scholarly journals COMPUTER MODELING OF THE WORKING PROCESS OF A FOREST TRUCK EQUIPPED WITH HYDROPNEUMATIC SUSPENSIONS OF MODULAR TYPE

2021 ◽  
Author(s):  
Valeriy Posmetev ◽  
Vadim Nikonov ◽  
Viktor Posmetev
Keyword(s):  
Computer Modeling ◽  
Unit Length ◽  
Average Height ◽  
Vertical Acceleration ◽  
Working Process ◽  
Preliminary Assessment ◽  
Maintenance And Repair ◽  
Gas Cavity ◽  
Main Factors ◽  
The Cost

The influence of the constructive perfection of suspensions on the efficiency of the functioning of a logging vehicle in the process of hauling timber along insufficiently equipped logging roads has been substantiated. The current direction of improving the suspension of timber trucks, which allows to reduce fuel consumption, the cost of maintenance and repair, and, consequently, reduce the final cost of exported timber, is considered. A perspective scheme of a pneumohydraulic suspension of a modular type, applied to a timber truck, is proposed. On the basis of computer modeling, a preliminary assessment of the effectiveness of the functioning of the proposed pneumohydraulic suspension installed on a logging vehicle during its movement in the process of hauling timber along an insufficiently equipped logging road has been carried out. The main factors that have a significant impact on the operation of a pneumohydraulic suspension of a modular type are described. The dependences of the change in the maximum values of the vertical acceleration of the timber truck, the pressure in the gas cavity of the pneumohydraulic cylinder, the temperature difference on the average height of irregularities, the number of obstacles per unit length of the timber road and the speed of the timber truck are obtained. The numerical values of the main factors influencing the functioning of the proposed suspension are revealed, which provide the best effect when a timber truck is moving along an insufficiently equipped timber road.

scholarly journals EFFICIENCY ESTIMATION OF HYDRO-PNEUMATIC SUSPENSION OF A TIMBER TRUCK ACCORDING TO THE RESULTS OF SIMULATION MODELLING

2020 ◽  
Vol 10 (1) ◽  
pp. 218-232
Author(s):  
Valeriy Posmetev ◽  
Mikhail Drapalyuk ◽  
Vadim Nikonov ◽  
Viktor Posmetev ◽  
Aleksandr Avdyuhin
Keyword(s):  
Modular Design ◽  
Dimensional Space ◽  
Unit Length ◽  
Three Dimensional ◽  
Computer Experiments ◽  
Computer Experiment ◽  
Average Height ◽  
Vertical Acceleration ◽  
Gas Temperature ◽  
Time Step

The relevance of increasing the efficiency of timber transportation by forest transport vehicles through development of a promising hydropneumatic suspension scheme has been substantiated. A diagram of the proposed modular design suspension and logging vehicle equipped with this type of suspension has been presented. The results of its simulation have been also showed. A mathematical model of the movement of a six-wheeled timber truck in three-dimensional space has been developed to evaluate the use of such hydropneumatic suspensions in a forest car. The design scheme for constructing a timber truck dynamic model has been presented. The sequence of numerical integration at each time step has been described. It includes seven stages, repeated many times during the computer experiment. A computer program has been developed. It enables to investigate the coordinated operation of hydropneumatic suspensions and the influence of their parameters on the smooth running of a timber truck. Computer experiments have been carried out to overcome bumps and obstacles with given parameters at different speeds. The time dependences of the volume of the pneumatic cavity of the hydropneumatic suspension, pressure and gas temperature in it have been obtained. The influence of the average height of irregularities, the number of obstacles per unit length, the speed of timber truck on the maximum vertical acceleration of timber truck, the maximum pressure and temperature difference in the pneumatic cavity of the suspension under study has been revealed

scholarly journals Augmented Lagrangian preconditioners for the Oseen–Frank model of nematic and cholesteric liquid crystals

2021 ◽  
Author(s):  
Jingmin Xia ◽  
Patrick E. Farrell ◽  
Florian Wechsung
Keyword(s):  
Liquid Crystals ◽  
Augmented Lagrangian ◽  
Augmented Lagrangian Method ◽  
Mass Matrix ◽  
Unit Length ◽  
Mesh Size ◽  
Schur Complement ◽  
Cholesteric Liquid Crystals ◽  
Multigrid Algorithm ◽  
The Cost

AbstractWe propose a robust and efficient augmented Lagrangian-type preconditioner for solving linearizations of the Oseen–Frank model arising in nematic and cholesteric liquid crystals. By applying the augmented Lagrangian method, the Schur complement of the director block can be better approximated by the weighted mass matrix of the Lagrange multiplier, at the cost of making the augmented director block harder to solve. In order to solve the augmented director block, we develop a robust multigrid algorithm which includes an additive Schwarz relaxation that captures a pointwise version of the kernel of the semi-definite term. Furthermore, we prove that the augmented Lagrangian term improves the discrete enforcement of the unit-length constraint. Numerical experiments verify the efficiency of the algorithm and its robustness with respect to problem-related parameters (Frank constants and cholesteric pitch) and the mesh size.

