scholarly journals Effects of Strain Rate and Initial Density on the Dynamic Mechanical Behaviour of Dry Calcareous Sand

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Zhangyong Zhao ◽  
Yanyu Qiu ◽  
Mingyang Wang
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Initial Density ◽  
Strain Rate Range ◽  
Hopkinson Pressure Bar ◽  
Calcareous Sand ◽  
Dynamic Mechanical ◽  
Mechanical Behaviours ◽  
Pressure Bar

The dynamic compressive behaviour of dry calcareous sand under rigid confinement was characterised using a split-Hopkinson pressure bar (SHPB). Sand samples were confined inside a sleeve of hardened stainless steel and capped by a pair of aluminium cylindrical rods. This assembly was subjected to repeated dynamic compaction to attain precise bulk mass densities. It was then sandwiched between the incident and transmission bars of SHPB for dynamic compression testing. Sand specimens of three initial mass densities, namely, 1.26 g/cm3, 1.35 g/cm3, and 1.42 g/cm3, were loaded by incident pulses applying a stress of 35 MPa, 71 MPa, and 143 MPa, respectively. Experimental results show that in the strain rate range of 335 s−1 to 1253 s−1, the dynamic mechanical behaviours of dry calcareous sands exhibited no significant strain rate effect. The Lundborg model and the Murnaghan model could be used to describe the deviatoric and volumetric behaviours of calcareous sand with different initial densities, respectively.

scholarly journals Study on the dynamic properties of AM-SLM AlSi10Mg alloy using the Split Hopkinson Pressure Bar (SHPB) technique

2018 ◽  
Vol 183 ◽  
pp. 04005 ◽  
Author(s):  
Bar Nurel ◽  
Moshe Nahmany ◽  
Adin Stern ◽  
Nahum Frage ◽  
Oren Sadot
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Static Mechanical ◽  
Split Hopkinson ◽  
Pressure Bar

Additive manufacturing by Selective Laser Melting of metals is attracting substantial attention, due to its advantages, such as short-time production of customized structures. This technique is useful for building complex components using a metallic pre-alloyed powder. One of the most used materials in AMSLM is AlSi10Mg powder. Additively manufactured AlSi10Mg may be used as a structural material and it static mechanical properties were widely investigated. Properties in the strain rates of 5×102–1.6×103 s-1 and at higher strain rates of 5×103 –105 s-1 have been also reported. The aim of this study is investigation of dynamic properties in the 7×102–8×103 s-1 strain rate range, using the split Hopkinson pressure bar technique. It was found that the dynamic properties at strain-rates of 1×103–3×103 s-1 depend on a build direction and affected by heat treatment. At higher and lower strain-rates the effect of build direction is limited. The anisotropic nature of the material was determined by the ellipticity of samples after the SHPB test. No strain rate sensitivity was observed.

A comparative study on dynamic mechanical performance of concrete and rock

2015 ◽  
Author(s):  
Xia Zhengbing ◽  
Zhang Kefeng ◽  
Deng Yanfeng ◽  
Ge Fuwen
Keyword(s):  
Mechanical Performance ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Peak Strain ◽  
Hopkinson Pressure Bar ◽  
Dynamic Mechanical ◽  
Strain And Strain Rate ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Relationship Of

Recently, engineering blasting is widely applied in projects such as rock mineral mining, construction of underground cavities and field-leveling excavation. Dynamic mechanical performance of rocks has been gradually attached importance both in China and abroad. Concrete and rock are two kinds of the most frequently used engineering materials and also frequently used as experimental objects currently. To compare dynamic mechanical performance of these two materials, this study performed dynamic compression test with five different strain rates on concrete and rock using Split Hopkinson Pressure Bar (SHPB) to obtain basic dynamic mechanical parameters of them and then summarized the relationship of dynamic compressive strength, peak strain and strain rate of two materials. Moreover, specific energy absorption is introduced to confirm dynamic damage mechanisms of concrete and rock materials. This work can not only help to improve working efficiency to the largest extent but also ensure the smooth development of engineering, providing rich theoretical guidance for development of related engineering in the future.

