scholarly journals Measurement of the stress/strain response of energetic materials as a function of strain rate and temperature: PBX 9501 and Mock 9501

1996 ◽  
Author(s):  
David J. Funk ◽  
Gary W. Laabs ◽  
Paul D. Peterson ◽  
Blaine W. Asay
2015 ◽  
Vol 3 (2) ◽  
pp. 80-85
Author(s):  
Sunita Mishra ◽  
Tanusree Chakraborty ◽  
Dipanjan Basu

2013 ◽  
Vol 683 ◽  
pp. 314-317
Author(s):  
Hong Fu Xiang ◽  
Jing Hai Tao ◽  
Ji Heng Wang ◽  
Hui Li ◽  
An Lun Dai

A beta phase containing titanium aluminum compound was prepared. Isothermal Fatigue(IF) were subjected at 650 °C at three strain rates, such as 6.67×10-3s-1, 6.67×10-4s-1, 6.67×10-5s-1to determine the effect of strain rate on cyclic stress-strain response (CSSR) of TiAl alloy during IF tests. The curves of cyclic stress-strain response were discussed and dislocations configuration were also observed by TEM. The results show that strain rates have an apparent effect on CSSR of TiAl alloy during IF tests and CSSR was identified that it had a close relationship with dislocation configuration and deformation twin.


Author(s):  
Srihari Kurukuri ◽  
Michael J. Worswick ◽  
Dariush Ghaffari Tari ◽  
Raja K. Mishra ◽  
Jon T. Carter

The constitutive response of a commercial magnesium alloy rolled sheet (AZ31B-O) is studied based on room temperature tensile and compressive tests at strain rates ranging from 10 −3 to 10 3  s −1 . Because of its strong basal texture, this alloy exhibits a significant tension–compression asymmetry (strength differential) that is manifest further in terms of rather different strain rate sensitivity under tensile versus compressive loading. Under tensile loading, this alloy exhibits conventional positive strain rate sensitivity. Under compressive loading, the flow stress is initially rate insensitive until twinning is exhausted after which slip processes are activated, and conventional rate sensitivity is recovered. The material exhibits rather mild in-plane anisotropy in terms of strength, but strong transverse anisotropy ( r -value), and a high degree of variation in the measured r -values along the different sheet orientations which is indicative of a higher degree of anisotropy than that observed based solely upon the variation in stresses. This rather complex behaviour is attributed to the strong basal texture, and the different deformation mechanisms being activated as the orientation and sign of applied loading are varied. A new constitutive equation is proposed to model the measured compressive behaviour that captures the rate sensitivity of the sigmoidal stress–strain response. The measured tensile stress–strain response is fit to the Zerilli–Armstrong hcp material model.


2005 ◽  
Vol 495-497 ◽  
pp. 1001-1006 ◽  
Author(s):  
Carlos Tomé ◽  
George C. Kaschner

Hexagonal materials deform plastically by activating diverse slip and twinning modes. The activation of such modes depends on their relative critical stresses, function of temperature and strain rate, and the orientation of the crystals with respect to the loading direction. For a constitutive description of these materials to be reliable, it has to account for texture evolution associated with twin reorientation, and for the effect of the twin barriers on dislocation propagation and on the stress-strain response. In this work we introduce a model for twinning which accounts explicitly for the composite character of the grain, formed by a matrix with embedded twin lamellae which evolve with deformation. Texture evolution takes place through reorientation due to slip and twinning. The role of the twins as barriers to dislocations is explicitly incorporated into the hardening description via a directional Hall-Petch mechanism. We apply this model to the interpretation of compression experiments both, monotonic and changing the loading direction, done in rolled Zr at 76K.


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