Mechanical Analysis of Warm Extrusion Precision Forming on 42CrMo Steel Cutting Pick

2012 ◽  
Vol 538-541 ◽  
pp. 1061-1066 ◽  
Author(s):  
Chun Jian Su ◽  
Quan Lan Li ◽  
Lin Jing Xiao ◽  
Su Min Guo
Keyword(s):  
New Technology ◽  
Mechanical Analysis ◽  
Extrusion Force ◽  
Factors Affecting ◽  
42Crmo Steel ◽  
Pick Body ◽  
Mining Tool ◽  
Main Factors ◽  
The Cost ◽  
Warm Extrusion

Cutting pick is a kind of widely-used consumptive mining tool. The traditional producing technics of cutting pick body is foundry, or machining after roughly forging, or machining directly from metal bar. By former technics, the property of products is poor, and by latter, the material availability is low and the cost is high. The patent technology for cutting pick body warm extrusion introduced in this paper can overcome all the disadvantages mentioned above. In this paper, by analyzing the characteristic of cutting pick body warm extrusion, adopting the principle of power balance to solve the approximate solution of strain forces, the approximate calculating formulas of extruding power are deduced. The main factors affecting on extrusion force are determined theoretically. This research can be used as basis to design tooling and choose proper equipment for this new technology.

FEATURES OF BUSINESS VALUATION AND VALUE IN MODERN CONDITIONS

2020 ◽  
Author(s):  
A. R. Plotkina ◽  
A. A. Monin
Keyword(s):  
Analytical Data ◽  
Cash Flows ◽  
Business Valuation ◽  
Main Factors ◽  
The Cost

The paper considers the features of determining the cost and evaluating business in the new reality caused by the pandemic, highlights the main factors that affect the cost of business, and concludes that it is necessary to use various sources of analytical data to assess cash flows

Minimizing the cost of products manufactured by the assembly line

2020 ◽  
pp. 483-487
Author(s):  
N.I. Aristova
Keyword(s):  
Computer Modeling ◽  
Assembly Line ◽  
Scientific Research ◽  
The Self ◽  
Manufactured Products ◽  
The Cost ◽  
Assembly Operations ◽  
Automation Tools ◽  
Probabilistic Nature ◽  
Product Assembly

A significant criterion for the functioning of an assembly line is to minimize the cost of manufactured products, for the achievement of which approaches are currently used that apply computer modeling and the hierarchical principle of product assembly, the approach, as well as taking into account the probabilistic nature of the assembly operations. An overview of scientific research aimed at solving these problems is given. An approach has been proposed that makes it possible to assess the efficiency of production in the self-reproduction of automation tools by the criterion of minimizing the cost of manufactured products.

scholarly journals Computer Modeling of Barrel-Vaulted Sanctuary Exhibiting Flutter Echo with Comparison to Measurements

Acoustics ◽  
2020 ◽  
Vol 2 (1) ◽  
pp. 87-109
Author(s):  
Heather Lai ◽  
Brian Hamilton
Keyword(s):  
Computer Modeling ◽  
Architectural Design ◽  
Impulse Responses ◽  
Time Frequency ◽  
Geometrical Acoustics ◽  
Decay Times ◽  
Before And After ◽  
Show Evidence ◽  
Architectural Planning ◽  
The Cost

Computer modeling in acoustics allows for the prediction of acoustical defects and the evaluation of potential remediations. In this article, computer modeling is applied to the case of a barrel-vaulted sanctuary whose architectural design and construction led to severe flutter echoes along the main aisle, which was later mitigated through acoustical remediations. State-of-the-art geometrical acoustics and wave-based simulations are carried out to analyze the acoustics of this space, with a particular focus on the flutter echoes along the main aisle, before and after remediations. Multi-resolution wavelet and spectrogram analyses are carried out to isolate and characterize flutter echoes within measurements and computer-simulated room impulse responses. Comparisons of simulated responses to measurements are also made in terms of decay times and curves. Simulated room impulse responses from both geometrical acoustics and wave-based methods show evidence of flutter echoes matching measurements, to varying degrees. Time-frequency analyses isolating flutter echoes demonstrate better matches to measurements from wave-based simulated responses, at the cost of longer simulation times than geometrical acoustics simulations. This case study highlights the importance of computer modeling of acoustics in early design phases of architectural planning of worship spaces.

