scholarly journals Simulation of rod vibrations process with an independent pendular suspension and vertical stabilization system

2018 ◽  
Vol 56 (4) ◽  
pp. 469-480
Author(s):  
I. S. Kruk ◽  
A. A. Tiunchik ◽  
V. Romanyuk
Keyword(s):  
Technological Process ◽  
Initial Conditions ◽  
Vertical Movement ◽  
Design Stage ◽  
Geometrical Parameters ◽  
Stabilization System ◽  
Special Approach ◽  
Rod Structures ◽  
Design And Testing

Continuous improvement of field sprayer design aimed at performance increase by increasing the working width, requires a special approach to ensure reliability of the supporting rod structure and quality of technological process. The question of rod vibrations, which arise when the driving systems copy field rough surface and abrupt changes in speed of the unit, remains topical. At the design stage of supporting structures of the rods, special attention is paid to the substantiation of its geometrical parameters in the longitudinal and transverse sections; studies of changes in the characteristics of vertical and horizontal vibrations, taking into account the method of the rod hanging and the system used for its stabilization. This allows to ensure the reliability of the rod design and the required quality of the technological process. The article proposes construction of the rod independent pendulum suspension on the sprayer frame and its stabilization system based on the use of damping elements. The analytical studies sequence system was developed for rod vibrations analysis, depending on initial conditions, parameters and characteristics of the used damping elements, under which they are effectively damped. It is shown that at certain numerical values of the geometrical parameters of the rod, the suspension and vibrations damping methods, not only the numerical values of the functions are changed, but also the functions themselves that describe the process of the rod's vertical movement, including cases of resonance. The obtained theoretical results can be used for design and testing of machines with rod working units and allow, at design stages, to simulate the process of movement of various rod structures from external excitatory forces, and to determine patterns of changes in the characteristics of damped vibrations using different damping elements and their installation parameters.

scholarly journals Boring a Discontinuous Surface: the Choice of Technological Modes

2019 ◽  
Vol 297 ◽  
pp. 01009
Author(s):  
Alexander Firsov ◽  
Alexander Qvcharenko ◽  
Alexander Romashev ◽  
Vitaly Smirnov ◽  
Aleksey Kamardin
Keyword(s):  
Technological Process ◽  
Design Stage ◽  
Technical Solution ◽  
Technical Documentation ◽  
Dynamic Effects ◽  
Discontinuous Surface ◽  
Quality Requirements ◽  
The Subject

The article deals with issues related to ensuring the quality of machining of a discontinuous surface. The subject of research is the technology of boring holes. Machining holes with intermittent areas on the surface is difficult due to the occurrence of dynamic effects. As a rule, regulatory and technical documentation does not give specific recommendations for such cases. The authors of the article describe the introduction of additional conditions, which allow determining the modes of boring holes with intermittent areas on the surface at the design stage of the technological process. This solution ensures that the part meets the specified quality requirements and allows you to verify the correctness of the technological decisions. The algorithm for selecting boring modes of holes with discontinuous surfaces implements the proposed technical solution in practice.

CONTROL IN REAL TIME THE DENSITY OF PRODUCT AT VARIOUS STAGES OF THE TECHNOLOGICAL PROCESS OF SUGAR PRODUCTION

2020 ◽  
Author(s):  
S.B. Kudryashev ◽  
◽  
N.S. Assev ◽  
R.D. Belashov ◽  
V.A. Naumenko ◽  
...  
Keyword(s):  
Real Time ◽  
Technological Process ◽  
Sugar Industry ◽  
Sugar Production ◽  
Production Processes ◽  
Quality Of Products

The article is devoted to solving one of the most important problems of the development of the sugar industry in Russia – the modernization of sugar production processes. Today, sugar production is actively being modernized, shifting most of its processes to the path of avomatization and optimization to improve the quality of products. This article describes one of the main ways to obtain information about the concentration of sucrose in syrup in the production of sugar.

MODIFYING THE TECHNOLOGICAL PROCESS OF A HAULM TOPPER TO IMPROVE THE QUALITY OF TABLE POTATO

2018 ◽  
pp. 7-12
Author(s):  
АNDREI B. KALININ ◽  
◽  
IGOR Z. TEPLINSKY ◽  
ОLEG V. SMELIK ◽  
ALEKSANDRA А. MANOKHINA ◽  
...  
Keyword(s):  
Technological Process

A Comprehensive Computational Study on OCH+-Rg (Rg = He, Ne, Ar, Kr, Xe) Complexes

