Characteristics of morphology and tensile strength of asphalt mixtures under impact loading using split Hopkinson pressure bar

2020 ◽  
Vol 260 ◽  
pp. 120443
Author(s):  
Zhenliang Jiang ◽  
Changbin Hu ◽  
Ming Liu ◽  
Said M. Easa ◽  
Xiaoyan Zheng
Keyword(s):  
Tensile Strength ◽  
Impact Loading ◽  
Split Hopkinson Pressure Bar ◽  
Asphalt Mixtures ◽  
Hopkinson Pressure Bar ◽  
Split Hopkinson ◽  
Pressure Bar

scholarly journals Development of a True-Biaxial Split Hopkinson Pressure Bar Device and Its Application

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7298
Author(s):  
Shumeng Pang ◽  
Weijun Tao ◽  
Yingjing Liang ◽  
Shi Huan ◽  
Yijie Liu ◽  
...  
Keyword(s):  
Stress Wave ◽  
Impact Loading ◽  
Split Hopkinson Pressure Bar ◽  
Axial Stress ◽  
Dynamic Mechanical Properties ◽  
Stress Waves ◽  
Hopkinson Pressure Bar ◽  
Dynamic Mechanical ◽  
Split Hopkinson ◽  
Pressure Bar

Although highly desirable, the experimental technology of the dynamic mechanical properties of materials under multiaxial impact loading is rarely explored. In this study, a true-biaxial split Hopkinson pressure bar device is developed to achieve the biaxial synchronous impact loading of a specimen. A symmetrical wedge-shaped, dual-wave bar is designed to decompose a single stress wave into two independent and symmetric stress waves that eventually form an orthogonal system and load the specimen synchronously. Furthermore, a combination of ground gaskets and lubricant is employed to eliminate the shear stress wave and separate the coupling of the shear and axial stress waves propagating in bars. Some confirmatory and applied tests are carried out, and the results show not only the feasibility of this modified device but also the dynamic mechanical characteristics of specimens under biaxial impact loading. This novel technique is readily implementable and also has good application potential in material mechanics testing.

scholarly journals Dynamic tensile strength enhancement of concrete in split Hopkinson pressure bar test

2018 ◽  
Vol 10 (6) ◽  
pp. 168781401878230 ◽  
Author(s):  
Jingyi Chen ◽  
Da Xiang ◽  
Zhihua Wang ◽  
Guiying Wu ◽  
Genwei Wang
Keyword(s):  
Tensile Strength ◽  
Split Hopkinson Pressure Bar ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Dynamic Tensile Strength ◽  
Concrete Material ◽  
Split Hopkinson ◽  
Bar Test ◽  
Concrete Materials ◽  
Pressure Bar

Split Hopkinson pressure bar technique has been widely used to measure the dynamic tensile strength of concrete materials. Most experimental results show that the tensile strength of concrete material increases with strain rates. However, the dynamic tensile strength derived from the split Hopkinson pressure bar test is affected by lateral inertia confinement, which may lead to the overestimation of dynamic mechanical properties of concrete materials. The true dynamic characteristics of concrete materials are not actually shown by experimental data. It is impossible to completely eliminate the influence of lateral inertia confinement in split Hopkinson pressure bar tests. In this study, a rate-insensitive material model is used in commercial finite element software to study how the lateral inertia confinement affects the dynamic tensile strength of concrete material at strain rates between 30/s and 150/s. Comparison of finite element results and split Hopkinson pressure bar test results shows that the dynamic tensile strength enhancement of concrete materials is strongly influenced by the inertial effect. The dynamic increase factor of concrete materials which remove the influence of lateral inertia confinement in split Hopkinson pressure bar tests can reflect the true dynamic characteristics of concrete materials. It is also found that the influence of lateral inertia confinement is related to the size of the specimen.

