scholarly journals Discrete Element Simulation Analysis of the Bending and Toppling Failure Mechanisms of High Rock Slopes

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhigang Meng ◽  
Yongli Hou ◽  
Longji Guo ◽  
Fengnian Wang ◽  
Kuiming Liu ◽  
...  
Keyword(s):  
Thin Layer ◽  
Simulation Analysis ◽  
Rock Joint ◽  
Discrete Element ◽  
Final State ◽  
Element Simulation ◽  
Straight Line ◽  
Toppling Failure ◽  
Strength Based ◽  
Crack Zone

The high rock slope situated in the Southwest stope of Taiping Mining, Inner Mongolia, is subject to dumping failure due to its instability. The dumping body rock layer of this stope shows obvious bending and lowering of the head. The overturning angle of the rock strata can reach 46°, and tension dislocation along the rock joint can be observed in exposed sections and at the bedding and lithologic interface. The sliding surface also displays a broken line morphology. Through evaluation of regional rock integrity parameters and rock soft and hard parameters, rock-mass strength based on Hoek Brown strength estimation criteria can be developed. Based on the discrete element method, the geological model of layered excavation of the thin layer slope can be constructed. Combined with indoor and outdoor assessments, the characteristics of toppling deformation of the thin layer open-air slope can be studied and summarized. In this study, simulation analysis showed that under first excavation conditions, a crack-, dump-, and antislip zone was formed. The rock in the crack zone formed a “<”-shaped fracture along the slope surface that was squeezed towards the bottom of the slope. In the lower dumping area, the deflection angle gradually increased with excavation, and the deformation range and levels in the antislip area increased with excavation. Following the third excavation, the antisliding zone disappeared and the toppling line changed from a broken line to a straight line. In the final state, the slope collapsed as a whole, with the collapse of the dumping body penetrating the top to the foot of the slope.

scholarly journals Design and Simulation of a Garlic Seed Metering Mechanism

Agriculture ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1239
Author(s):  
Huiping Guo ◽  
Yazhou Cao ◽  
Wenyuan Song ◽  
Jiao Zhang ◽  
Changlin Wang ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Discrete Element ◽  
Discrete Element Simulation ◽  
Simulation Test ◽  
Single Seed ◽  
Element Simulation ◽  
Unit Speed ◽  
Optimal Adjustment ◽  
Seed Metering Device ◽  
Qualification Rate

According to the agronomic requirements of garlic sowing, the garlic morphology is studied and a garlic seed metering mechanism with excellent seeding performance is designed. Based on this design, a new garlic seeding machine with an adjustable-size seeding device is developed to realize efficient single-seed metering and seeding of different varieties of garlic. Further, the design scheme of the garlic seeder prototype is established, with the key components of the garlic seeding being designed on the basis of the garlic seeding mechanism. To achieve garlic single-seed metering for different varieties of garlic, the optimal adjustment size of the garlic seed metering device is determined through discrete element simulation analysis. A field experiment confirms the effectiveness of applying the proposed garlic planter to field sowing in terms of the metrics of missing seed and multiple seed rates. The results of the discrete element simulation test reveal that an adjustment size of 40 mm yields the best single-seed metering performance. At an operating speed of 15–35 rpm, the metering device can achieve more than an 80% qualification rate of single-seed metering, with a unit speed of 0.628–1.465 m/s. Thus, the developed garlic seeding device meets the requirements of precision sowing in China and can effectively realize the mechanized planting of garlic.

scholarly journals Discrete Element Simulation Analysis of Vibratory Cleaning Device

2018 ◽  
Vol 439 ◽  
pp. 052004
Author(s):  
Lingran Ma ◽  
Shukun Cao ◽  
Heng Wang ◽  
Yi Cui ◽  
Zijian Cao ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Discrete Element ◽  
Discrete Element Simulation ◽  
Element Simulation ◽  
Cleaning Device

scholarly journals Research on Simulation Analysis Method of Microbial Cemented Sand Based on Discrete Element Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Yang Tang ◽  
Guobin Xu ◽  
Jijian Lian ◽  
Yue Yan ◽  
Dengfeng Fu ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Moment Tensor ◽  
Simulation Method ◽  
Discrete Element ◽  
Particle Flow Code ◽  
Discrete Element Simulation ◽  
Cemented Sand ◽  
Physical Experiments ◽  
Element Simulation ◽  
Probability Of Fracture

A simulation method for microbial cemented sand (MCS) based on the Two-Dimensional Particle Flow Code (PFC 2D) has been developed in this study. It consists of an identification of mesoscopic contact model for structural mesoscopic particles, development of morphological algorithm for irregular crystal particles, and classification and setting of mesoscopic parameters for compositional materials and particle size distribution simulation. Additionally, an acoustic emission algorithm based on moment tensor theory was developed for discrete element simulation analysis on fracture characteristic of cemented sand under the action of the force. The simulation method proposed in this article/paper may reflect the physical and mechanical characteristics of real microbial cemented sand based on physical experiments. Quantification of the fracture process of microbial cemented sand is possible by introducing a moment magnitude (MW) in discrete element simulation analysis. The material may have greater probability of fracture between the MW ranges of −6.8 and −6.6. The relationship between probability of fracture at different MWs and the MW follows the Gaussian curve. The research results are a new trial for fracture analysis on microbial cemented sand.

