scholarly journals Investigation of Energy Dissipation Behavior in Threaded Joints Under Impact Loading Using a Kolsky Tension Bar.

2017 ◽  
Author(s):  
Brett Sanborn ◽  
Bo Song
Keyword(s):  
Energy Dissipation ◽  
Impact Loading ◽  
Threaded Joints ◽  
Kolsky Tension Bar

scholarly journals Mechanical Response and Energy Dissipation Analysis of Heat-Treated Granite Under Repeated Impact Loading

2019 ◽  
Vol 59 (1) ◽  
pp. 275-296 ◽  
Author(s):  
Zhiliang Wang ◽  
Nuocheng Tian ◽  
Jianguo Wang ◽  
Shengqi Yang ◽  
Guang Liu
Keyword(s):  
Energy Dissipation ◽  
Impact Loading ◽  
Mechanical Response ◽  
Repeated Impact ◽  
Heat Treated

scholarly journals Study on Mechanical Properties and Energy Dissipation of Frozen Sandstone under Shock Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Lei Wang ◽  
Yue Qin ◽  
Haibin Jia ◽  
Hongming Su ◽  
Shiguan Chen
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Phase Change ◽  
Strain Rate ◽  
Impact Loading ◽  
Strengthening Effect ◽  
Red Sandstone ◽  
Water Ice ◽  
The Difference ◽  
Ice Phase

In order to understand the mechanical properties and energy dissipation law of frozen sandstone under impact loading, the cretaceous water-rich red sandstone was selected as the research object to conduct impact tests at different freezing temperatures (0°C, −10°C, −20°C, and −30°C). The test results suggested the following: (1) the peak stress and peak strain of frozen sandstone are positively correlated with strain rate and freezing temperature, and the strain rate strengthening effect and the low-temperature hardening effect are obvious. (2) The strain rate sensitivity of dynamic stress increase factor (DIF) is negatively correlated with temperature. Water-ice phase change and the difference in the cold shrinkage rate of rock matrix under strong impact loading will degrade the performance of rock together, so DIF is less than 1. (3) In the negative temperature range from −10°C to −30°C, DEIF is always greater than 1. The energy dissipation rate of red sandstone specimens fluctuated between 10% and 25% under the impact loading, and the data are discrete, showing obvious strain rate independence. The failure form changes from tensile failure to shear and particle crushing failure. (4) Combined with the micromechanism analysis, the difference in dynamic mechanical properties of red sandstone at different temperatures is caused by the water-ice phase change and the different cold shrinkage rates of the frozen rock medium. When the temperature drops from 0°C to −2°C, water migrates to the free space of the pore of frozen rock and freezes into ice crystal, resulting in frozen shrinkage. At −30°C, the expansion of ice dominates and the migration of water will stop, leading to frost heave.

scholarly journals Research on Fractal Characteristics and Energy Dissipation of Concrete Suffered Freeze-Thaw Cycle Action and Impact Loading

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2585 ◽  
Author(s):  
Yan Li ◽  
Yue Zhai ◽  
Xuyang Liu ◽  
Wenbiao Liang
Keyword(s):  
Fractal Dimension ◽  
Energy Consumption ◽  
Energy Dissipation ◽  
Impact Loading ◽  
Physical Parameters ◽  
Impact Compression ◽  
Freeze Thaw ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Fractal Characteristics

In order to study the fractal characteristics and energy dissipation of concrete suffered freeze-thaw cycle actions and impact loading, C35 concrete was taken as the research object in this paper, and freeze-thaw cycle tests were carried out with a freeze-thaw range of −20 °C~20 °C and a freeze-thaw frequency of 0~50 times. The degradation characteristics of concrete material and the variation rules of basic physical parameters under various freeze-thaw cycle conditions were obtained consequently. By using the SHPB (separated Hopkinson pressure bar) test device, impact compression tests of concrete specimens under different freeze-thaw cycle actions were developed, then the process of impact crushing and the mechanism of damage evolution were analyzed. Based on the screening statistical method and the fractal theory, the scale-mass distribution rules and fractal dimension characteristics of crushing blocks are investigated. Furthermore, the absorption energy, fracture energy and block kinetic energy of concrete under different conditions were calculated according to the energy dissipation principle of SHPB test. The relationship between the energy consumption density and the fractal dimension of fragments was established, and the coupling effect mechanism of freeze-thaw cycle action and strain rate effect on the fractal characteristics and energy consumption was revealed additionally. The research results show that the concrete under different freeze-thaw cycle conditions and impact loading speeds has fractal properties from the microscopic damage to the macroscopic fracture. The energy dissipation is intrinsically related to the fractal characteristics, and the energy consumption density increases with the increase of the fractal dimension under a certain freeze-thaw cycle condition. When at a certain loading speed, with the growth of freeze-thaw cycles, the energy consumption density reduces under the same fractal dimension, while the fractal dimension improves under the same energy consumption density.

scholarly journals Experiments on Mechanical Response and Energy Dissipation Behavior of Rockburst-Prone Coal Samples Under Impact Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Jinbao Tang ◽  
Sheng Li ◽  
Guangsheng Qin ◽  
Wanjie Lu ◽  
Zhijie Zhu ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Energy Dissipation ◽  
Strain Rate ◽  
Impact Loading ◽  
Mechanical Response ◽  
Peak Stress ◽  
Dynamic Elastic Modulus ◽  
Dissipated Energy ◽  
Peak Strain ◽  
Dynamic Mechanical

To reveal the dynamic mechanical response and energy dissipation behavior of rockburst-prone coal samples under impact loading, the compressive experiments on Xinzhouyao coals (prone) and Machang coals (nonprone) under different impact loadings were carried out using the Split Hopkinson Pressure Bar (SHPB). The dynamic mechanical properties were studied, including dynamic elastic modulus, strain rate, peak stress, peak strain, dynamic increment factor, and energy dissipation. The results show that the dynamic elastic modulus, peak stress, and peak strain of both prone and nonprone coals perform an obvious correlation with the increase of strain rate. The strain rate strengthening effect on the dynamic elastic modulus and compressive strength of rockburst-prone coal samples are more significant, reflected by the greater increment with the increase of strain rate, while the dynamic increment factors of both prone and nonprone coals show apparent strain rate strengthening. The incident, reflected, and transmitted energy of both two coals linearly increases with the impact velocity, although the increased rate may be different. The dissipated energy of rockburst-prone coal samples increases faster, while the rate of the increase of the dissipated energy is more stable with strain rate. The results may provide an important reference for revealing the failure law of engineering-scaled coal mass suffered by rockburst.

Effect of thermal treatment on energy dissipation of granite under cyclic impact loading

2019 ◽  
Vol 29 (2) ◽  
pp. 385-396 ◽  
Author(s):  
Rong-hua SHU ◽  
Tu-bing YIN ◽  
Xi-bing LI ◽  
Zhi-qiang YIN ◽  
Li-zhong TANG
Keyword(s):  
Energy Dissipation ◽  
Thermal Treatment ◽  
Impact Loading ◽  
Cyclic Impact Loading ◽  
Cyclic Impact
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