Papers by Keyword: Split Hopkinson Pressure Bar (SHPB)

Abstract: An experimental investigation on the strain rate sensitivity of die steel (D3) has been presented in this paper at different rates (0.001-2500s-1) of uni-axial compression. Quasi-static tests (0.001s-1) of the material are conducted on universal testing machine (UTM), whereas, the experiments at high strain rates are performed on split Hopkinson pressure bar (SHPB) apparatus. The effects of gauge length of the specimen on the material properties of the material are studied at different strain rates. The material parameters of existing Cowper-Symonds and Johnson-Cook material models are determined and the suitability of the models is examined.

Abstract: The current research concentrates on the characterization of the mechanical behavior of Ti-6Al-2Sn-4Zr-6Mo alloy. The material was studied in compression using the Split Hopkinson Pressure Bar (SHPB) equipment at high strain rates and conventional servohydraulic materials testing devices at low strain rates. The tests were performed at temperatures ranging from room temperature up to 600 °C. According to the results of the compression tests, the strain hardening rate of the studied material decreases strongly with increasing strain rate. The observed strong decrease in the strain hardening rate with increasing strain rate is a consequence of the extremely strong adiabatic heating of the material due to its high strength and low thermal conductivity. In this study, the Johnson-Cook material model parameters were obtained from isothermal stress-strain curves that were calculated from the experimental (adiabatic) stress-strain data. In this paper, the results of the mechanical testing at high strain rates and the numerical modeling of the material behavior are presented and discussed in details.

Abstract: In this paper, an attempt has been made to study the dynamic mechanic properties of vulcanized rubber material which is used for industrial structure. A split Hopkinson pressure bar (SHPB) is utilized to obtain uniaxial compression response of the vulcanized rubber material under different strain-rate and temperatures loading conditions. The stress-strain curves under different conditions are obtained, which can be used as a basis for the data analysis procedure. It is found that the dynamic compressive strength of vulcanized rubber improves with the increase of strain-rate. And it is also significantly higher at low temperature than that at normal temperature，which is opposite from stiffness. Vulcanized rubber exhibits excellent superelasticity at temperature of -40°C that is noted as well.

Abstract: An experimental investigation on the dynamic compressive behaviour of the aluminium alloy, AA6063-T6 in the strain rate range from 0.001s^-1 to 850s^-1 is reported here. Cylindrical specimens of AA6063-T6 are tested under universal testing machine at quasi-static (0.001s-1) condition, whereas, experiments at high strain rates (110s-1,400s^-1,550s^-1,700s^-1 and 850s^-1) are conducted on the traditional split Hopkinson pressure bar setup. The strain hardening in the material is found to increase with increasing strain rate. It is observed that the existing Johnson-Cook material model with appropriate material parameters predicts the dynamic compressive flow stress of AA6063-T3 aluminium alloy precisely.

Abstract: A 74-mm-diameter split Hopkinson pressure bar (SHPB) is used to test the dynamic mechanical behavior of concrete and cement mortar. Experimental results show that concrete and cement mortar are rate-dependent. The load-carrying capacity of concrete is higher than that of cement mortar. Whereas, the maximum strain of concrete is lower than that of cement mortar. No matter for concrete or cement mortar, with the increase of impact velocity, the fragment size of specimens after experiment decreases.

Abstract: This paper first studied aluminum alloy honeycomb sandwich panel in out- plane static compress test.Through analyzing deformation characteristics, the loads-displacement relationship was obtained and are described by the average stress-strain curve. Secondly, using the Split Hopkinson Pressure Bar device of impact test, deformation behaviour，dynamic average stress-strain curve data and so on were got under different loading rates, thus learned impact dynamics characteristics of that.

Abstract: The dynamic compression tests of reinforced concrete with different reinforcement ratios are carried out by split Hopkinson pressure bar (SHPB). Reinforced steel bar is placed along longitudinal and transverse direction. Experimental results show that reinforced concrete is non-linear and rate-dependent. With the enhancement of strain rate, the peak stress of reinforced concrete increases correspondingly

Abstract: The purpose of the present paper is to investigate the mechanical properties of multi phase 800 high yield strength (MP800HY) steel under compressive loading at different strain rates (-4700s^-1 to-0.001s^-1). Specimens of MP800HY steel are tested on universal testing machine to study their stress-strain behavior under quasi-static (-0.001s^-1) condition. Then, the specimens are tested under split Hopkinson pressure bar (SHPB) to study the strain rate sensitivity of the material under different rates of compressive loading (-4700s^-1, -4300 1/s, -3800 1/s, -2900s^-1 and-1600s^-1). The effect of pulse shaper in SHPB experiments has been studied. Thereafter, the applicability of the existing Johnson-Cook material model to represent the flow stress of MP800HY is examined.

Abstract: Recently developed bulk metallic glass (BMG) alloys have attractive mechanical properties for structural applications, and tungsten fiber reinforced bulk metallic glass matrix composite(BMGC) would further improve the properties compared to un-reinforced BMG. With INSTRON1196 test machine system and SHPB experimental system, quasi-static and dynamic compression experiments on tungsten fiber reinforced bulk metallic glass matrix composite were carried out. The material flow stress is about 2200MPa in quasi-static, and the dynamic flow stress of the material is around 2800MPa with strain rate of 740 s^-1. The specimen fails with the form of axial cracks

Abstract: Industrial applications of Ti-based alloys, especially in aerospace, marine and offshore industries, have grown significantly over the years primarily due to their high strength, light weight as well as good fatigue and corrosion-resistance properties. A combination of experimental and numerical studies is necessary to predict a material behavior of such alloys under high strain-rate conditions characterized also by a high level of strains accompanied by high temperatures. A Split Hopkinson Pressure Bar (SHPB) technique is a commonly used experimental method to characterize a dynamic stress-strain response of materials at high strain rates. In a SHPB test, the striker bar is shot against the free end of the incident stress bar, which on impact generates a stress pulse propagating in the incident bar towards the specimen sandwiched between the incident and transmitted bars. An experimental study and a numerical analysis based on a three-dimensional finite element model of the SHPB experiment are performed in this study to assess various features of the underlying mechanics of deformation processes of the alloy tested at high-strain and -strain-rate regimes.