Screw Conveyor Design and Discrete Element Simulation Analysis of the Rice Mill

2014 ◽  
Vol 644-650 ◽  
pp. 689-692
Author(s):  
Yan Hua Shi ◽  
Guo Quan Zhang ◽  
Ning Zhang ◽  
Zhi Ping Huang
Keyword(s):  
Structural Design ◽  
Simulation Analysis ◽  
Discrete Element ◽  
Screw Conveyor ◽  
Discrete Element Simulation ◽  
Element Analysis ◽  
Element Simulation ◽  
Overall Stability ◽  
Important Field ◽  
Important Basis

During the rice mill structural design process, static analysis is an extremely important field, not only decide to what the structure size is, but also for the subsequent fatigue analysis, providing the basis for the overall stability analysis. In this paper, vertical screw conveyor vertical rice mill, rice discrete element analysis simulation under different speed, the internal movement of materials to simulate the process for improving the productivity of the vertical screw conveyor has a certain significance. Providing an important basis for further design optimization of the rice mill structure.

scholarly journals Simulation analysis and experiment of sampling process of wheel brush sampler based on discrete element method

2021 ◽  
Vol 2137 (1) ◽  
pp. 012058
Author(s):  
Qiming Wei ◽  
Ran Liu ◽  
Hua Zhang ◽  
Xingyuan Wu ◽  
Haitao Luo
Keyword(s):  
Optimization Design ◽  
Simulation Analysis ◽  
Discrete Element ◽  
Test System ◽  
Simulation Software ◽  
Discrete Element Simulation ◽  
Structure Selection ◽  
Sampling Process ◽  
Element Simulation ◽  
Driving Torque

Abstract In order to study the brush sweep sampling process through simulation analysis, the structure of the asteroid sampler is simplified on the basis of retaining the wheel brush. Soybean particles are selected as the verification sampling particles, and the physical and contact parameters of calibrated soybean particles are applied to the discrete element simulation software EDEM and the relationship between the sampling wheel brush speed and torque is analysed. At the same time, a set of wheel brush asteroid sampler ground torque test system is built to verify the accuracy of the discrete element simulation results. The results show that the driving torque of the sampling wheel brush is mutational in the process of sampling, and the faster the rotation speed of the sampling wheel brush, the more the mass of the collected particles, and the greater the driving torque required for the sampling wheel brush. This research provides a method basis for the structure selection and parameter optimization design of the asteroid sampler.

A Research of Shaft Modal Simulation Method Based on the Preloaded Angular Contact Ball Bearing

2013 ◽  
Vol 389 ◽  
pp. 364-370
Author(s):  
Bei Li ◽  
Jian Bin Zhang ◽  
Lu Sha Jiang
Keyword(s):  
Simulation Analysis ◽  
Simulation Method ◽  
Numerical Control ◽  
Angular Contact Ball Bearing ◽  
Tightening Force ◽  
Shaft System ◽  
Element Simulation ◽  
Rolling Element ◽  
Bearing Stiffness ◽  
Main Spindle

In order to analysis modal characteristic of bearing with pre-tightening force on main spindle of numerical control lathe, this paper proposes a model of spindle modality analysis. This model is used to simulate the preloaded bearing shaft system modal, and the simulation results are verified by modal experiment. This paper takes 7005c as the research object to establish the equivalent-spring model based on the Hertz theory considering the pre-tightening force, whose focus is dealing with the contact between bearings rolling element and raceway. Then the model will be used to get the bearing stiffness for finite element simulation analysis. The shafting modal with preloaded bearing test platform is structured to get the shaft system modal parameters, which is compared with and verified the simulation analysis.

scholarly journals 3-D Numerical Study of Mechanical Behaviors of Pile-Anchor System

2014 ◽  
Vol 580-583 ◽  
pp. 238-242
Author(s):  
Ri Cheng Liu ◽  
Bang Shu Xu ◽  
Bo Li ◽  
Yu Jing Jiang
Keyword(s):  
Simulation Analysis ◽  
Numerical Study ◽  
Bending Moments ◽  
Mechanical Behaviors ◽  
Foundation Pit ◽  
Anchor System ◽  
Anchor Cable ◽  
Axial Forces ◽  
Toppling Failure ◽  
Potential Failure

Mechanical behaviors of pile-soil effect and anchor-soil effect are significantly important in supporting engineering activities of foundation pit. In this paper, finite difference method (FDM) was utilized to perform the numerical simulation of pile-anchor system, composed of supporting piles and pre-stressed anchor cables. Numerical simulations were on the basis of the foundation pit of Jinan’s West Railway Station, and 3D simulation analysis of foundation pit has been prepared during the whole processes of excavation, supporting and construction. The paper also analyzed the changes of bending moments of piles and axial forces of cables, and discussed mechanical behaviors of pile-anchor system, through comparisons with field monitoring. The results show that the parameters concluding vertical gridding’s number, cohesion of pile and soil, and pile stiffness have robust influences on supporting elements’ behaviors. Mechanical behaviors of supporting pile and axial forces of anchor cable changed dramatically, indicating that the potential failure form was converted from toppling failure to sliding failure.

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