Numerical Simulation of Impact Process of Coal and Gangue

2011 ◽  
Vol 189-193 ◽  
pp. 953-957 ◽  
Author(s):  
Hao Jiang ◽  
Chang Long Du ◽  
Song Yong Liu ◽  
Jia Jia Zhang ◽  
Fei Liu

The difference of forcing status between coal and gangue in the process of impact was a fundamental problem in separation of them. In order to finding out forcing status of coal and gangue, the impact process was emulated by finite element software. The variation curves of contact force, the time-course curves of stress and pressure at different locations on material and board hammer were gained. The simulation results showed that for the different material properties, stress and pressure variation of coal were less than gangue, and the impact point in board hammer has the worst forcing status.

2010 ◽  
Vol 43 ◽  
pp. 666-669 ◽  
Author(s):  
Yu Liu ◽  
Chang Long Du ◽  
Jia Jia Zhang ◽  
Hao Jiang

The impact between spheres and planes was a fundamental problem in the objects impacts. The impact loads were investigated for the different materials spheres impacting on the different materials planes in this paper. The results of the impact between two elastic materials were consistent with the Hertz results, which indicated that the finite element model was accurate and reliable. The simulation results showed that the impact loads would decrease if there were plastic deformations during the impact. For the same material properties of the plane and the sphere, the impact loads of the plane were higher than ones of the sphere. In other words, the impact between the same materials made the plane prone to fail. If the material properties of the plane and the sphere were different, the impact loads and deformations were depended on the ratio of the contact stress and the yield limit. The material in elastic stage had the lower impact loads compared with one in plastic stage. The material with plastic deformations would keep some residual stress and offset after the contact.


2012 ◽  
Vol 538-541 ◽  
pp. 2887-2891
Author(s):  
Yu Qian ◽  
Xiao Jun Xiang ◽  
Jun Li Yang

To reduce the miss distance of flight test missile, the midcourse guidance law is studied in this paper. The nonlinear projectile dynamic model is developed at first, and then designed the midcourse guidance law with the impact point prediction information. The guidance law was designed using the difference between predicting impact point and target point. To improve the guidance law’s performance, this research inducted the predicted impact point’s velocity information and integral term into guidance law command. At the end, the simulation was developed. The results of simulation show that the guidance law designed in this study is successful and it can satisfy the test missile’s flight mission requirements.


2021 ◽  
Vol 906 (1) ◽  
pp. 012020
Author(s):  
Alexandr Zubov ◽  
Tatyana Shumilova

Abstract The Kara astrobleme is one of the largest astroblemes known on land. Its diameter is ~65 km, the age is about 70 million years. The astrobleme is located at the northeastern part of the Pay-Khoy anticlinorium at the Kara River mouth region (Kara Sea coast, Russia). It is a unique object of impact genesis due to the presence of a variety of suevites and melt impactites. Melt rocks are products of the highest degree of impact transformation of target rocks. The diversity of melt rock impactites of the Kara astrobleme and obtaining their complex comparative mineralogical and petrochemical characteristics are important for solving the fundamental problem for studying of the typomorphism of the impactitogenesis products of melt rocks both – the impactites of the Kara astrobleme and other astroblemes in general. In the Kara astrobleme region there are at list two different types of massive melt rocks bodies – a cover melt rock at the Anaroga River (I) studied by previous researchers and an unexplored body of melt rock impactite at the Kara River (II) spatially connected with ultrahigh-pressure high-temperature (UHPHT) glasses just recently discovered. Our preliminary data indicate that the melt rock varieties of the Kara astrobleme have significant differences in texture and structure. The considered melt rocks are mostly composed of a matrix represented by a “mixture” of amorphous and cryptocrystalline masses of predominantly feldspar composition with a subordinate SiO2 content. According to the data of energy dispersive analysis the compositions of the studied melt rocks are similar and have minor deviations within the first percent. The difference in the shape of silicate segregations in melt rocks may indicate that the impact melt could have a high temperature with a shorter time interval for the solidification of melt rock II on the Kara River, in contrast to the massive melt rock I on the Anaroga River, where the impact melt had large volume and, accordingly, was cooled longer at lower temperatures. The data obtained complement the specificity of the Kara melt impactites, which may play a role in complementing the geological model of the Kara astrobleme. The reported study was funded by RFBR, project number 20-35-90065; the analytical equipment has been used at the Center for Collective Use “Geonauka” (IG Komi FRC SC UB RAS, Syktyvkar, Russia); the author expresses his gratitude to Isaenko S.I. for analytical work using Raman spectroscopy; Tropnikov E.M. for help in performing microprobe studies.


