scholarly journals Full-scale simulation and validation of bucket filling for a mining rope shovel by using a combined rigid FE-DEM granular material model

2020 ◽  
Author(s):  
Andreas Svanberg ◽  
Simon Larsson ◽  
Rikard Mäki ◽  
Pär Jonsén
Keyword(s):  
Numerical Model ◽  
Finite Elements ◽  
Granular Material ◽  
Mass Flow ◽  
Mass Measurement ◽  
Flow Behavior ◽  
Full Scale ◽  
Open Pit ◽  
Mining Equipment ◽  
Loading Process

Abstract Rope shovels and other heavy mining equipment used for loading fragmented rocks to extract minerals from the earth are used in almost every open pit mine. The optimization of the loading process is of enormous value due to the extremely large amount of material turn over. In this work, a full-scale numerical model of the loading process is developed. Granular material of copper ore is modeled in a combination of rigid finite elements for larger particles with complex shapes, and the discrete element method for smaller particles. A multi rigid body dynamic model, discretized with finite elements are used to model the rope shovel. Calibration of the numerical model for the granular material is performed via a new and unique experimental full-scale approach of analyzing waste rock pile angles with a height of approximately 15 m. In situ experimental data acquisition is performed during the loading process for validation of the model. After model validation, the influence of several loading variables such as bucket rake angle, velocity, and position from the pile are investigated and evaluated. When comparing the numerical model results with experimental mass measurement an excellent agreement was observed. Also, drone camera video recordings of the mass flow behavior and the numerical mass flow behavior are in agreement. Small adjustments of dig variables show a significant effect on the average dig force as well as the bucket fill factor.

scholarly journals A Multiple Criteria Decision Making Method to Weight the Sustainability Criteria of System Selection for Surface Mining

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3066
Author(s):  
Michał Patyk ◽  
Przemysław Bodziony ◽  
Zbigniew Krysa
Keyword(s):  
Decision Making ◽  
Performance Assessment ◽  
Multiple Criteria Decision Making ◽  
Surface Mining ◽  
Open Pit ◽  
Mining Equipment ◽  
Surface Mines ◽  
Mining Conditions ◽  
And Performance ◽  
Selection Of

Selection and assessment of mining equipment used in open pit rock mines relies chiefly on estimates of overall exploitation cost. The rational arrangement of mining equipment and systems comprising loading machines, haul trucks and crushing plants should be preceded by a thorough analysis of technical and economic aspects, such as investment outlays and the costs of further exploitation, which largely determine the costs of mining operations and the deposit value. Additionally, the operational parameters of the mining equipment ought to be considered. In this study, a universal set of evaluation criteria has been developed, and an evaluation method has been applied for the selection of surface mining equipment and the processing system to be operated in specific mining conditions, defined by the user. The objective of this study is to develop and apply the new methodology of multi-criteria selection of open pit rock mining equipment based on multiple criteria decision-making (MCDM) procedures, to enable the optimization of loading, handling and crushing processes. The methodology, underpinned by the principles of MCDM, provides the dedicated ranking procedures, including the ELECTRE III. The applied methodology allows the alternative options (variants) to be ranked accordingly. Ultimately, a more universal methodology is developed, applicable in other surface mines where geological and mining conditions are similar. It may prove particularly useful in selection and performance assessment of mining equipment and process line configurations in mining of low-quality rock deposits. Therefore, we undertook to develop universal criteria and applications for the selection and performance assessment of process machines for surface mines, taking into account environmental aspects as well as deposit quality.

