Numerical Simulation of Stress Wave Propagation Induced by Cut Blasting in Multi-Media

2012 ◽  
Vol 249-250 ◽  
pp. 22-25
Author(s):  
Guo Liang Yang ◽  
Ren Shu Yang ◽  
Chuan Huo ◽  
Yu Long Che

Explosive blasting in rock and other media could induce strong shock wave. Near blasting zone, the blasting energy mainly break rock. Slightly far away from borehole, the blasting energy induces plastic damage. Farther afield, this kind of energy presents elastic deformation. In cut blasting, multi-boreholes initiate at the same time, multi-column stress waves occur superimpose and converge. Especially in multi-media, this process is extremely complex. Adopt numerical simulation method, set up multi-media model, which include weathered rock, highly weathered rock and plain fill. This paper simulated the propagation process of stress wave in these medias. Revealed the propagation mechanics of stress wave.

2011 ◽  
Vol 90-93 ◽  
pp. 738-743
Author(s):  
Xiao Yun Sun ◽  
Jiu Long Cheng ◽  
Yun Sheng Wang ◽  
Dong Fang Zhang

A numerical simulation method of the rock bolts non-destructive testing based on ANSYS is presented. ANSYS/ LS-DYNA which is a kind of software of rock bolts dynamic finite domain analysis is used to establish a three-dimension model, after sine curve excitation is loaded, the reflection curve of naked rock bolts, or rock bolts with different defects are got, and the relationship curve between elastic modulus and stress wave velocity are got correspondingly. Experiment result proved that the aboved method was satisfied to simulate the stress wave propagation and the reflection situation in the rock bolts.


2013 ◽  
Vol 860-863 ◽  
pp. 1416-1419
Author(s):  
Ri Guang Wei ◽  
Zhen Xiao Qu ◽  
Jian Qiang Gao

According to the structure and working principle of rotary air preheater,the heat transfer calculation model is set up with reasonable simplification. Combining with the design parameters of the rotary air preheater of a 400 t/h pulverized coal boiler unit ,the results of practical calculation show that the said thermodynamic calculation method not only has higher precision of calculation,but also can get the temperature distributions of the gas, air and heat surface in each cross-section of the rotary air preheater. The result of numerical simulation calculation tallies well with the original designed data. It can be used for the heat calculation both two-sectorial and three-sectorial air heater; it can be used for performance analysis of the regenerative air heater.


2011 ◽  
Vol 94-96 ◽  
pp. 397-401
Author(s):  
Ru Heng Wang ◽  
Hua Chuan Yao ◽  
Bin Jia ◽  
Lin Wang

Concrete is a typical kind of rate sensitive material. In this paper, the concrete specimens were tested in the SHPB experiment system. Based on H-J-C constitutive model, the SHPB experiment was simulated by LS-DANY. The stress-strain curves which were gat from numerical simulation in the LS-DANY were compared with the stress-strain curves which were gat from SHPB. The results showed that the H-J-C constitutive could simulate the dynamic characteristics of concrete both under room temperature. The result also showed that the concrete was strain rate sensitive. Based on the numerical simulation, the stress wave in the SHPB system was studied. The research of the numerical simulation showed that the stress waves tended to become stable after several oscillations in the incident bar. At the same time, stress wave of elements in r=0 (The distance of elements to the axis was 0) were bigger than the stress wave of r=0.5R (The distance to the axis was 0.5R) and r=R (The distance to the axis was R).


2013 ◽  
Vol 663 ◽  
pp. 655-660
Author(s):  
Zhen Hua Xie ◽  
Zheng Lan Yuan ◽  
Yu Zhang

Aiming at the generation of blasting fume in underground blind roadway, numerical simulation method was taken to obtain the diffusion law of the blasting fume. In accordance with the actual situation in Shachang mining area of Shouyun iron mine, the physical model and mathematical model were set up, computational grids were divided, and the boundary condition was established. The diffusion law of blasting fume and the completion time under different explosives dosage were simulated by Fluent. The laws of blasting fume diffusion and diffusion time changing with the amount of explosive in local fan forced ventilation were obtained. The results can provide a theoretical basis for the research of a reasonable and effective ventilation manner of blind roadway.


2014 ◽  
Vol 624 ◽  
pp. 267-271
Author(s):  
Zhu Hua Tan ◽  
Bo Zhang ◽  
Peng Cheng Zhai

The dynamic response of the square tube subjected to the impact of a mass was investigated by using experimental and numerical methods. The square tube was impacted by a mass at the velocity ranging from 5.09 m/s to 12.78 m/s, and different progressive buckling modes were obtained. The numerical simulation was also carried out to analyze the buckling mechanism of the square tube. The results show that there is obvious stress wave propagation and strain localization in the tube, which has a significant influence on the buckling mechanism of the tube. The stress wave and inertia of the mass play different roles at various impact velocities. And buckling mechanism at low velocity is mainly caused by stress wave, whereas the buckling mechanism at high velocity is resulted from the inertial of the mass.