scholarly journals High strain rate behaviour of fiber reinforced concrete

2018 ◽  
Vol 183 ◽  
pp. 02012
Author(s):  
Miloslav Popovič ◽  
Jaroslav Buchar ◽  
Martina Drdlová
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Speed ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Fiber Reinforced Concrete ◽  
Hopkinson Pressure Bar ◽  
Static Test ◽  
Pressure Bar

The results of dynamic compression and tensile-splitting tests of concrete reinforced by randomly distributed short non – metallic fibres are presented. A Split Hopkinson Pressure Bar combined with a high-speed photographic system, was used to conduct dynamic Brazilian tests. Quasi static test show that the reinforcement of concrete by the non-metallic fibres leads to the improvement of mechanical properties at quasi static loading. This phenomenon was not observed at the high strain rate loading .Some explanation of this result is briefly outlined.

Dynamic Compression Performance of Reaction Sintering SiC/B4C Composite

2020 ◽  
Vol 999 ◽  
pp. 83-90
Author(s):  
Xiao Ju Gao ◽  
Hasigaowa ◽  
Meng Yong Sun ◽  
Cheng Dong Liao ◽  
Wei Ping Huang ◽  
...  
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Dynamic Strength ◽  
Reaction Sintering ◽  
Hopkinson Pressure Bar ◽  
Compression Performance ◽  
Loading Mode ◽  
Split Hopkinson ◽  
Pressure Bar

SiC/B4C composite was obtained using the reaction sintering method with Si infiltration, which exhibited excellent mechanical properties. The dynamic compressive response was investigated using a Split Hopkinson pressure bar at high strain rates ranging from 0.4×103 to 1.2×103 s-1. The results show that the dynamic strength of the SiC/B4C composite obtains a peak value at a strain rate of 1000/s, while its strain increased continuously with increasing strain rate. The dynamic loading mode of SiC/B4C composite exhibited three deformation regions, including an inelastic deformation region, rapid loading region and failure region. The dynamic failure mode of SiC/B4C composite depended upon the strain rate.

Modelling of Micro-Concrete Behaviour under Static and Dynamic Loading

2014 ◽  
Vol 584-586 ◽  
pp. 1089-1096
Author(s):  
Remdane Boutemeur ◽  
Mustapha Demidem ◽  
Abderrahim Bali ◽  
El Hadi Benyoussef
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Dynamic Tests ◽  
Hopkinson Pressure Bar ◽  
Proposed Model ◽  
Wide Range ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Static And Dynamic Loading

The aim of this study is to present a model for assessing the dynamic compression behaviour of a micro-concrete. This model is based on the results of numerous tests providing the developments of the mechanical characteristics of the material on a wide range of strain rate from 10-4s-1to 10+3s-1.The Split Hopkinson Pressure Bar (SHPB) dispositive, based on the wave propagation theory in materials, has-been adopted to carry out the dynamic tests on the investigated material. The proposed model is composed of two terms, each characterizing the different contributions noted in the two major explored areas of strain rate.

scholarly journals In-Situ Damage Evaluation of Pure Ice under High Rate Compressive Loading

Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1236 ◽  
Author(s):  
Isakov ◽  
Lange ◽  
Kilchert ◽  
May
Keyword(s):  
Strain Rate ◽  
High Speed ◽  
Split Hopkinson Pressure Bar ◽  
Compressive Loading ◽  
Compressive Load ◽  
Strain Rate Range ◽  
High Rate ◽  
Hopkinson Pressure Bar ◽  
Order Of Magnitude ◽  
Pressure Bar

The initiation and propagation of damage in pure ice specimens under high rate compressive loading at the strain rate range of 100 s−1 to 600 s−1 was studied by means of Split Hopkinson Pressure Bar measurements with incorporated high-speed videography. The results indicate that local cracks in specimens can form and propagate before the macroscopic stress maximum is reached. The estimated crack velocity was in the range of 500 m/s to 1300 m/s, i.e., lower than, but in similar order of magnitude as the elastic wave speed within ice. This gives reason to suspect that already at this strain rate the specimen is not deforming under perfect force equilibrium when the first cracks initiate and propagate. In addition, in contrast to quasi-static experiments, in the high rate experiments the specimens showed notable residual load carrying capacity after the maximum stress. This was related to dynamic effects in fractured ice particles, which allowed the specimen to carry compressive load even in a highly damaged state.