Research and Analysis of the Sources of Emission of Respirable Fraction of Dust at the Coal Mines

2021 ◽  
pp. 65-70
Author(s):  
G.I. Korshunov ◽  
◽  
A.M. Safina ◽  
A.M. Karimov ◽  
◽  
...  
Keyword(s):  
Dust Emission ◽  
Dust Content ◽  
Open Pit ◽  
Fine Dust ◽  
Mining Equipment ◽  
Length Of Service ◽  
The Road ◽  
Urgent Task ◽  
Negative Effect ◽  
Dust Load

At the deposits of the Krasnoyarsk Territory, the actual concentration of the suspended dust is 60–83 mg/m3. The search for efficient ways of reducing dust emission and dust suppression remains an urgent task, since fine dust has a negative effect on the health of enterprise employees and on mining equipment reducing its service life. Full-scale measurements were conducted related to the dust content and dispersed composition of the aerosols. The dust content was measured by counting method with the use of CEM DT-9880 dust particle counter. The measurements were conducted at the points located at different distances from the road of the section. The content of the most dangerous fraction PM2.5 was 48 % of the total amount of fine dust or 30–40 mg/m3, while the maximum permissible concentration for this fraction is 0.16 mg/m3. The employees who constantly work near the automotive haul roads and the ruins of an exploded rock mass are exposed to the strongest effects of dust emissions on the respiratory organs. To reduce the dust load on the employees of the mining enterprise, it is most appropriate to deal primarily with the dust emitted from the open pit roads, since this will help to reduce the dust load by 30–40 %. The permissible length of service for the operator of the loading equipment of one of the open-pit mines of the Krasnoyarsk Territory was calculated: it will be 9 years, and not 17, as was obtained earlier — without considering the actual content of the respirable dust. With the most rational parameters of drilling and blasting operations and using all methods to reduce dust formation, it is possible to reduce the dust emission by 15–20 %.

scholarly journals Numerical modeling of reinforced concrete structures: static and dynamic analysis

2013 ◽  
Vol 66 (4) ◽  
pp. 425-430 ◽  
Author(s):  
Jorge Luis Palomino Tamayo ◽  
Armando Miguel Awruch ◽  
Inácio Benvegnu Morsch
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Finite Elements ◽  
Dynamic Analysis ◽  
Time Integration ◽  
Great Accuracy ◽  
Constitutive Law ◽  
Published Data ◽  
Static And Dynamic Analysis ◽  
Plates And Shells

A numerical model using the Finite Element Method (FEM) for the nonlinear static and dynamic analysis of reinforced concrete (RC) beams, plates and shells is presented in this work. For this purpose, computer programs based on plasticity theory and with crack monitoring capabilities are developed. The static analysis of RC shells up to failure load is carried out using 9-node degenerated shell finite elements while 20-node brick finite elements are used for dynamic applications. The elasto-plastic constitutive law for concrete is coupled with a strain-rate sensitive model in order to take into account high loading rate effect when transient loading is intended. The implicit Newmark scheme with predictor and corrector phases is used for time integration of the nonlinear system of equations. In both cases, the steel reinforcement is considered to be smeared and represented by membrane finite elements. Various benchmark examples are solved with the present numerical model and comparisons with other published data are performed. For all examples, the path failure, collapse loads and failure mechanism is reproduced with great accuracy.

scholarly journals Influence of foundation settlements in load redistribution on columns in a monitoring construction - Case Study

2010 ◽  
Vol 3 (3) ◽  
pp. 346-356 ◽  
Author(s):  
G. Savaris ◽  
P. H. Hallak ◽  
P. C. A. Maia
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Finite Elements ◽  
Load Distribution ◽  
Numerical Models ◽  
Normal Load ◽  
Finite Elements Method ◽  
Load Redistribution

The objective of this article is to present the results obtained in a study on the interaction between the behavior of the structure and the foundation settlements and verify the influence of normal load distribution on the columns. In this mechanism, known as structure soil interaction (SSI), as the building is constructed, a transfer of loads occurs from the columns which tend to settle more to those that tend to settle less. The study was conducted in a building which had its settlements monitored from the beginning of construction. For this purpose, a linear tridimensional numerical model was constructed and numerical analysis was performed, using the finite elements method. In these analyses, numerical models corre- sponding to the execution of each floor were used, considering the settlements measured in each stage of the construction. The results of analy- ses showed that the effect of SSI are significant for calculating the normal efforts on the columns, particularly on those located in the first floors.

scholarly journals Temperature parameters in the combustion chambers of CUMMINS KTA-50 engines operating on various fuels under different fuel consumption rates

