Wave Propagation in the Split Hopkinson Pressure Bar

1983 ◽  
Vol 105 (1) ◽  
pp. 61-66 ◽  
Author(s):  
P. S. Follansbee ◽  
C. Frantz
Keyword(s):  
Wave Propagation ◽  
Elastic Wave ◽  
Split Hopkinson Pressure Bar ◽  
Strain Curve ◽  
Leading Edge ◽  
Elastic Wave Propagation ◽  
Mathematical Treatment ◽  
Hopkinson Pressure Bar ◽  
Split Hopkinson ◽  
Pressure Bar

Elastic wave propagation in the split Hopkinson pressure bar (SHPB) is discussed with an emphasis on the origin and nature of the oscillations that often trail the leading edge of the pressure wave. We show that in the conditions of the SHPB test the pressure bars vibrate in the fundamental mode and that elastic wave propagation can be fully described mathematically. Excellent agreement is found between experimental results and predictions of the mathematical treatment. This suggests that dispersion effects in the pressure bars can be removed from the strain gage records, which reduces the magnitude of the oscillations in the resulting stress strain curve.

scholarly journals Influence of Imperfect Position of a Striker and Input Bar on Wave Propagation in a Split Hopkinson Pressure Bar (SHPB) Setup with a Pulse-Shape Technique

2020 ◽  
Vol 10 (7) ◽  
pp. 2423 ◽  
Author(s):  
Robert Panowicz ◽  
Marcin Konarzewski
Keyword(s):  
Wave Propagation ◽  
Inclination Angle ◽  
High Frequency ◽  
Pulse Shape ◽  
Split Hopkinson Pressure Bar ◽  
Hopkinson Pressure Bar ◽  
Pulse Shaper ◽  
Split Hopkinson ◽  
Pressure Bar

The effect of using a pulse shaper technique, such as rounding a striker or applying a pulse shaper on the signals recorded with the split Hopkinson pressure bar (SHPB) technique, when the striker and the input bar are in an imperfect position, was investigated. Two of the most common cases have been analyzed: an offset of the symmetry axes of the striker and the input bar; and an inclination angle between the striker and the input bar. LS-Dyna software was used to examine this problem numerically. The inclination angle imperfection has a significant impact on signal disturbances, whereas the use of a rounded striker significantly affects the limitation of the vibration flexural modes. In all considered cases, a slight imperfection causes a reduction in the high-frequency Pochhammer–Chree oscillations.

Dispersion Investigation in the Split Hopkinson Pressure Bar

1990 ◽  
Vol 112 (3) ◽  
pp. 309-314 ◽  
Author(s):  
J. C. Gong ◽  
L. E. Malvern ◽  
D. A. Jenkins
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Strain Curve ◽  
Concrete Specimen ◽  
Fourier Series Expansion ◽  
Hopkinson Pressure Bar ◽  
Correction Technique ◽  
Split Hopkinson ◽  
Mode Vibration ◽  
Pressure Bar ◽  
Good Agreement

Dispersion of an elastic wave propagating in a 76.2-mm-diameter (3 in.) Split Hopkinson Pressure Bar system was investigated with two consecutive pulses recorded in the transmitter bar. Assuming that the dispersive high frequency oscillatory components riding on the top of the main pulse originate from the first mode vibration, the dispersion was corrected by using the Fast Fourier Transform (FFT) and Fourier series expansion numerical schemes. The good agreement validates the assumption that only the first mode was significant. The dispersion correction technique was employed in a test of a concrete specimen having the same diameter as that of the SHPB. Better agreement of the two specimen-bar interface stresses versus time and fewer oscillations in the stress-strain curve demonstrated advantages of the application of dispersion corrections.

Numerical Simulation of Double Specimens in Split Hopkinson Pressure Bar Testing

2010 ◽  
Vol 654-656 ◽  
pp. 2483-2486
Author(s):  
Muhammad Agus Kariem ◽  
John H. Beynon ◽  
Dong Ruan
Keyword(s):  
Dynamic Behaviour ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Performance ◽  
Strain Curve ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Element Analysis ◽  
Specimen Test ◽  
Split Hopkinson ◽  
Pressure Bar

