Numerical Study of Round-Robin Tests on the Split Hopkinson Pressure Bar Technique

2013 ◽  
Vol 535-536 ◽  
pp. 518-521 ◽  
Author(s):  
Muhammad A. Kariem ◽  
Dong Ruan ◽  
John H. Beynon
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Numerical Study ◽  
High Strength ◽  
Round Robin ◽  
Hopkinson Pressure Bar ◽  
Element Analysis ◽  
Acceptable Error ◽  
Aisi 4140 ◽  
Split Hopkinson ◽  
Pressure Bar

It is known that the split Hopkinson pressure bar (SHPB) technique has not been standardised yet. The standardised SHPB technique is necessary in order to provide guidelines for determining the intrinsic material properties. This paper examines whether consistent results can be achieved from various sets of SHPBs. Finite element analysis has been conducted using ANSYS/LS-DYNA. Numerical simulation of the round-robin tests was conducted to study the consistency of results for OFHC copper, which were obtained from three sets of apparatus, namely: 12.7 mm diameter SHPB made from the AISI 4140 steel, 13 mm diameter SHPB made from the high strength steel (HSS) and 14.5 mm diameter SHPB made from maraging steel 350 (AISI 18Ni). The current study shows that consistent flow stresses (within an acceptable error of 2.5%) were obtained from those three sets of SHPBs, which indicates the possibility of SHPB standardisation in the future.

scholarly journals Minimum Required Distance of Strain Gauge from Specimen for Measuring Transmitted Signal in Split Hopkinson Pressure Bar Test

2020 ◽  
Vol 308 ◽  
pp. 04005 ◽  
Author(s):  
Daesung Kim ◽  
Hyunho Shin
Keyword(s):  
Strain Gauge ◽  
Split Hopkinson Pressure Bar ◽  
Hopkinson Pressure Bar ◽  
Element Analysis ◽  
Design Modification ◽  
Explicit Finite Element ◽  
Specimen Diameter ◽  
Explicit Finite Element Analysis ◽  
Split Hopkinson ◽  
Pressure Bar

The minimum required distance of the strain gauge on the transmitted bar of the split Hopkinson bar has been determined from the position of a metallic specimen via an explicit finite element analysis. The minimum required distance was determined when the strain-time profiles at r = 0, 0.5Ro and 1.0Ro, were coincident (r is the radial position and Ro is the radius of the bar.). The determined minimum required distance, f(x), is presented as a function of the relative specimen diameter to that of the bar (x = D/D0): j(x) = - 0.9385.x3 + 0.6624.x2 - 0.7459.x + 1.4478 (0.1 ≤ x ≤ 0.9). This result demonstrates the Saint-Venant's principle of rapid dissipation of localized stress in transient loading. The result will be useful for the design/modification of the pseudo-one-dimensional impact instruments that utilise a stress pulse transmitted through the specimen. The result will also allow one to avoid unnecessarily remote strain gage position from the specimen.

An improved method for compressive stress-strain measurements at very high strain rates

1992 ◽  
Vol 438 (1902) ◽  
pp. 153-170 ◽  
Keyword(s):  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Pure Copper ◽  
High Strength ◽  
Tungsten Alloy ◽  
High Speed Photography ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Split Hopkinson ◽  
Pressure Bar

This paper describes a modification of the split Hopkinson pressure bar, to allow compression testing of high strength metals at a strain rate of up to about 10 5 s –1 . All dimensions are minimized to reduce effects of dispersion and inertia, with specimens of the order of 1 mm diameter. Strain is calculated from the stress record and calibrated with high-speed photography. Particular attention has been paid to the accuracy of the technique, and errors arising from nonlinearity in the instrumentation, dispersion, frictional restraint and inertia have all been quantitatively assessed. Stress–strain results are presented of Ti 6A14V alloy, a high strength tungsten alloy, and pure copper.