2021 ◽  
Vol 315 ◽  
pp. 03011
Author(s):  
Georgiy Dubov ◽  
Alexander Bogomolov ◽  
Sergey Azikhanov ◽  
Pavel Strelnikov ◽  
Sergey Nokhrin
Keyword(s):  
Natural Gas ◽  
Fuel Consumption ◽  
Combustion Engine ◽  
Energy Charge ◽  
Motor Fuel ◽  
Liquefied Natural Gas ◽  
Open Pit ◽  
Mining Equipment ◽  
Evaporator Temperature ◽  
Dump Trucks

The issue of a comparative study of fuel consumption and temperature characteristics of gas-diesel BelAZ 75131 mining dump trucks equipped with an on-board cryogenic fuel system and hauling rock mass at the Kuzbass open-pit coal mine is considered in the article. A brief analysis of the efficiency of using liquefied natural gas (LNG) - methane - as a motor fuel for mining dump trucks is carried out. It is noted that the use of LNG fuel for heavy-duty dump trucks is one of the most promising ways to improve the environmental and economic performance during the operation of this type of mining equipment. The technique and instrumental base for conducting research are presented. The relationship between natural ratios of diesel fuel replacement with natural gas and the energy charge of these replacement is studied. The following data are presented: data on the consumption of vaporous (gaseous superheated) natural gas (hereinafter gaseous natural gas) during field operation of gas-diesel BelAZ 75131 mining dump trucks; flow rate of gaseous natural gas in pipelines; consumption of antifreeze at the inlet to the liquefied natural gas evaporator, as well as antifreeze temperature at the inlet and outlet of the evaporator; temperature of gaseous natural gas at the outlet of the reducer after the evaporator; data on the comparison of temperature profiles in the cylinders of CUMMINS KTA 50 internal combustion engine under diesel and gas-diesel operation.

scholarly journals Experimental and Numerical Evaluation of Progressive Collapse Behavior in Scaled RC Beam-Column Subassemblage

2016 ◽  
Vol 2016 ◽  
pp. 1-17 ◽  
Author(s):  
Rasool Ahmadi ◽  
Omid Rashidian ◽  
Reza Abbasnia ◽  
Foad Mohajeri Nav ◽  
Nima Usefi
Keyword(s):  
Numerical Model ◽  
Progressive Collapse ◽  
Experimental Tests ◽  
Resistance Mechanisms ◽  
Full Scale ◽  
Displacement Curve ◽  
Rc Beam ◽  
Rc Structures ◽  
Collapse Behavior ◽  
Column Removal Scenario

An experimental test was carried out on a 3/10 scale subassemblage in order to investigate the progressive collapse behavior of reinforced concrete (RC) structures. Investigation of alternative load paths and resistance mechanisms in scaled subassemblage and differences between the results of full-scale and scaled specimens are the main goals of this research. Main characteristics of specimen response including load-displacement curve, mechanism of formation and development of cracks, and failure mode of the scaled specimen had good agreement with the full-scale specimen. In order to provide a reliable numerical model for progressive collapse analysis of RC beam-column subassemblages, a macromodel was also developed. First, numerical model was validated with experimental tests in the literature. Then, experimental results in this study were compared with validated numerical results. It is shown that the proposed macromodel can provide a precise estimation of collapse behavior of RC subassemblages under the middle column removal scenario. In addition, for further evaluation, using the validated numerical model, parametric study of new subassemblages with different details, geometric and boundary conditions, was also done.

Numerical Towing Model for LNG Carrier Approach in Exposed Environment Calibrated With Full-Scale Measurements and Operability Criterion

2021 ◽  
Author(s):  
Erwan Auburtin ◽  
Quentin Delivré ◽  
Jason McConochie ◽  
Jim Brown ◽  
Yuriy Drobyshevski
Keyword(s):  
Numerical Model ◽  
Degrees Of Freedom ◽  
Line Tension ◽  
Full Scale ◽  
Model Parameters ◽  
Wave Loads ◽  
Simplified Approach ◽  
Large Matrix ◽  
Multi Body ◽  
The Impact