2012 ◽  
Vol 28 (3) ◽  
pp. 258-270 ◽  
Author(s):  
Hideyuki Ishii ◽  
Toshio Yanagiya ◽  
Hisashi Naito ◽  
Shizuo Katamoto ◽  
Takeo Maruyama

The objective of this study was to investigate the factors affecting ball velocity at the final instant of the impact phase (t1) in full instep soccer kicking. Five experienced male university soccer players performed maximal full instep kicks for various foot impact points using a one-step approach. The kicking motions were captured two dimensionally by a high-speed camera at 2,500 fps. The theoretical equation of the ball velocity at t1 given in the article was derived based on the impact dynamics theory. The validity of the theoretical equation was verified by comparing the theoretical relationship between the impact point and the ball velocity with the experimental one. Using this theoretical equation, the relationship between the impact point and the ball velocity was simulated. The simulation results indicated that the ball velocity is more strongly affected by the foot velocity at the initial instant of the impact phase than by other factors. The simulation results also indicated that decreasing the ankle joint reaction force during ball impact shifts the impact point that produces the greatest ball velocity to the toe side and decreasing the ankle joint torque during ball impact shifts the impact point that produces the greatest ball velocity to the ankle side.


2014 ◽  
Vol 5 (1) ◽  
pp. 35-50
Author(s):  
Yudai Arai ◽  
Tomoko Kajiyama ◽  
Noritomo Ouchi

In light of the rapid growth of social networks around the world, this study analyses the impact of social networks on the diffusion of products and demonstrates the effective way to diffuse products in the society where social networks play an important role. We construct a consumer behaviour model by multi-agent simulation taking the movie market as an example. After validating it by using data from 13 US movies, we conduct simulations. Our simulation results show that the impact of social networks on the diffusion differs according to the customers’ expectations and evaluation for a movie. We also demonstrate the effective weekly advertising budget allocations corresponding to the types of movies. We find that the difference of weekly advertising budget allocations gives greater impact on the diffusion with the growth of social networks. This paper provides firm’s managers with important suggestions for diffusion strategy considering the impact of social networks.


2021 ◽  
Vol 349 ◽  
pp. 04005
Author(s):  
Boris Spak ◽  
Maximilian Schlicht ◽  
Karina Nowak ◽  
Markus Kästner ◽  
Pascal Froitzheim ◽  
...  

Joining by forming is a commonly applied technique in the automotive industry to assemble parts of thin metal sheets to meet the demands of lightweight design. The joining operation induces changes in material behaviour due to cold forming, that can be observed in increased hardness in the area close to the joint neck compared to the base material. Complex geometrical features of clinched joints on a small scale and the lack of non-destructive methods to track local stresses and strains require a combined approach utilizing numerical and experimental techniques. Numerical process and loading simulation are performed utilizing commercial finite element software LS-Dyna®. Hardness measurements in the joint are carried out to assess the impact of forming operation. Cyclic material properties are derived from Vickers hardness to estimate fatigue life with the Local Strain Approach using the damage parameter PSWT. Fatigue life estimation with failure criterion crack initiation obtained from simulation results is compared to those from experiments. The results obtained indicate that the Local Strain Approach is suitable for fatigue life estimations of clinched joints under constant amplitude loading as long as the influence of the forming process is considered.