2003 ◽  
Vol 68 (3) ◽  
pp. 489-508 ◽  
Author(s):  
Yinghong Sheng ◽  
Jerzy Leszczynski
Keyword(s):  
Computational Study ◽  
Relativistic Effects ◽  
Dft Method ◽  
Basis Set ◽  
Rare Gas ◽  
Geometrical Parameters ◽  
Minor Effect ◽  
Dissociation Energies ◽  
Equilibrium Geometries

The equilibrium geometries, harmonic vibrational frenquencies, and the dissociation energies of the OCH+-Rg (Rg = He, Ne, Ar, Kr, and Xe) complexes were calculated at the DFT, MP2, MP4, CCSD, and CCSD(T) levels of theory. In the lighter OCH+-Rg (Rg = He, Ne, Ar) rare gas complexes, the DFT and MP4 methods tend to produce longer Rg-H+ distance than the CCSD(T) level value, and the CCSD-calculated Rg-H+ bond lengths are slightly shorter. DFT method is not reliable to study weak interaction in the OCH+-He and OCH+-Ne complexes. A qualitative result can be obtained for OCH+-Ar complex by using the DFT method; however, a higher-level method using a larger basis set is required for the quantitative predictions. For heavier atom (Kr, Xe)-containing complexes, only the CCSD method predicted longer Rg-H+ distance than that obtained at the CCSD(T) level. The DFT method can be applied to obtain the semiquantitative results. The relativistic effects are expected to have minor effect on the geometrical parameters, the H+-C stretching mode, and the dissociation energy. However, the dissociation energies are sensitive to the quality of the basis set. The nature of interaction between the OCH+ ion and Rg atoms was also analyzed in terms of the interaction energy components.

scholarly journals A Rational Numerical Method for Simulation of Drop-Impact Dynamics of Oleo-Pneumatic Landing Gear

2021 ◽  
Vol 11 (9) ◽  
pp. 4136
Author(s):  
Rosario Pecora
Keyword(s):  
Numerical Method ◽  
Initial Conditions ◽  
Impact Load ◽  
Numerical Models ◽  
Landing Gear ◽  
Design Stage ◽  
Impact Dynamics ◽  
State Variables ◽  
Adopted Model ◽  
The Impact

Oleo-pneumatic landing gear is a complex mechanical system conceived to efficiently absorb and dissipate an aircraft’s kinetic energy at touchdown, thus reducing the impact load and acceleration transmitted to the airframe. Due to its significant influence on ground loads, this system is generally designed in parallel with the main structural components of the aircraft, such as the fuselage and wings. Robust numerical models for simulating landing gear impact dynamics are essential from the preliminary design stage in order to properly assess aircraft configuration and structural arrangements. Finite element (FE) analysis is a viable solution for supporting the design. However, regarding the oleo-pneumatic struts, FE-based simulation may become unpractical, since detailed models are required to obtain reliable results. Moreover, FE models could not be very versatile for accommodating the many design updates that usually occur at the beginning of the landing gear project or during the layout optimization process. In this work, a numerical method for simulating oleo-pneumatic landing gear drop dynamics is presented. To effectively support both the preliminary and advanced design of landing gear units, the proposed simulation approach rationally balances the level of sophistication of the adopted model with the need for accurate results. Although based on a formulation assuming only four state variables for the description of landing gear dynamics, the approach successfully accounts for all the relevant forces that arise during the drop and their influence on landing gear motion. A set of intercommunicating routines was implemented in MATLAB® environment to integrate the dynamic impact equations, starting from user-defined initial conditions and general parameters related to the geometric and structural configuration of the landing gear. The tool was then used to simulate a drop test of a reference landing gear, and the obtained results were successfully validated against available experimental data.

High-Speed Imaging to Study an Auto-Oscillating Vocal Fold Replica for Different Initial Conditions

2017 ◽  
Vol 09 (05) ◽  
pp. 1750064 ◽  
Author(s):  
A. Van Hirtum ◽  
X. Pelorson
Keyword(s):  
Vocal Fold ◽  
High Speed ◽  
Initial Conditions ◽  
Vocal Folds ◽  
High Speed Imaging ◽  
Human Voice ◽  
Manual Intervention ◽  
Geometrical Features ◽  
Upstream Pressure

Experiments on mechanical deformable vocal folds replicas are important in physical studies of human voice production to understand the underlying fluid–structure interaction. At current date, most experiments are performed for constant initial conditions with respect to structural as well as geometrical features. Varying those conditions requires manual intervention, which might affect reproducibility and hence the quality of experimental results. In this work, a setup is described which allows setting elastic and geometrical initial conditions in an automated way for a deformable vocal fold replica. High-speed imaging is integrated in the setup in order to decorrelate elastic and geometrical features. This way, reproducible, accurate and systematic measurements can be performed for prescribed initial conditions of glottal area, mean upstream pressure and vocal fold elasticity. Moreover, quantification of geometrical features during auto-oscillation is shown to contribute to the experimental characterization and understanding.

