Study on Dynamic Mechanical Properties and Meso-Deterioration Mechanism of Sandstone Under Cyclic Impact Load

2019 ◽  
Vol 45 (5) ◽  
pp. 3863-3875
Author(s):  
Gang Wang ◽  
Yi Luo ◽  
Xinping Li ◽  
Tingting Liu ◽  
Mingnan Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Impact Load ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
Deterioration Mechanism ◽  
Cyclic Impact

scholarly journals Influence of Cyclic Impact Loading and Axial Stress on Dynamic Mechanical Properties of Burst-Prone Coal

2021 ◽  
Vol 2021 ◽  
pp. 1-10 ◽  
Author(s):  
Shuang Gong ◽  
Zhen Wang ◽  
Lei Zhou ◽  
Wen Wang
Keyword(s):  
Mechanical Properties ◽  
Impact Loading ◽  
Coal Sample ◽  
Impact Load ◽  
Axial Stress ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical ◽  
Cyclic Impact Loading ◽  
Cyclic Impact ◽  
The Impact

High in-situ stress and frequent dynamic disturbances caused by the mining process in deep coal mines can easily induce dynamic disasters such as coal burst. We conducted laboratory experiments to assess the effects of the axial stress loading and dynamic cyclic impact loading on the dynamic mechanical properties of burst-prone coals by using a modified split Hopkinson pressure bar (SHPB). Comparisons were made using two types of burst-prone and burst-resistant coal samples. The mineral components, organic macerals, and dynamic mechanical features of both burst-prone and burst-resistant coal samples were comparatively analyzed based on the obtained X-ray diffraction (XRD), optical microscope observations, and dynamic compressive stress-strain curves, respectively. The results of the microstructure analysis indicated a larger difference between the minimum and maximum reflectances of vitrinite for burst-prone coal. Compared to the burst-resistant coal samples, the burst-prone coals contained less corpocollinite and fusinite. While applying a high axial static load combined with cyclic impact load, the coal samples showed the characteristics of fatigue damage. The results also demonstrated that preaxial stress affected the burst resistance of coal samples. The greater the preaxial stress was, the less the coal samples could withstand the dynamic cyclic impact load. In comparison to the burst-resistant coal sample, the burst-prone coal sample showed a larger dynamic compressive strength and a lower deformation. They were also more positively capable of the propagation and activation of the coal burst. We believe that the results of the study are conducive to further understanding of the distribution of microcomponents of burst-prone coals. The results are also beneficial for realizing the dynamic mechanical characteristics of burst-prone coals under the impact of cyclic dynamic load.

scholarly journals Dynamic Mechanical Properties of Coals Subject to the Low Temperature-Impact Load Coupling Effect

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yanbing Wang ◽  
Yang Yang ◽  
Yuantong Zhang ◽  
Jianguo Wang
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Impact Load ◽  
Coupling Effect ◽  
Dynamic Mechanical Properties ◽  
Strength Properties ◽  
Coal Specimen ◽  
Dynamic Mechanical ◽  
Temperature Impact ◽  
The Law

AbstractThe effects of low temperature gradient on dynamic mechanical properties of coal were examined through Split-Hopkinson Pressure Bar (SHPB) Dynamic Impact Experiment, the law of dynamic mechanical parameters of coal specimen changing from room temperature to negative temperature (25 °C, −5 °C, −10 °C, −15 °C, −20 °C, −30 °C, −40 °C) was analyzed, and the coal-rock stress-strain curve characteristics subject to the low temperature-impact load coupling effect was discussed. The law of the effects of different strain rates on the rock strength properties and the compressive deformation and failure was analyzed by studying the coal specimen at −15 °C. Moreover, the mechanical properties of coal specimen in saturated and dry conditions were compared, and the effects of water and water-ice phase transition on the strength properties of the corresponding coal specimen were analyzed.

The Dynamic Mechanical Properties Study of Aluminum Alloy Honeycomb Material and its Numerical Simulation

2010 ◽  
Vol 452-453 ◽  
pp. 305-308
Author(s):  
Guang Ping Zou ◽  
Zhong Liang Chang ◽  
Xin Zheng Wang ◽  
Bao Jun Liu ◽  
Si Chen
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Aluminum Alloy ◽  
Impact Load ◽  
Simulation Method ◽  
Dynamic Mechanical Properties ◽  
Dynamic Strain ◽  
Dynamic Mechanical ◽  
Specific Strength ◽  
Aluminum Alloy Honeycomb

Light weight aluminum alloy honeycomb materials are ideal lightweight structure materials, which have higher specific strength and stiffness, and widely applied in aviation, aerospace, automobile and so on, and also it is an ideal material for damping, buffering, heat insulation and energy absorption. In this paper, the SHPB technique which the aluminum alloy bar diameter is 37mm is used for studying the dynamic mechanics property of the lightweight aluminum alloy honeycomb materials which the diameter is 30mm, and then to study the dynamic mechanical properties of the material, from the results we can see dynamic strain-stress curves can be divided into three phases, elastic phase, stress platform and compaction phase. And the numerical simulation method was used for study the dynamic deformation process of the honeycomb panel material under impact load, and also compare the results with the specimen cell figures which were observed by the microscope.

Polyurethanes based on hydroxylated rapeseed oil: thermal and dynamic mechanical properties

2015 ◽  
Vol 37 (2) ◽  
pp. 162-167
Author(s):  
V.A. Vilensky ◽  
◽  
L.V. Kobrina ◽  
S.V. Riabov ◽  
Y.Y. Kercha ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Rapeseed Oil ◽  
Dynamic Mechanical Properties ◽  
Dynamic Mechanical
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