scholarly journals Modeling and Design of SHPB to Characterize Brittle Materials under Compression for High Strain Rates

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2191 ◽  
Author(s):  
Tomasz Jankowiak ◽  
Alexis Rusinek ◽  
George Z. Voyiadjis
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Brittle Materials ◽  
Material Strength ◽  
Strain Rates ◽  
Analytical Prediction ◽  
Hopkinson Pressure Bar ◽  
Finite Element Software ◽  
Pressure Bar

This paper presents an analytical prediction coupled with numerical simulations of a split Hopkinson pressure bar (SHPB) that could be used during further experiments to measure the dynamic compression strength of concrete. The current study combines experimental, modeling and numerical results, permitting an inverse method by which to validate measurements. An analytical prediction is conducted to determine the waves propagation present in SHPB using a one-dimensional theory and assuming a strain rate dependence of the material strength. This method can be used by designers of new SPHB experimental setups to predict compressive strength or strain rates reached during tests, or to check the consistencies of predicted results. Numerical simulation results obtained using LS-DYNA finite element software are also presented in this paper, and are used to compare the predictions with the analytical results. This work focuses on an SPHB setup that can accurately identify the strain rate sensitivities of concrete or brittle materials.

Effects of Temperature and Moisture on the High Strain Rate Compression Response of Graphite/Epoxy Composites

2003 ◽  
Vol 125 (4) ◽  
pp. 394-401 ◽  
Author(s):  
M. V. Hosur ◽  
S. M. Waliul Islam ◽  
U. K. Vaidya ◽  
P. K. Dutta ◽  
S. Jeelani
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Failure Modes ◽  
Elevated Temperatures ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Experimental Investigations ◽  
Hopkinson Pressure Bar ◽  
Pressure Bar

Experimental investigations were carried out on unidirectional Graphite/Epoxy laminate samples under dynamic compression loading using a modified Split Hopkinson Pressure Bar. High strain rate testing was carried out at room and elevated temperatures. 30 layered graphite/epoxy unidirectional laminates made using DA 4518U unidirectional prepregs system were fabricated. Tests were carried out on samples at room, 51.7°C, 121.1°C, and 190.6°C temperatures. Additional high strain rate tests were conducted on samples that were subjected to moist/freeze conditioning for 42 days. Failure modes were studied through scanning electron microscopy. Results of the study indicated plasticizing of matrix which was reflected through increased ductility of the samples as well as reduced slope of the stress-strain curves with the increase in temperature. Similar effect was evident in the samples that were subjected to moist/freeze conditioning.

The Effect of Specimen Size on the Dynamic Compressive Behaviour of Magnesium Alloy AZ31B

2013 ◽  
Vol 535-536 ◽  
pp. 141-144 ◽  
Author(s):  
Jing Xiao ◽  
Dong Wei Shu
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Slenderness Ratio ◽  
Specimen Size ◽  
Hopkinson Pressure Bar ◽  
Specimen Diameter ◽  
Split Hopkinson ◽  
Az31b Alloy ◽  
Pressure Bar

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.

Strain Rate Sensitivity of an Aluminium Alloy under Compressive Loads

2012 ◽  
Vol 548 ◽  
pp. 169-173 ◽  
Author(s):  
Nilamber K. Singh ◽  
Maloy K. Singha ◽  
Ezio Cadoni ◽  
Narinder K. Gupta
Keyword(s):  
Strain Rate ◽  
Aluminium Alloy ◽  
Split Hopkinson Pressure Bar ◽  
Testing Machine ◽  
Rate Sensitivity ◽  
Material Model ◽  
Strain Rate Range ◽  
Hopkinson Pressure Bar ◽  
Compressive Loads ◽  
Pressure Bar

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.

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