scholarly journals A Simulation Model of Construction Projects Executed in Random Conditions with the Overlapping Construction Works

2021 ◽  
Vol 13 (11) ◽  
pp. 5795
Author(s):  
Sławomir Biruk ◽  
Łukasz Rzepecki
Keyword(s):  
Simulation Model ◽  
Technological Process ◽  
Construction Projects ◽  
Working Time ◽  
Simulation Studies ◽  
Construction Methods ◽  
The Impact ◽  
Construction Works

Reducing the duration of construction works requires additional organizational measures, such as selecting construction methods that assure a shorter realization time, engaging additional resources, working overtime, or allowing construction works to be performed simultaneously in the same working units. The simultaneous work of crews may affect the quality of works and the efficiency of construction processes. This article presents a simulation model aimed at assessing the impact of the overlap period on the extension of the working time of the crews and the reduction of a repetitive project’s duration in random conditions. The purpose of simulation studies is to provide construction managers with guidelines when deciding on the dates of starting the sequential technological process lines realized by specialized working crews, for sustainable scheduling and organization of construction projects.

scholarly journals A New Approach to Assess the Quality of Small High-Speed Centrifugal Fans Using Noise Measurement

1999 ◽  
Vol 5 (2) ◽  
pp. 147-153 ◽  
Author(s):  
Dingjun Cui ◽  
Ian A. Craighead
Keyword(s):  
Signal Processing ◽  
Quality Assessment ◽  
Condition Monitoring ◽  
High Speed ◽  
Noise Levels ◽  
New Approach ◽  
Commercial Market ◽  
Centrifugal Fans ◽  
Special Approach

The requirements for a special approach for the quality assessment of small high-speed centrifugal fans are outlined and a new parameter designating the noise levels from the product in comprehensive form will be discussed and described as a criterion for such quality assessment.By applying techniques of signal processing and condition monitoring, the sources of the vibration and noise in different sections of the product can be identified, then the noise from each source from different components can be determined. Using this criterion, more aspects of the quality of the products can be assessed and suggestions to improve the quality of the products can be made. Finally, the assessment of a number ofvacuum cleaner motor/fan units available in the commercial market will be presented and compared with conventional specifications. It will be shown that the new parameter provides a more useful indication of appliance quality.

Structure of InAs Quantum Dots in Si Matrix Investigated by High Resolution Electron Microscopy

1999 ◽  
Vol 571 ◽  
Author(s):  
N. D. Zakharov ◽  
P. Werner ◽  
V. M. Ustinov ◽  
A.R. Kovsh ◽  
G. E. Cirlin ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Critical Thickness ◽  
High Resolution Electron Microscopy ◽  
Geometrical Parameters ◽  
Inas Quantum Dots ◽  
Temperature Growth ◽  
Transmission Electron ◽  
Resolution Electron

ABSTRACTQuantum dot structures containing 2 and 7 layers of small coherent InAs clusters embedded into a Si single crystal matrix were grown by MBE. The structure of these clusters was investigated by high resolution transmission electron microscopy. The crystallographic quality of the structure severely depends on the substrate temperature, growth sequence, and the geometrical parameters of the sample. The investigation demonstrates that Si can incorporate a limited volume of InAs in a form of small coherent clusters about 3 nm in diameter. If the deposited InAs layer exceeds a critical thickness, large dislocated InAs precipitates are formed during Si overgrowth accumulating the excess of InAs.

scholarly journals ESTIMATION OF STRUCTURAL SIMILARITY FOR CONTROL OF MICROELECTRONIC PRODUCTS

2019 ◽  
Vol 1 (7) ◽  
pp. 14-18
Author(s):  
Yu. A. Gusman ◽  
Yu. A. Pichugin ◽  
A. O. Smirnov
Keyword(s):  
Production Process ◽  
Technological Process ◽  
Good Reason ◽  
Structural Similarity ◽  
Fixed Number ◽  
Crystal Plate ◽  
Technological Scheme ◽  
Real Sample ◽  
Numerical Example

In this paper we consider the technological process of manufacturing micromechanical gyroscopes, the output of which is divided into cells of the crystal plate and each cell contains a fixed number of product elements. The estimation of structural similarity for measurements of technical characteristics of various devices is offered. A relatively large value of structural similarity assessment means that there is a dependence of the quality of the manufactured devices on the position on the crystal plate. This gives a good reason for further work to improve the quality of the process or to change the technological scheme as a whole. The article considers a numerical example based on a real sample of microelectronic products. The proposed method can be used both in the process of adjustment of the production process and in the rejection of products, when further configuration of the equipment is no longer possible.

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