scholarly journals Experiments and simulation of split Hopkinson Bar tests on sand

2014 ◽  
Vol 500 (11) ◽  
pp. 112018 ◽  
Author(s):  
P D Church ◽  
P J Gould ◽  
A D Wood ◽  
A Tyas
Strain ◽  
2021 ◽  
Author(s):  
Anatoly M. Bragov ◽  
Leonid A. Igumnov ◽  
Aleksandr Y. Konstantinov ◽  
Leopold Kruszka ◽  
Dmitry A. Lamzin ◽  
...  

2018 ◽  
Vol 183 ◽  
pp. 02006 ◽  
Author(s):  
Amos Gilat ◽  
Jeremy D. Seidt

The Split Hopkinson Bar (SHB) technique is used for high strain rate testing of T800/F3900 composite in compression, tension and shear. Digital Image Correlation (DIC) is used for measuring the full-field deformation on the surface of the specimen by using Shimadzu HPV-X2 high-speed video camera. Compression tests have been done on specimens machined from a unidirectional laminate in the 0°and 90° directions. Tensile tests were done in the 90° direction. Shear tests were done by using a notched specimen in a compression SHB apparatus. To study the effect of strain rate, quasi-static testing was also done using DIC and specimens with the same geometry as in the SHB tests. The results show that the DIC technique provides accurate strain measurements even at strains that are smaller than 1%. No strain rate effect is observed in compression in the 0° direction and significant strain rate effects are observed in compression and tension in the 90° direction, and in shear.


2015 ◽  
Vol 620 ◽  
pp. 241-245 ◽  
Author(s):  
Sun Da-xiang ◽  
Zhang Xin-ming ◽  
Ye Ling-ying ◽  
Gu Gang ◽  
Jiang Hai-chun ◽  
...  

Author(s):  
Hyunho Shin ◽  
Jong-Bong Kim

The specimen strain rate in the split Hopkinson bar (SHB) test has been formulated based on a one-dimensional assumption. The strain rate is found to be controlled by the stress and strain of the deforming specimen, geometry (the length and diameter) of specimen, impedance of bar, and impact velocity. The specimen strain rate evolves as a result of the competition between the rate-increasing and rate-decreasing factors. Unless the two factors are balanced, the specimen strain rate generally varies (decreases or increases) with strain (specimen deformation), which is the physical origin of the varying nature of the specimen strain rate in the SHB test. According to the formulated strain rate equation, the curves of stress–strain and strain rate–strain are mutually correlated. Based on the correlation of these curves, the strain rate equation is verified through a numerical simulation and experiment. The formulated equation can be used as a tool for verifying the measured strain rate–strain curve simultaneously with the measured stress–strain curve. A practical method for predicting the specimen strain rate before carrying out the SHB test has also been presented. The method simultaneously solves the formulated strain rate equation and a reasonably estimated constitutive equation of specimen to generate the anticipated curves of strain rate–strain and stress–strain in the SHB test. An Excel® program to solve the two equations is provided. The strain rate equation also indicates that the increase in specimen stress during deformation (e.g., work hardening) plays a role in decreasing the slope of the strain rate–strain curve in the plastic regime. However, according to the strain rate equation, the slope of the strain rate–strain curve in the plastic deformation regime can be tailored by controlling the specimen diameter. Two practical methods for determining the specimen diameter to achieve a nearly constant strain rate are presented.


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