. Bandyopadhyay ◽  
B. Ravisankar ◽  
...  
Keyword(s):  
Deformation Behavior ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates

Stress Softening in Carbon Black Reinforced Vulcanizates. Strain Rate and Temperature Effects

1966 ◽  
Vol 39 (5) ◽  
pp. 1530-1543 ◽  
Author(s):  
G. Kraus ◽  
C. W. Childers ◽  
K. W. Rollmann
Keyword(s):  
Carbon Black ◽  
Strain Rate ◽  
Low Temperatures ◽  
High Strain ◽  
Failure Behavior ◽  
Strain Rates ◽  
High Strain Rates ◽  
Temperature Function ◽  
Network Chain ◽  
Stress Softening

Abstract Stress softening of carbon black reinforced butadiene styrene rubber was studied as a function of the rate and temperature of the original tensile deformation. To a good approximation, stress softening depends on the product of the extension rate and a temperature function which is analytically well represented by the familiar Williams-Landel-Ferry relationship. When the elongation of the original deformation is also varied, a good correlation is obtained between stress softening and the maximum stress attained in the original extension, irrespective of the particular combination of strain, strain rate, and temperature used to achieve this stress. Variables which tend to increase the stiffness of the vulcanizate, such as increased degree of crosslinking or carbon black chain structure, also increase stress softening; dilution by plasticizers decreases it. Prestressing at high strain rates and low temperatures affects the stress—strain curve of the softened vulcanizates beyond the elongation of the original extension. Connections are established between stress softening and viscoelastic and failure behavior. The evidence presented favors the contribution of several mechanisms to the general phenomenon of stress softening. These are thixotropy of transient filler structures, network chain rupture, and breakage of “permanent” filler structure. The latter appears to be most important at high strain rates, low temperatures, and with highly reticulated “structure” blacks.

A comparison of the abilities of natural rubber (NR) and synthetic polyisoprene cis-1,4 rubber (IR) to crystallize under strain at high strain rates

2016 ◽  
Vol 18 (5) ◽  
pp. 3472-3481 ◽  
Author(s):  
Nicolas Candau ◽  
Laurent Chazeau ◽  
Jean-Marc Chenal ◽  
Catherine Gauthier ◽  
Etienne Munch
Keyword(s):  
Comparative Study ◽  
Natural Rubber ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Synthetic Rubber ◽  
Strain Induced Crystallization ◽  
First Time ◽  
Induced Crystallization

In situ WAXS experiments combined with a thermodynamic approach allowed for the first time a comparative study of strain induced crystallization of natural and synthetic rubber at high strain rates.

scholarly journals Compressive mechanical properties of HTPB propellant at low temperatures and high strain rates

2017 ◽  
Vol 7 ◽  
pp. 4079-4084 ◽  
Author(s):  
Xiangdong Chen ◽  
Jianwei Lai ◽  
Xin-long Chang ◽  
Youhong Zhang ◽  
Lei Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperatures ◽  
High Strain ◽  
Strain Rates ◽  
High Strain Rates ◽  
Htpb Propellant
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