2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jian Lin ◽  
Hua Cheng ◽  
Hai-bing Cai ◽  
Bin Tang ◽  
Guang-yong Cao

This paper addresses the difficult closure of a frozen wall in a coal mine shaft due to excessive seepage velocity in an aquifer when the aquifer is penetrated via the artificial freezing method. Based on hydrothermal coupling theory and considering the effect of decreased absolute porosity on seepage during the freezing process, a mathematical model of hydrothermal full-parameter coupling with a phase change is created. A shaft is used as a prototype, and COMSOL multiphysics finite element software is employed to perform a numerical simulation of the shaft freezing process at various stratum seepage velocities. The numerical simulation results are verified via a comparison with field measurement data. Based on the numerical simulation results, the impact of various underground water seepage velocities on the artificial frozen wall formation process with the seepage-temperature field coupling effect is analysed. Based on the analysis results, the recommended principles of the optimization design for a freezing plan are described as follows: first, the downstream area is closed to enable the water insulation effect, and second, the closure of the upstream area is expedited to reduce the total closure time of a frozen wall.


2013 ◽  
Vol 303-306 ◽  
pp. 2835-2838
Author(s):  
Wen Hua Du ◽  
Hui Wen Zhao ◽  
Cong Du ◽  
Da Wei Zhang

Model built for the bicycle, road and the driver and contact established between them is the core technological issue for the study of frame’s deformation and driver’s injury on the electric bike accidents. A rigid model of bicycle, road and obstacle is built by using ADAMS software, and the driver is as Hybrid Ⅲ body collision model by LifeMOD software. Contact between them is established, especially on the driver’s chest to handlebar. Base on the rigid-body collision theory, the collision point of head and the speed of the chest were compared with different speed in the range of 15-35km/h. The simulation results shows that the impact between the rider’s chest and handlebar is the main reason to the difference of rider’s dynamic behave. Simulation results verify the validity of this model and lays fundamentals for the study of driver injury in electric bicycle accidents.


2019 ◽  
Vol 103 (1) ◽  
pp. 003685041987774
Author(s):  
Senqing Jia ◽  
Fusheng Wang ◽  
Lingjun Yu ◽  
Zheng Wei ◽  
Bin Xu

By applying finite element software ANSYS/LS-DYNA, finite element models of front bulkhead and main cabin are established, which aims to assess the dynamic response of fuselage structures impacted by tire fragment under bursting mode. Besides, dynamic characteristics of the two fuselage structures impacted by tire fragment are simulated and critical damage velocities of each working condition are obtained. The results show that composite front bulkhead cannot bear the impact load of front tire fragment at the velocity of 100 m/s, but aluminum alloy front bulkhead can. Main cabin with two properties both can bear the impact loads of front and main tire fragments. When impacted by front tire fragment, critical damage velocity of front bulkhead is approximately half of that of main cabin, while critical damage velocity of aluminum alloy fuselage is larger than that of composite fuselage. However, when impacted by main tire fragment, critical damage velocity of aluminum alloy main cabin is less than that of composite main cabin. Furthermore, maximum contact pressure of composite fuselage is 3–3.3 times than that of aluminum alloy fuselage. The difference in concave deformation is not significant when impacted by front tire fragment, but the difference is great when impacted by main tire fragment.


2012 ◽  
Vol 268-270 ◽  
pp. 134-137
Author(s):  
Jin Li ◽  
Liang Yi Li ◽  
Zheng Yuan

This paper by cold isostatic pressing and sintering of combining the method of preparation of silicon carbide enhance aluminum functional gradient materials, and the microstructure, density, impact toughness are analyzed, the results of experiments showed that in the aluminum gradient to join in the silicon carbide enhance particles, The impact toughness of the material has been obviously improved. Using ANSYS Numerical simulation Impact process, the simulation results anastomosis with the experimental results.


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