Experimental and Numerical Researches of Dynamic Failure of a High Strength Alumina/Boride Ceramic Composite

2008 ◽  
Vol 368-372 ◽  
pp. 713-716 ◽  
Author(s):  
Jiang Tao Zhang ◽  
Li Sheng Liu ◽  
Peng Cheng Zhai ◽  
Qing Jie Zhang
Keyword(s):  
Ceramic Composite ◽  
Failure Modes ◽  
Split Hopkinson Pressure Bar ◽  
Numerical Models ◽  
High Strength ◽  
Tensile Failure ◽  
Hopkinson Pressure Bar ◽  
Loading Direction ◽  
Split Hopkinson ◽  
Pressure Bar

The dynamic compressive behavior of Al2O3 (10% vol.) / TiB2 ceramic composite had been tested by using a split Hopkinson pressure bar in this paper. The results show that the main failure modes of the ceramic composite include crushed failure and split fracture along the loading direction. The former is the typical compressive failure of brittle materials. The later is tensile failure along the flaws produced during the composite manufacturing. The numerical simulation was also used to study the effect of the diameter/length ratio of the samples on the experimental results. The effect of the deformation in the bars’ ends, which contacted with the samples, was also studied in the numerical models.

Dynamic Response and Fracture of High Strength Boride/Alumina Ceramic Composite

2006 ◽  
Vol 326-328 ◽  
pp. 1573-1576
Author(s):  
Dong Feng Cao ◽  
Li Sheng Liu ◽  
Jiang Tao Zhang
Keyword(s):  
Dynamic Response ◽  
Ceramic Composite ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
High Strength ◽  
Alumina Ceramic ◽  
Hopkinson Pressure Bar ◽  
Dynamic Loadings ◽  
Split Hopkinson ◽  
Pressure Bar

Dynamic response and fracture of high strength boride/alumina ceramic composite were investigated by split Hopkinson pressure bar (SHPB) experiment in this paper. The compressive stress–strain curves and dynamic compression strength of the composites were tested. The surface’s microstructure of fractured composites were examined by using scanning electron microscope (SEM) to investigate the fracture mechanism. The results show that boride/alumina has high dynamic compressive strength and high Young’s modulus. The main fracture mode of the material is the fracture of the ceramic grains. The micro-voids and flaws, generated during the sintering and manufacturing of material and mechanical process of specimen, decrease the strength of the material because they provide the source of crack expansion when the material undergoes the dynamic loadings.

scholarly journals Large Deformation Behavior of High Strength Steel Under Extreme Loading Conditions: High Temperature and High Strain Rate Experiments and Modeling

2018 ◽  
Vol 183 ◽  
pp. 01053
Author(s):  
Xueyang Li ◽  
Christian C. Roth ◽  
Dirk Mohr
Keyword(s):  
Strain Hardening ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
High Strength ◽  
Fracture Initiation ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Temperature Dependent ◽  
Split Hopkinson ◽  
Pressure Bar

Plasticity and fracture experiments are carried out on flat smooth and notched tensile specimens extracted from DP800 steel sheets. A split Hopkinson pressure bar testing system equipped with a load inversion device is utilized to reach high strain rates. Temperature dependent experiments ranging from 20°C to 300°C are performed at quasi-static strain rates. The material exposes a monotonic strain hardening behaviour with a non-monotonic temperature dependency. The rate-independent material behaviour at room-temperature is described with a non-associated Hill’48 plasticity model and an Swift-Voce strain hardening. A machine learning based model is used multiplicatively to capture the rate and temperature responses. A good agreement between measured and simulated force-displacement curves as well as local surface is obtained. The loading paths to fracture are then extracted to facilitate further development of a temperature dependent fracture initiation model.

Confinement device to assess dynamic crushability of wood material

2017 ◽  
Vol 232 (8) ◽  
pp. 1418-1432 ◽  
Author(s):  
J Wouts ◽  
G Haugou ◽  
M Oudjene ◽  
H Naceur ◽  
D Coutellier
Keyword(s):  
Finite Element ◽  
Split Hopkinson Pressure Bar ◽  
Large Diameter ◽  
Hybrid Approach ◽  
Hopkinson Pressure Bar ◽  
Wood Material ◽  
Element Analysis ◽  
Multiaxial Stress State ◽  
Split Hopkinson ◽  
Pressure Bar