The split Hopkinson pressure bar (SHPB) is the most commonly used technique to characterize the dynamic behaviour of materials at very high strain rates. However, a classic single specimen test only generates a single stress-strain curve at the average strain rate of the test. This paper proposes three arrangements on the use of double specimens in SHPB compression testing. All waves propagating along the bars have been used to analyse the dynamic behaviour of the specimens. To simulate the test and predict its dynamic performance, an axisymmetric finite element analysis using LS-DYNA was conducted for the experiment using 13 mm bar diameter. The validity of the simulations was checked with experimental data from normal SHPB testing. Based on the simulations, the modified techniques are achievable and at least two stress-strain curves of materials can be extracted without violating the requirement of a valid SHPB test.

scholarly journals Dynamic High Strain Rate Characterization of Lithium-Ion Nickel–Cobalt–Aluminum (NCA) Battery Using Split Hopkinson Tensile/Pressure Bar Methodology

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5061
Author(s):  
Hafiz Fadillah ◽  
Sigit Puji Santosa ◽  
Leonardo Gunawan ◽  
Akbar Afdhal ◽  
Agus Purwanto
Keyword(s):  
Dynamic Behavior ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Strain Curve ◽  
Lithium Ion ◽  
Thin Foil ◽  
Hopkinson Pressure Bar ◽  
Split Hopkinson ◽  
Pressure Bar

The dynamic behavior of the lithium-ion battery is evaluated by simulating the full battery system and each corresponding component, including the jellyroll and thin-foil electrodes. The thin-foil electrodes were evaluated using a novel design of split Hopkinson tensile bar (SHTB), while the jellyroll was evaluated using the split Hopkinson pressure bar (SHPB). A new stacking method was employed to strengthen the stress wave signal of the thin-foil electrodes in the SHTB simulation. The characteristic of the stress–strain curve should remain the same regardless of the amount of stacking. The jellyroll dynamic properties were characterized by using the SHPB method. The jellyroll was modeled with Fu-Chang foam and modified crushable foam and compared with experimental results at the loading speeds of 20 and 30 m/s. The dynamic behavior compared very well when it was modeled with Fu-Chang foam. These studies show that the dynamic characterization of Li-ion battery components can be evaluated using tensile loading of stacked layers of thin foil aluminum and copper with SHTB methodology as well as the compressive loading of jellyroll using SHPB methodology. Finally, the dynamic performance of the full system battery can be simulated by using the dynamic properties of each component, which were evaluated using the SHTB and SHPB methodologies.

The mechanical properties of copper zinc and aluminium tested in compression

1972 ◽  
Vol 327 (1568) ◽  
pp. 23-46 ◽  
Keyword(s):  
Mechanical Behaviour ◽  
Split Hopkinson Pressure Bar ◽  
Compressive Loading ◽  
Strain Curve ◽  
Hopkinson Pressure Bar ◽  
Gas Gun ◽  
Split Hopkinson ◽  
Copper Zinc ◽  
Pressure Bar ◽  
Wave Induced

The mechanical behaviour of some metals has been investigated experimentally for compressive loading cycles of approximately 100 and 370 μs duration and for steady-state compressive loading. For the dynamic measurements the split Hopkinson pressure bar technique has been used in which cylindrical specimens are sandwiched between two rods and deformed under the action of a compressive stress wave induced by impacting the free end of one of the rods with a projectile launched by a light gas gun. The experimental results show that for the available range of strain rates the stress-strain curve is independent of strain rate. These results are compared with the mechanical behaviour predicted by a particular form of nonlinear mechanical equation of state.

A Numerical Verification of the Reliability of a Split Hopkinson Pressure Bar with a Total Bar Length of 3 m and a Diameter of 1 Inch

2015 ◽  
Vol 799-800 ◽  
pp. 681-684 ◽  
Author(s):  
Hyun Ho Shin ◽  
Ho Yun Lee ◽  
Jong Bong Kim ◽  
Yo Han Yoo
Keyword(s):  
Numerical Experiment ◽  
Numerical Experiments ◽  
Split Hopkinson Pressure Bar ◽  
Strain Curve ◽  
Hopkinson Bar ◽  
Numerical Verification ◽  
Hopkinson Pressure Bar ◽  
Stress Strain Curve ◽  
Split Hopkinson ◽  
Pressure Bar

A short split Hopkinson bar system with a total bar length of 3 m (a 2 m input bar plus a 1 m output bar), a striker length of 254 mm, and a diameter of 25.4 mm, is designed. Through numerical experiments, the stress vs. strain curve and the rate vs. strain curve of the specimen are obtained from the bar signals. These measured curves are reasonably consistent with the input stress-strain curve of the specimen for the numerical experiment and the prediction by the recently reported rate equation, respectively, verifying the reliability of the designed SHPB system.

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