2019 ◽  
Vol 14 (1) ◽  
pp. 116-125
Author(s):  
Makoto Shimomura ◽  
Wilfridus F. S. Banggur ◽  
Agoes Loeqman ◽  
◽  

Mt. Semeru (3676 m asl.) is an active volcano in Indonesia. Mt. Semeru has a specific topography i.e., a large straight scar in its south-east flank. The geometry of the scar is approx. 2 km in length and 300–500 m width. The scar is connected to three major drainage channels: the Kobokan River, the Kembar River, and the Bang River. On December 29, 2002, a pyroclastic flow (PF) with an approximate volume of 3.25 × 106m3was generated and it traveled 9–11 km along the Bang River. This pyroclastic flow was the largest among the ones generated from 2002–2003 eruptions of Mt. Semeru. All prior recorded pyroclastic flows traveled 1–2.5 km along the Kembar channel. Thus, this pyroclastic flow suddenly changed its flow path, and it traveled more than three times longer than its antecedents. To investigate the cause of the sudden change, a simulated reproduction of this pyroclastic flow was carried out by employing the numerical simulation method proposed by Yamashita and Miyamoto (1993). Due to the uncertainty of the volume of each pyroclastic flow and the temporal change of deposition thickness, a total of 12 simulation cases were set up, with variations in the number of sequence events, the duration of inflow at the upper reach of the flow, and the inter-granular friction factor. The simulation results showed that to explain the sudden change in flow path, the Kembar channel, around 3 km from the vent, has to be buried by antecedent pyroclastic flows. Furthermore, the individual volumes of the prior flows must be less than 0.25–1× 106m3, with an inflow duration of less than 1 min. The friction factor must be set to be 0.5. By using the most acceptable case, the simulated pyroclastic flows were in good agreement with observed results. The results implied that careful investigation and continuous monitoring of the area at 1500–2000 m asl. on the south-east flank of Mt. Semeru are important to prepare for future pyroclastic flows.


2008 ◽  
Vol 22 (09n11) ◽  
pp. 1215-1220
Author(s):  
SOTO AKI KIDA ◽  
KEITA FUKUSHIMA ◽  
MASAYA MATSUMOTO

Impact stress wave propagating through porous materials is investigated in order to examine the ability of the shock absorbing effect. The specimens are modeled as the porous medium with different porous diameters made of the acrylic resin plate. When these models are impacted with different impact velocities, the impact stress waves propagating before and after the porous parts are measured using the strain gages in the experiments. As the reduction effect of the impact stress wave propagating in the porous medium, we pay attention to the maximum stresses and the duration times from the histories of the impact stress waves. One-dimensional wave theory and dynamic element method simulated this model are applied in order to explain these phenomena.


2009 ◽  
Vol 407-408 ◽  
pp. 632-635
Author(s):  
Jia Yao ◽  
Wei Lu ◽  
Chun Shan Liu

The specification of the vibration cutting loading is a decision factor for the generation of stress wave and the stress wave propagation has a significant impact on its micro-mechanism. Making the stress waves’ generation in the cutting area of vibration cutting for entry point, the analysis of internal inflection wave, inflection fracture and dynamic stress intensity factor has been carried out, the simulation of vibration cutting has also been done by finite element method, the essential of energy concentrated role, shear angle increment and cutting quality improvement has been explained.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3677
Author(s):  
Diego Scaccabarozzi ◽  
Bortolino Saggin

This work describes the results of a test campaign aimed to measure the propagation of longitudinal, torsional, and flexural stress waves on a drill bit during percussive rock drilling. Although the stress wave propagation during percussive drilling has been extensively modeled and studied in the literature, its experimental characterization is poorly documented and generally limited to the detection of the longitudinal stress waves. The activity was performed under continuous drilling while varying three parameters, the type of concrete, the operator feeding force, and the drilling hammer rotational speed. It was found that axial stress wave frequencies and spectral amplitudes depend on the investigated parameters. Moreover, a relevant coupling between axial and torsional vibrations was evidenced, while negligible contribution was found from the bending modes. A finite element model of the drill bit and percussive element was developed to simulate the impact and the coupling between axial and torsional vibrations. A strong correlation was found between computed and measured axial stress spectra, but additional studies are required to achieve a satisfactory agreement between the measured and the simulated torque vibrations.


2018 ◽  
Vol 27 (2) ◽  
pp. 255-267
Author(s):  
Zhenqun Sang ◽  
Zhiping Deng ◽  
Jianglin Xi ◽  
Huibin Yao ◽  
Jiang Wu

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