The planning, rationing and organization of work on technical maintenance of machinery and equipment in animal husbandry

2021 ◽  
pp. 58-67
Author(s):  
L. I. Kovalyev ◽  
I. L. Kovalyev ◽  
M. N. Kostomakhin
Keyword(s):  
Animal Husbandry ◽  
Dairy Farms ◽  
Technical Service ◽  
Average Total Cost ◽  
Highly Qualified ◽  
Maintenance And Repair ◽  
Total Cost ◽  
Service Contracts ◽  
Technical Maintenance ◽  
The Cost

Maintenance and repair of livestock machinery and equipment is carried out as a rule by specialized repair and service enterprises on the basis of service contracts in accordance with the procedure established by law. However, with the renewal of the park’s farms with machines and equipment with automated and computerized process control, as well as the reconstruction of dairy farms and complexes, it became necessary to have a production base and highly qualified specialists for the maintenance of equipment. The most important and key provisions of the improved methodology of planning and accounting of work in the technical service of animal husbandry with the use of a number of standards are given, some features of accounting and planning of these types of work have been noted. The concepts of “repair unit” and “category of complexity of technical service” have been defined. The general provisions of the methodology for calculating costs and determining the cost of carrying out maintenance and repair of livestock equipment have been considered. On the base of calculations, the average total cost standards for carrying out maintenance and repair of livestock equipment have been established. These standards greatly simplify the planning of costs during the operation of equipment, and also allow us to determine the cost of maintenance and repair at different stages of the creation of new machines.

Eutrophication

1972 ◽  
Vol 180 (1061) ◽  
pp. 371-382 ◽  
Keyword(s):  
Environmental Factors ◽  
Aquatic Ecosystems ◽  
Sewage Effluent ◽  
Large Reduction ◽  
Water Industry ◽  
Detailed Understanding ◽  
Run Off ◽  
Large Populations ◽  
Main Factors ◽  
The Cost

Eutrophication is enrichment by plant nutrients. Here man-made eutrophication is considered. The chief sources of enrichment are sewage, artificial fertilizers and agricultural wastes. Large populations of plants and animals, alive or dead, cause difficulties in the water industry and may interfere with recreation, especially fishing. Most of the phosphorus and nitrogen can be removed from sewage effluent if the cost is justified. A large reduction of agricultural run-off is impractical but some reduction is possible. The removal of polyphosphates from detergents is a palliative but a suitable replacement which does not pose a threat to the environment is not yet on the market. Though the main factors causing eutrophication are well known, there is little detailed understanding of their interaction with other environmental factors. Consequently it is not yet possible to forecast the exact changes to be expected in aquatic ecosystems, a fact which is illustrated by certain changes in two mildly enriched lakes over the last 27 years.

STUDY OF OPTICS FOR LED LIGHT DEVICES AND METHODS OF ITS COMPUTER MODELING

2020 ◽  
pp. 27-31
Author(s):  
I. I. Bayneva ◽  
N. S. Komarov
Keyword(s):  
Computer Modeling ◽  
Three Dimensional ◽  
Simulation Method ◽  
Optical Systems ◽  
Mathematical Methods ◽  
Optical Elements ◽  
Led Light ◽  
Secondary Use ◽  
Three Dimensional Models ◽  
The Cost

The article discusses optical systems for LED lighting devices, the principles of the propagation of rays in lenses of various designs. Analyzed the features of the secondary use of the optical elements in the form of lenses and prisms for different LED emission patterns in space. Considered the features and problems of calculation of the secondary optical systems. Problems and prospects of application are considered, research and computer modeling of optics, which is used to form the required light distribution in LED light devices. Computer modeling technologies and the mathematical methods that underlie them determine the possibility of developing such optical systems in lighting installations. The article considers the numerical Monte Carlo simulation method, which allows one to organize ray tracing modeling in optical systems. The TracePro software package for modeling and research of lighting devices and their optical elements allows you to automate the stage of their calculation and design, this significantly reduces the cost of developing new products. The prototyping of three-dimensional models of lens systems opens up great opportunities for manufacturers of optics for LEDs, allows research on prototypes planned for production of serial products.

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