Cellular materials such as wood are widely and advantageously used as shock absorbers in various transport applications. The design and manufacturing of structures made of these materials require the knowledge of their dynamic compressive properties at various strain rates and stress states. Therefore, it is challenging to conduct dynamic multiaxial stress state experiments and especially on split-Hopkinson pressure bar apparatus where stress hardening increases as a function of velocity. This paper presents the so-called verification and validation methodology for confining solutions dedicated to impact on viscoelastic split-Hopkinson pressure bar system with large diameter bars. The method is a hybrid approach combining finite element analysis and an original experimental validation. Based on finite element results, particular attention is given to the mass, the material and the geometry to minimize the confining device influence on the propagation of elastic waves and thus on the material response of the tested specimens. It is essential to avoid spurious reflected waves at the new interfaces of the system in order to ensure the validity of the experimentation. The numerically predicted solutions are experimentally validated and preliminary results in the context of dynamic loadings using wood material are presented.

scholarly journals Behavior of Fiber-Reinforced Polymer-Confined High-Strength Concrete under Split-Hopkinson Pressure Bar (SHPB) Impact Compression

2019 ◽  
Vol 9 (14) ◽  
pp. 2830 ◽  
Author(s):  
Zhihong Xie ◽  
Zhijian Duan ◽  
Yongchang Guo ◽  
Xiang Li ◽  
Junjie Zeng
Keyword(s):  
High Strength Concrete ◽  
Split Hopkinson Pressure Bar ◽  
High Strength ◽  
Fiber Reinforced Polymer ◽  
Hopkinson Pressure Bar ◽  
Compression Performance ◽  
Strength Concrete ◽  
Reinforced Polymer ◽  
Split Hopkinson ◽  
Pressure Bar

Fiber-reinforced polymer (FRP) has become increasingly popular in repairing existing steel-reinforced concrete (RC) members or constructing new structures. Although the quasi-static axial compression performance of FRP-confined concrete (FCC) has been comprehensively studied, its dynamic compression performance is not well understood, especially the dynamic compressive behavior of FRP-confined high-strength concrete (FCHC). This paper presents an experimental program that consists of quasi-static compression tests and Split-Hopkinson Pressure Bar (SHPB) impact tests on FRP-confined high-strength concrete. The effects of the FRP types, FRP confinement stiffness, and strain rate on the impact resistance of FCHC are carefully studied. The experimental results show that the strain rate effect is evident for FRP-confined high-strength concrete and the existence of the FRP greatly improves the dynamic compressive strength of high-strength concrete. An existing strength model is modified for impact strength of FCHC and the predicted results are compared with the test results. The results and discussions show that the proposed model is accurate and superior to the existing models.

scholarly journals Dynamic Behavior of Aluminum Alloy Aw 5005 Undergoing Interfacial Friction and Specimen Configuration in Split Hopkinson Pressure Bar System at High Strain Rates and Temperatures

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4614 ◽  
Author(s):  
Amine Bendarma ◽  
Tomasz Jankowiak ◽  
Alexis Rusinek ◽  
Tomasz Lodygowski ◽  
Bin Jia ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Split Hopkinson Pressure Bar ◽  
Strain Rates ◽  
Compression Tests ◽  
Hopkinson Pressure Bar ◽  
Element Analysis ◽  
Wide Range ◽  
Temperature Experiment ◽  
Split Hopkinson ◽  
Pressure Bar

In this paper, experimental and numerical results of an aluminum alloy’s mechanical behavior are discussed. Over a wide range of strain rates (10−4 s−1 ≤ έ ≤ 103 s−1) the influence of the loading impact, velocity and temperature on the dynamic response of the material was analyzed. The interface friction effect on the material’s dynamic response is examined using a split Hopkinson pressure bar (SHPB) in a high temperature experiment using finite element analysis (FEA). The effect of different friction conditions between the specimen and the transmitted/incident bars in the SHPB system was examined using cylinder bulk specimens and cylinder plates defined with four-layer configurations. The results of these tests alongside the presented numerical simulations allow a better understanding of the phenomenon and reduces (minimizes) errors during compression tests at high and low strain rates with temperatures ranging from 21 to 300 °C.

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