scholarly journals Dynamic Compressive Strength Tests of Corroded SFRC Exposed to Drying–Wetting Cycles with a 37 mm Diameter SHPB

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2267
Author(s):  
Hui Chen ◽  
Xiangqiang Zhou ◽  
Qiang Li ◽  
Rui He ◽  
Xin Huang
Keyword(s):  
Strain Rate ◽  
Steel Fiber ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Strain Curve ◽  
Fiber Reinforced Concrete ◽  
Impact Compression ◽  
Dynamic Increase Factor ◽  
Compression Performance ◽  
The Impact

This study focuses on the dynamic compression performance of corroded steel fiber-reinforced concrete (SFRC) exposed to drying–wetting chloride cycles by a 37 mm diameter split Hopkinson pressure bar (SHPB) system. Three steel fiber contents (0.5%, 1.0%, 2.0%, by volume) were incorporated into concrete, and samples were subjected to drying–wetting cycles for different corrosion durations (30 days, 60 days, 90 days) after 28 days age. The sample damage mode, stress–strain curve and the dynamic compression performance of corroded SFRC were compared with plain concrete. Through the experimental data, strain-rate effect, fiber reinforcement effect and the corrosion duration influence on the impact compression property of SFRC were identified. The dynamic increase factor results of these samples were compared with the existing models in previous published literature. An empirical dynamic increase factor profile characterization model considering fiber content, corrosion duration and strain-rate is proposed.

scholarly journals Experimental Study on Dynamic Compression Characteristics of Red Sandstone under Wetting-Drying Cycles

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Bin Du ◽  
Haibo Bai ◽  
Minglei Zhai ◽  
Shixin He
Keyword(s):  
Compressive Strength ◽  
Fractal Dimension ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Degradation Mechanism ◽  
Impact Compression ◽  
Red Sandstone ◽  
Dynamic Compressive Strength ◽  
The Impact

To study the influence of wetting-drying cycles on dynamic mechanical properties of rock masses, the impact compression tests of red sandstone samples were carried out by using a split Hopkinson pressure bar (SHPB) apparatus with a diameter of 50 mm. The results showed that under the same number of wetting-drying cycles, the dynamic compressive strength of red sandstone increased exponentially with the strain rate, and the sensitivity of the strain rate decreased with the increase of wetting-drying cycles. The deterioration effect of wetting-drying cycles was significant, and the dynamic and static compressive strength decreased with the increase of wetting-drying cycles; the higher the strain rate, the stronger the sensitivity to wetting-drying cycles. Besides, the influence of wetting-drying cycles and strain rate was comprehensively studied, and the equation of dynamic compressive strength of red sandstone was obtained. After different wetting-drying cycles, the fractal characteristics of red sandstone dynamic fragmentation were obvious, and the fractal dimension was 2.02–2.80, and the fractal dimension increased logarithmically with the strain rate. Finally, the internal microstructure of red sandstone after different wetting-drying cycles was analyzed, and the degradation mechanism of the rock by the cycles was discussed.

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.

Damage Behavior of Steel Fiber Reinforced and Polymer Modified Concrete under Impact Loading

2007 ◽  
Vol 348-349 ◽  
pp. 889-892 ◽  
Author(s):  
Yi Ping Liu ◽  
Li Qun Tang ◽  
Xiao Qing Huang
Keyword(s):  
Impact Loading ◽  
Damage Evolution ◽  
Steel Fiber ◽  
Split Hopkinson Pressure Bar ◽  
Early Stage ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Polymer Modified Concrete ◽  
The Impact

Damage behaviors of plain concrete (PC), steel fiber reinforced concrete (SFRC), steel fiber reinforced and polymer modified concrete (SFRPMC) are studied in this paper by use of a Split Hopkinson Pressure Bar (SHPB). Three kinds of concrete materials appear obvious strain rate strengthening effects. SFRPMC appears a better resistance and energy absorption ability. A rate-dependent damage model is suggested to depict the impact damage evolution of three kinds of materials under different impact velocities. The simulation results showed the theoretical model could well describe the dynamic behaviors of the three kinds of materials, and steel fibers attribute more to resist crack develop in early stage, “bridge effect” of steel fibers slow up the damage evolution in SFRC, with the addition of polymer, the internal structures of SFRPMC were modified, SFRPMC gains better ductility, and appears a kind of “softening effect”, which makes the damage in SFRPMC develop more slowly than that in PC and SFRC under impact loading.