Abstract The Prelude Floating Liquefied Natural Gas (FLNG) platform is designed to offload liquefied natural and petroleum gas products to carrier vessels moored in a Side-by-Side (SBS) configuration. Prior to the mooring operation, the carrier vessel is escorted and held alongside the FLNG with the assistance of tugs connected to her bow and stern to ensure sufficient control over the vessel in this critical phase. In order to better understand the impact of environmental conditions, to determine the optimum length, strength, material and configuration of the towline stretcher, and to estimate the maximum operable environments, coupled multi-body simulations have been performed in time domain. The numerical model, which considered both the LNG carrier and the forward tug, was calibrated using full-scale measurements of tug motions and tow line tension recorded during a real approach and berthing manoeuvre at Prelude FLNG. The measured environment effects were generated numerically and the model parameters were adjusted to reproduce the recorded behavior as accurately as possible. Since actions of the tug master are difficult to model numerically and only the statistical environment parameters are known, a simplified approach has been adopted for modelling the tug propulsion and steering using a combination of static forces, stiffness and linear and quadratic damping for relevant horizontal degrees of freedom. The calibrated numerical model was first subjected to several sensitivity assessments of the modelling level (single- or multi-body, inclusion of second-order wave loads, inclusion of forward speed). Then sensitivity studies were performed to help address operational requirements related to the wave height and direction, and the stretcher length and strength. The conclusions have been taken into consideration for the selection of the tow line configurations for future operations. Finally, the calibrated coupled LNG carrier and tug model was used to derive Prelude-specific tug operability criteria that may be used for decision-making based on weather forecasts, prior to the SBS offloading operations. A large matrix of swell and wind driven waves was simulated over a range of wave heights, periods, directions and static towing forces to allow a criterion to be developed based on a stochastic extreme tow line tension. Such criterion considers relevant wave parameters while remaining simplified enough for easy use in operations. This paper describes the assumptions and process to numerically model the towing configuration and calibrate the different coefficients, discusses the results obtained for the various sensitivities, and explains the operability criteria. Important conclusions and lessons learnt are also shared.

On the Mass Flow Rate of Granular Material in Silos with Lateral Exit Holes

2012 ◽  
pp. 261-266
Author(s):  
Abraham Medina ◽  
G. Juliana Gutiérrez-Paredes ◽  
Satyan Chowdary ◽  
Anoop Kumar ◽  
K. Kesava Rao
Keyword(s):  
Granular Material ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate

Unsteady Responses of the Impeller of a Centrifugal Compressor Exposed to Pulsating Backpressure

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Mengying Shu ◽  
Mingyang Yang ◽  
Ricardo F. Martinez-Botas ◽  
Kangyao Deng ◽  
Lei Shi
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Centrifugal Compressor ◽  
Combustion Engine ◽  
Fluid Dynamic ◽  
Flow Behavior ◽  
Three Dimensional ◽  
Intake Manifold ◽  
Unsteady Simulation

The flow in intake manifold of a heavily downsized internal combustion engine has increased levels of unsteadiness due to the reduction of cylinder number and manifold arrangement. The turbocharger compressor is thus exposed to significant pulsating backpressure. This paper studies the response of a centrifugal compressor to this unsteadiness using an experimentally validated numerical method. A computational fluid dynamic (CFD) model with the volute and impeller is established and validated by experimental measurements. Following this, an unsteady three-dimensional (3D) simulation is conducted on a single passage imposed by the pulsating backpressure conditions, which are obtained by one-dimensional (1D) unsteady simulation. The performance of the rotor passage deviates from the steady performance and a hysteresis loop, which encapsulates the steady condition, is formed. Moreover, the unsteadiness of the impeller performance is enhanced as the mass flow rate reduces. The pulsating performance and flow structures near stall are more favorable than those seen at constant backpressure. The flow behavior at points with the same instantaneous mass flow rate is substantially different at different time locations on the pulse. The flow in the impeller is determined by not only the instantaneous boundary condition but also by the evolution history of flow field. This study provides insights in the influence of pulsating backpressure on compressor performance in actual engine situations, from which better turbo-engine matching might be benefited.

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