scholarly journals Antiknock Performance of Interlayered High-Damping-Rubber Blast Door under Thermobaric Shock Wave

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Xiudi Li ◽  
Chaoyang Miao ◽  
Qifan Wang ◽  
Zhengang Geng
Keyword(s):  
Shock Wave ◽  
Split Hopkinson Pressure Bar ◽  
Front Surface ◽  
Underground Structures ◽  
Hopkinson Pressure Bar ◽  
Maximum Displacement ◽  
Average Strain Rate ◽  
Split Hopkinson ◽  
High Damping Rubber ◽  
Pressure Bar

The long duration and high impulse shock wave of thermobaric bomb threatens the security of underground structures. To obtain high resistance blast door against thermobaric shock wave, firstly, the dynamic mechanic property of high damping rubber was studied by split Hopkinson pressure bar (SHPB) equipment and the stress-strain relationship of high damping rubber under average strain rate of 5200/s was obtained. Secondly, the numerical model of interlayered high-damping-rubber blast door was established with ANSYS/LS-DYNA code based on test results, and the antiknock performance of interlayered high-damping-rubber blast door under thermobaric shock wave was analyzed by contrast with ordinary blast door. The results showed that the midspan displacement of the blast door decreased firstly and then increased with the increase of thickness of the high-damping-rubber interlayer, and the optimal thickness of the high-damping-rubber interlayer for energy consuming was 150 mm in the calculation condition of this paper. With the increase of the distance between the interlayer and the front surface of the door, the midspan displacement of the blast door decreased continually. The midspan maximum displacement of interlayered high-damping-rubber blast door decreased 74.5% in comparison to ordinary blast door. It showed that the high-damping-rubber structure can effectively improve the antiknock performance of blast door under thermobaric shock wave.

scholarly journals Testing of Weakly Weathered Granites of Different Porosities Using a Split Hopkinson Pressure Bar Technique

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Lei Yan ◽  
Liansheng Liu ◽  
Shenghui Zhang ◽  
Depei Lan ◽  
Jiangchao Liu
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Peak Stress ◽  
Stress Waves ◽  
Porous Rocks ◽  
Average Strain ◽  
Hopkinson Pressure Bar ◽  
Average Strain Rate ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Damage Impact

Nuclear magnetic resonance (NMR) and damage impact testing, using a split Hopkinson pressure bar (SHPB) technique, were conducted on weakly weathered granites of different porosities. Based on this, this study determined and analysed the pore structure and distribution, propagation characteristics of stress waves, changes in initial tangent modulus, and energy dissipation in weakly weathered granites of different porosities. The research demonstrated that the nature of the internal porosity of weakly weathered granites changed with total porosity. Pore structure significantly influenced the amplitude of reflected waves and distortion of transmitted waves. Under constant-damage impact loads, the initial tangent modulus decreased with increasing porosity, whereas the stress-strain curves, after reaching the peak stress, had similar shapes. Peak stress and average strain rate showed a strong power-law correlation with porosity, and peak stress decreased in a power-law correlation with the increase of average strain rate. In other words, the difference in average strain resulted from different porosities when the incident energy was same, and the average strain was negatively correlated with porosity. Under damaging impact, the energy absorbed per unit volume decreased with increasing porosity. The research results reveal dynamic characteristics of natural porous rocks under damage impacts, which provide a reference for studying damage effects of porous rocks under the effects of stress waves.

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%.

Study on Toughening Effect in EPS Concrete

2011 ◽  
Vol 105-107 ◽  
pp. 1717-1722
Author(s):  
De Hui Zhao ◽  
Jin Yu Xu ◽  
Er Lei Bai
Keyword(s):  
Strain Rate ◽  
Volume Fraction ◽  
Split Hopkinson Pressure Bar ◽  
Plain Concrete ◽  
Rate Dependency ◽  
Hopkinson Pressure Bar ◽  
Effect Mechanism ◽  
Average Strain Rate ◽  
Split Hopkinson ◽  
Pressure Bar

To study on the toughing effect of EPS in the plain concrete, the EPS concrete with 10%,20%,30%,40%,50% EPS volume fraction were prepared. Taking specific energy absorption as the index, the toughing effect of EPS concrete with different EPS volume fraction under impact loading were studied using a 100-mm-diameter split Hopkinson pressure bar(SHPB) apparatus, and the toughing effect mechanism of the concrete was discussed. The results show that the toughing effect 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 toughing effect of the EPS concrete increases with the EPS volume fraction in 10~30%. Its toughing effect reduces somewhat when the EPS volume fraction reaches 40~50%. To improve the deformation property, the optimum volume fraction of EPS is 20%.

Analysis of the Impact of the Frequency Range of the Tensometer Bridge and Projectile Geometry on the Results of Measurements by the Split Hopkinson Pressure Bar Method

2013 ◽  
Vol 20 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Wojciech Moćko
Keyword(s):  
Test Bench ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Deformation ◽  
Spectral Width ◽  
Hopkinson Pressure Bar ◽  
Computing Environment ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
The Impact ◽  
Bench Model

Abstract The paper presents the results of the analysis of the striker shape impact on the shape of the mechanical elastic wave generated in the Hopkinson bar. The influence of the tensometer amplifier bandwidth on the stress-strain characteristics obtained in this method was analyzed too. For the purposes of analyzing under the computing environment ABAQUS / Explicit the test bench model was created, and then the analysis of the process of dynamic deformation of the specimen with specific mechanical parameters was carried out. Based on those tests, it was found that the geometry of the end of the striker has an effect on the form of the loading wave and the spectral width of the signal of that wave. Reduction of the striker end diameter reduces unwanted oscillations, however, adversely affects the time of strain rate stabilization. It was determined for the assumed test bench configuration that a tensometric measurement system with a bandwidth equal to 50 kHz is sufficient

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