Electro-Conductive Property of Polymeric Composite under Impact Loading Using a Modified SHPB

2011 ◽  
Vol 291-294 ◽  
pp. 1243-1246
Author(s):  
Jin Tao Lei ◽  
Ming Hua Zhang ◽  
Jian Kang Chen
Keyword(s):  
Impact Loading ◽  
Copper Foil ◽  
Split Hopkinson Pressure Bar ◽  
Polymeric Composite ◽  
Dynamic Strain ◽  
Hopkinson Pressure Bar ◽  
Testing Environment ◽  
Split Hopkinson ◽  
Conductive Property ◽  
Pressure Bar

In order to detect the variation of electro-conductive property of polymeric composite under impact loading, a modified split Hopkinson pressure bar (M-SHPB) is suggested. Such M-SHPB is constructed by designing a new test electrocircuit, and connecting it to the specimen and oscillograph. On the other hand, a copper foil cover is designed and placed on the whole SHPB equipment for avoiding interference of electromagnetic wave existing in the testing environment. By means of M-SHPB, the relation between the resistance and dynamic strain is effectively detected.

scholarly journals Dynamic Crack Propagation and Fracture Behavior of Pre-cracked Specimens under Impact Loading by Split Hopkinson Pressure Bar

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Shijun Zhao ◽  
Qing Zhang
Keyword(s):  
Crack Propagation ◽  
Impact Loading ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Crack Propagation ◽  
Dynamic Crack ◽  
Hopkinson Pressure Bar ◽  
Brazilian Disk ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Cracked Specimens

Deformation and fracture of brittle materials, especially crack propagation, have drawn wide attention in recent years. But dynamic crack propagation under impact loading was not well understood. In this paper, we experimentally tested Brazilian disk (BD) fine sandstone specimens containing pre-cracks under cyclic impact loading by the Φ 74 mm diameter split Hopkinson pressure bar (SHPB) test device. The pre-cracked specimens were named central straight through crack flattened Brazilian disk (CSCFBD). By using the low air-pressure loading conditions (0.1 MPa, equal to the impact velocity of 3.76 m/s), a series of dynamic impact tests were detected successfully, and the effects of pre-cracks on dynamic properties were analyzed. Experimental results show that the multiple cracks mostly initiate at/or near the pre-crack tips and then propagate in different paths and directions varying by inclination angles, leading to the ultimate failure. Compared to static or quasi-static loading, dynamic crack propagation and fracture behavior are obviously different. Furthermore, we characterized the crack propagation paths, directions, and fracture patterns and discussed the influences of the pre-cracks during the breakage process. We concluded that the results obtained are significant in investigating the failure mechanism and mechanical properties of brittle materials under impact loading.

Dynamic Tensile Test of Coal, Shale and Sandstone Using Split Hopkinson Pressure Bar

2012 ◽  
pp. 188-202
Author(s):  
Kaiwen Xia ◽  
Sheng Huang ◽  
Ajay Kumar Jha
Keyword(s):  
Tensile Strength ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Strength ◽  
Static Strength ◽  
Test Method ◽  
Hopkinson Pressure Bar ◽  
Dynamic Tensile Strength ◽  
Rock Samples ◽  
Split Hopkinson ◽  
Pressure Bar

The dynamic tensile strength plays a pivotal role in rock fragmentation affecting the overall economics under the present ‘Mine to Mill Concept’. In this paper, a modified SHPB technique and Brazilian test method is presented to test the dynamic tensile strength of coal, shale and sandstone rock samples collected from three opencast mines of Coal India Limited and is compared with the static strength value. The dynamic tensile strength of coal and rock is much higher than static strength and tensile strength of coal and rock samples increase with loading rate. The result shows that the dynamic strength of the coal sample is 1.5 times higher than static strength and the dynamic strength of the sandstone sample is 3 times higher than the static strength.

Study on Deformation Property of EPS Concrete Under Impact Loading

2011 ◽  
Vol 71-78 ◽  
pp. 809-814 ◽  
Author(s):  
Er Lei Bai ◽  
Jin Yu Xu ◽  
Zhi Gang Gao
Keyword(s):  
Strain Rate ◽  
Impact Loading ◽  
Deformation Property ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Rate Dependency ◽  
Hopkinson Pressure Bar ◽  
Average Strain Rate ◽  
Split Hopkinson ◽  
Pressure Bar

The EPS concrete with 10%，20%，30%，40%，50% EPS volume fraction were prepared. Taking critical strain as the index, the deformation property of EPS concrete with different EPS volume fraction under impact loading were studied using a 100-mm-diameter split Hopkinson pressure bar(SHPB) apparatus. The results show that the deformation property of the EPS concrete increases with the average strain rate for the strain rate effect, which takes on obvious strain rate dependency. For the EPS microscopic structure effect, the deformation property of the EPS concrete increases with the EPS volume fraction in 0~40%. Its deformation property reduces somewhat when the EPS volume fraction reaches 50%. To improve the deformation property, the optimum volume fraction of EPS is 40%.

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