Torsional split Hopkinson bar tests at strain rates above 104s−1

The design of sample geometries and the measurement of small strains are considered the main challenges when testing composite materials at high strain rates using the split Hopkinson bar technique. The aim of this paper is to assess two types of tensile sample geometries, namely dog-bone and straight strip, in order to study the tensile behaviour of basalt fibre reinforced composites at high strain rates using the split Hopkinson bar technique. 2D Digital image correlation technique was used to study the distribution of the strain fields within the gauge section at quasi-static and dynamic strain rates. Results showed that for the current experiments and the proposed clamping techniques, both sample geometries fulfilled the requirements of a valid split Hopkinson test, and achieved uniform strain fields within the gauge section. However, classical Hopkinson analysis tends to overestimate the actual strains in the gauge section for both geometries. It is, therefore, important to use a local deformation measurement when using these 2 geometries with the proposed clamping technique.

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On the Use of a Torsional Split Hopkinson Bar to Study Rate Effects in 1100-0 Aluminum

Journal of Applied Mechanics ◽

10.1115/1.3408771 ◽

1971 ◽

Vol 38 (1) ◽

pp. 83-91 ◽

Cited By ~ 172

Author(s):

J. Duffy ◽

J. D. Campbell ◽

R. H. Hawley

Keyword(s):

Test Procedure ◽

Hopkinson Bar ◽

Strain Rates ◽

Nominal Strain Rate ◽

Split Hopkinson Bar ◽

Amplitude Fluctuations ◽

Rate Effects ◽

Split Hopkinson ◽

Mechanical Pulse ◽

Compressive Tests

The difficulties involved in the accurate measurement of the flow stress of materials at high rates of deformation are reviewed, and methods of overcoming these difficulties are discussed. It is concluded that the best experimental method is that in which a split Hopkinson bar is adapted for torsion testing, and the loading pulse is approximately square in shape and has a relatively short duration. A description is given of apparatus which was developed to achieve this type of loading, the input wave being generated explosively. This wave was found to contain large amplitude fluctuations, and to eliminate these a mechanical “pulse smoother” was used. The operation of this device is described, and the test procedure, method of calibration, and possible sources of inaccuracy are discussed. Results are presented for 1100-0 aluminum alloy deformed at strain rates of the order of 800 sec−1 and are compared with those obtained at a nominal strain rate of 10−4 sec−1; the results are also compared with those obtained in compressive tests by other workers.

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Modeling torsional split Hopkinson bar tests at strain rates above 10,000 s−1

International Journal of Plasticity ◽

10.1016/s0749-6419(01)00055-9 ◽

2002 ◽

Vol 18 (5-6) ◽

pp. 787-799 ◽

Cited By ~ 31

Author(s):

Amos Gilat ◽

Ching-Shan Cheng

Keyword(s):

Hopkinson Bar ◽

Strain Rates ◽

Split Hopkinson Bar ◽

Split Hopkinson

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Dynamic tension of aluminum alloy AMg-6 in a facility of Split Hopkinson Bar

EPJ Web of Conferences ◽

10.1051/epjconf/201818302036 ◽

2018 ◽

Vol 183 ◽

pp. 02036

Author(s):

Victor Pushkov ◽

Alexey Yurlov ◽

Valery Leonov ◽

Andrew Tsibikov ◽

Tatiana Naydanova

Keyword(s):

Aluminum Alloy ◽

Hopkinson Bar ◽

Structural Materials ◽

Strain Rates ◽

Dynamic Tension ◽

Split Hopkinson Bar ◽

Split Hopkinson

The results are presented to create a facility for studying dynamic tension of structural materials by using the Split Hopkinson Bar Method (SHB method). The explosive method of loading and a cylindrical corner-rounding sample are used in a facility. A sample has threads at both end faces and it fastened in rods by the help of threads. The results of test experiments are presented in the facility for studying dynamic tension of the aluminum alloy AMg-6 at strain rates of 1160-1450 s-1. The diagrams of dynamic tension σ-ε were built. The data on peculiarities of deformation AMg-6 were gained.

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The Deformation of Lead in Torsion at High Strain Rates

Journal of Applied Mechanics ◽

10.1115/1.3422765 ◽

1972 ◽

Vol 39 (3) ◽

pp. 651-656 ◽

Cited By ~ 8

Author(s):

J. Duffy ◽

R. H. Hawley ◽

R. A. Frantz

Keyword(s):

Flow Stress ◽

High Strain ◽

Hopkinson Bar ◽

Explosive Loading ◽

Strain Rates ◽

High Strain Rates ◽

Split Hopkinson Bar ◽

Nominal Strain ◽

Split Hopkinson ◽

Loading Tests

Experiments are described in which specimens of lead are strained in torsion at high rates using the split Hopkinson bar and explosive loading. Tests were conducted at nominal strain rates of 1000 sec−1 and 5000 sec−1 as well as at “static” rates. Values of the flow stress correspond closely with those obtained in axial tests by other investigators at corresponding rates.

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A Review of the Torsional Split Hopkinson Bar

Advances in Civil Engineering ◽

10.1155/2018/2719741 ◽

2018 ◽

Vol 2018 ◽

pp. 1-17 ◽

Cited By ~ 3

Author(s):

Xiao Yu ◽

Li Chen ◽

Qin Fang ◽

Xiquan Jiang ◽

Yongkang Zhou

Keyword(s):

Experimental Technique ◽

High Strain ◽

Pure Shear ◽

Single Pulse ◽

Hopkinson Bar ◽

Combined Loading ◽

Strain Rates ◽

High Strain Rates ◽

Split Hopkinson Bar ◽

Split Hopkinson

Mechanical behavior of materials at medium and high strain rates (101∼104 s−1) is the foundation of developing mechanical theories, building material models, and promoting engineering design and construction. The torsional split Hopkinson bar (TSHB) is an effective experimental technique for measuring the pure shear mechanical properties of materials at high strain rates. In this study, the state-of-the-art in TSHB experimental technique is presented. Five typical types of TSHB loading mechanisms, i.e., prestored energy loading, explosive loading, direct impact loading, flywheel loading, and electromagnetic loading, were systematically reviewed. The TSHB fundamentals were outlined, which include elementary components, basic assumptions, working principles, the pulse shaping technique, specimen design, and the single-pulse loading technique. In addition, the combined loading and high/low temperature experimental techniques, which were developed based on TSHB, were also discussed in detail. Nearly all necessary elements for conducting a TSHB experiment and analyzing the experimental data were provided. Some research directions should be further pursued, such as extending the range of applicable materials and developing the combined loading techniques.

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