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.

Analysis of Failure Patterns and Damage Mechanisms under Impact Compression of Hybrid Fiber Reinforced Concrete

2012 ◽  
Vol 193-194 ◽  
pp. 609-613
Author(s):  
Meng Chen ◽  
Zhi Li ◽  
Zhe An Lu
Keyword(s):  
Reinforced Concrete ◽  
Failure Modes ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Fiber Reinforced Concrete ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Impact Compression ◽  
Failure Patterns ◽  
Compression Properties

In order to studying the failure patterns under impact compression of Hybrid Fiber Reinforced Concrete(HFRC), tests focused on static and dynamic compression properties according to steel fiber reinforced concrete(SFRC) and HFRC are adopted. The equipment of dynamic compression properties test is Ф74mm split Hopkinson pressure bar (SHPB). The static and dynamic compressive strength at four different strain rates of the two materials are obtained, while failure mechanism has been analyzed from specimens’ failure modes in static and dynamic compressive tests, which in turn provides theory basis for the application of HFRC.

Static and Dynamic Behaviors of Fibre Reinforced Recycled Aggregate Mortar

2021 ◽  
Vol 882 ◽  
pp. 237-246
Author(s):  
Sallehan Ismail ◽  
Mohamad Asri Abd Hamid ◽  
Zaiton Yaacob
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Impact Load ◽  
Dynamic Compression ◽  
Recycled Aggregate ◽  
Fibre Reinforcement ◽  
Hopkinson Pressure Bar ◽  
Loading Test ◽  
Dynamic Increase Factor ◽  
Hybrid Fibre ◽  
The Impact

This study aims to explore the inclusion of microfibre in fine recycled aggregate (FRA) mortars under dynamic impact load. A 12-mm-diameter Split Hopkinson Pressure Bar (SHPB) was employed to test the impact of a recycled mortar with a single and hybrid fibre system and to determine potential improvements in its dynamic mechanical properties. In recycled mortar production, two microfibres with different sizes and types, namely, polypropylene and nylon, were added whilst keeping the amount of microfibres at a volumetrical fraction of 0.6%. An impact loading test was conducted by using the striking bar of SHPB at impact speeds of 2, 4 and 6 m/s. The effects of fibre on failure mode, tensile curve, compressive strength and dynamic increase factor (DIF) were then analysed. Experimental findings show that the improved mortar fibre mix has superior quasi-static and dynamic compression power compared with the reference mortar mix. Meanwhile, compared with the single fibre mix, the hybrid fibre mix is more effective in enhancing the dynamic compressive ability of the recycled mortar. The recycled-hybrid-fibre-enhanced mortar showed lower DIF values compared with the reference mortar, and the inclusion of fibre reinforcement can reduce the fragmentation of the recycled mortar mix after being subjected to impact.

scholarly journals Dynamic Compression Damage Energy Consumption and Fractal Characteristics of Shale

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Guoliang Yang ◽  
Jingjiu Bi ◽  
Linian Ma
Keyword(s):  
Fractal Dimension ◽  
Energy Consumption ◽  
Energy Dissipation ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Compression ◽  
Fractal Theory ◽  
Dissipated Energy ◽  
Impact Tests ◽  
The Impact

Studying the relationship between energy consumption and crushed size of shale under different loading conditions is the key to efficient shale cracking. The split Hopkinson pressure bar system was used to study the dynamic mechanical properties of shale under parallel- and vertical-bedding loading, and energy dissipation in the impact tests was calculated. Relationships between the average crushed size of shale fracture products and energy dissipation and between the fractal dimension and dissipated energy were studied using fractal theory. The experimental results showed that the dynamic compressive strength of shale under parallel- and vertical-bedding conditions had an obvious positive correlation with the strain rate. Dissipative energy of the shale samples under loading in both directions increased with the increase of strain rate. The increase of the strain rate enhanced crushing of the sample. The vertical-bedding shale samples had stronger ability to absorb energy and more internal crack propagation. Dissipative energies of the shale samples in the parallel- and vertical-bedding impact tests were positively related to the fractal dimension. The fractal dimension increased with the increase of dissipative energy during sample failure; with further increase in the dissipative energy, its effect on the change of fractal dimension gradually weakened.

