Specimen size and shape effect in split Hopkinson pressure bar testing

The specimen size has always been crucial in defining the materials behaviour and becomes more important when materials are subjected to high rates of loadings. In the current study, the effect of specimen size on the mechanical behaviour of AZ31B alloy has been investigated under dynamic compression using the Split Hopkinson Pressure Bar (SHPB) and results are presented. Specimens were made in different sizes with fixed slenderness ratio (l/d) of 0.5 and with bar to specimen diameter ratio varying between 0.47 and 0.79. When deformed at the same strain rate 1500±50s-1, the smaller specimens give higher stresses and smaller strains. The smaller size specimens give more uniform strain rate as compared to the larger size specimens. However, some spurious oscillations are observed in the stress-strain curves for smaller size specimens. The alloy shows higher hardening behavior for larger size specimen; the hardening exponent n is larger for larger size specimens.

Download Full-text

Specimen Size Effect and Dynamic Increase Factor for Basalt Fiber–Reinforced Concrete Using Split Hopkinson Pressure Bar

Journal of Materials in Civil Engineering ◽

10.1061/(asce)mt.1943-5533.0003992 ◽

2021 ◽

Vol 33 (12) ◽

Author(s):

Kavita Ganorkar ◽

M. D. Goel ◽

Tanusree Chakraborty

Keyword(s):

Reinforced Concrete ◽

Size Effect ◽

Split Hopkinson Pressure Bar ◽

Basalt Fiber ◽

Specimen Size ◽

Fiber Reinforced Concrete ◽

Hopkinson Pressure Bar ◽

Dynamic Increase Factor ◽

Split Hopkinson ◽

Pressure Bar

Download Full-text

Analysis of the Impact of the Frequency Range of the Tensometer Bridge and Projectile Geometry on the Results of Measurements by the Split Hopkinson Pressure Bar Method

Metrology and Measurement Systems ◽

10.2478/mms-2013-0047 ◽

2013 ◽

Vol 20 (4) ◽

pp. 555-564 ◽

Cited By ~ 12

Author(s):

Wojciech Moćko

Keyword(s):

Test Bench ◽

Split Hopkinson Pressure Bar ◽

Dynamic Deformation ◽

Spectral Width ◽

Hopkinson Pressure Bar ◽

Computing Environment ◽

Split Hopkinson ◽

Pressure Bar ◽

The Impact ◽

Bench Model

Abstract The paper presents the results of the analysis of the striker shape impact on the shape of the mechanical elastic wave generated in the Hopkinson bar. The influence of the tensometer amplifier bandwidth on the stress-strain characteristics obtained in this method was analyzed too. For the purposes of analyzing under the computing environment ABAQUS / Explicit the test bench model was created, and then the analysis of the process of dynamic deformation of the specimen with specific mechanical parameters was carried out. Based on those tests, it was found that the geometry of the end of the striker has an effect on the form of the loading wave and the spectral width of the signal of that wave. Reduction of the striker end diameter reduces unwanted oscillations, however, adversely affects the time of strain rate stabilization. It was determined for the assumed test bench configuration that a tensometric measurement system with a bandwidth equal to 50 kHz is sufficient

Download Full-text