scholarly journals Breakage Characterization of Magnetite under Impact Loads and Cyclic Impact Loading

Energies ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 5459
Author(s):  
Liang Si ◽  
Yijun Cao ◽  
Guixia Fan
Keyword(s):  
Fractal Dimension ◽  
Strain Rate ◽  
Intergranular Fracture ◽  
Split Hopkinson Pressure Bar ◽  
Fractal Theory ◽  
Fracture Morphology ◽  
Impact Loads ◽  
Impact Compression ◽  
Cyclic Impact ◽  
The Impact

A series of impact compression tests were conducted to study the breakage characteristics of magnetite, as well as the impact pressure on its strain rate and dynamic compressive strength. The dynamic mechanical properties and fragmentation size distribution of magnetite under diverse impact loads and cyclic impact were investigated, with fractal theory as a basis and split Hopkinson pressure bar (SHPB). Breakage methods were also employed to analyze the fracture morphology of magnetite. According to the result, the fractal dimension can reflect the distribution of fragments in various sizes. If the strain rate increases, the fractal dimension will be larger, the fragment size will be finer, and the fragmentation degree will be more influential. A micro-analysis of SEM images demonstrates that the fracture morphology is determined by mineral properties. Under low load cyclic impact, intergranular fracture is the main fractography. Besides, the intergranular fracture will be changed to a transgranular one as the impact load increases.

The Free Plastic Compression of Pure Metals

1970 ◽  
Vol 37 (4) ◽  
pp. 1121-1126
Author(s):  
V. S. Shankhla ◽  
R. F. Scrutton
Keyword(s):  
Strain Rate ◽  
Dynamic Compression ◽  
Strain Curve ◽  
Initial Strain Rate ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Plastic Properties ◽  
Pure Lead ◽  
Pure Metals ◽  
The Impact

The dynamic compression of a billet by the impact of a falling weight is analyzed with reference to the general plastic properties of pure metals. Theoretical results are compared with the results of published experimental data for pure lead. It is shown that, for lead, the form of the stress-strain curve is little influenced by changes in strain rate during deformation. The strain-hardening coefficient is however found to be strongly influenced by the temperature changes associated with the adiabatic deformation. The position of the maximum in the stress-strain curve is sensitive to the value of the initial strain rate. A method is suggested whereby isothermal stress-strain relationships may be extended to include the effects of adiabatic thermal softening.

Experimental Study on Impact Compression and Spliting of Granite

2011 ◽  
Vol 117-119 ◽  
pp. 62-66
Author(s):  
Wan Peng Wang ◽  
Yong Le Hu ◽  
Xing Tao Ren ◽  
Yi Bo Xiong ◽  
Liang Ying
Keyword(s):  
Tensile Strength ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Failure Strain ◽  
Dynamic Compression ◽  
Tensile Failure ◽  
Experimental Result ◽  
Strain Rates ◽  
Dynamic Tensile Strength ◽  
Impact Compression

In order to systematically study on dynamic mechanics character of granite, impact compression experiments and impact flattened Brazilian disc specimens of granite have been investigated with modified split Hopkinson pressure bar (SHPB) experimental facility, curve about stress versus strain and other parameter at strain rates of 23.9/s～108.4/s were obtained from impact compression. The dynamic tensile strength and critical tensile failure strain at strain rates of 2.3/s～25.6/s were obtained from impact flattened Brazilian. The experimental result show that dynamic compression strength , elastic modulus and failure strain，dynamic tensile strength significantly increase comparing to quasi-static experiment, and the above mechanics parameter include dynamic strength etc will increase with strain rate increasing, granite have the character of impact harding and ductility enhancement. The failure degree of failure will increase with increasing strain rate under impact compression; the failure configurations of the specimens present an center splitting mode under impact flattened Brazilian experiments. Whether impact compression or impact splitting under strain rate including this paper ’s experiments, the relationship between the DIFC or DIFT and the logarithm of strain rate is linear.

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