Elaboration of Mathematical Models and Calculation Methods of Estimation of Resource Characteristics of Electromechanical Collector Converters

Author(s):  
O.S. Kachin
Author(s):  
V. M. Trukhanov ◽  
S. S. Basova ◽  
G. V. Trukhanov ◽  
G. I. Kuprovskiy

The issues of nomenclature choice of reliability indices and methods of reliability distribution between components of product have been considered in the present article. Calculation methods of design reliability of expensive nondiscarding objects like movable mountings and also mathematical models of design reliability, which taking into account random and nonrandom failures. The technique of calculation and achievement of required level reliability has been represented.


2021 ◽  
Vol 5 (2) ◽  
pp. 153-164
Author(s):  
Andrii Rudenko ◽  
Vladyslav Zubko ◽  
Viacheslav Khvorost ◽  
Andrii Lysenko

The object of study is a single-stage double-suction axially split volute casing centrifugal pump. Background. In the design process of pumps, the problems associated with ensuring the tightness of the axial joint of a pump casing being under the effect of mechanical and temperature loads, are being solved. During the study of axial joint tightness, numerical calculation methods are used to estimate the pressure intensity on the contacting surfaces. A detachable joint under the external load satisfies the criterions of the tightness if the pressure intensity on the sealing surfaces is higher than values of the specific pressure prescribed by regulations. However, inability to experimentally determine the pressure intensity on the contacting surfaces has so far prevented to assess the accuracy of results obtained by the numerical calculation methods. Objective. In order to verify the numerical results obtained by mathematical models, an experiment was carried out using a special Prescale film that registers the magnitude of the contact pressure on the joint of the specimen model of the flange fragment. Based on the experimental results, an analysis of the pressure intensity distribution was conducted. Methods. To conduct the experiment, there was developed a method for determining the pressure intensity on the contacting surfaces according to the proposed scheme of the specimen of the flange fragment. Results. A comparative analysis of the solving results obtained for the contact problem on the finite-element models of the flange fragment and the zone of the pump casing joint in the discharge chamber area showed a good coincidence of the results. Analysis of results obtained experimentally on the specimen of flange fragment and results of the numerical calculation on the flange fragment model also showed a good agreement. Conclusions. Therefore, results of the calculation of the pressure intensity in the detachable joints on mathematical models have been experimentally confirmed.


2019 ◽  
Vol 109 (05) ◽  
pp. 370-376
Author(s):  
S. Ihlenfeldt ◽  
J. Müller ◽  
D. Staroszyk

Die Berechnung der Lebensdauer von Profilschienenführungen (PSF) ist bei der Anlagenauslegung ein wesentlicher Bestandteil. Bei der wälzkontaktbezogenen Lebensdauerrechnung (WKBL) wird die Überlebenswahrscheinlichkeit jedes Wälzkontaktes berücksichtigt, was bei bestimmten Anordnungen von PSF, unter Momentenbelastung, bis zu 4-fach höhere Lebensdauerwerte als eine konventionelle Berechnung liefert. Neue mathematische Modelle erlauben eine adaptierbare und anwenderfreundliche Berechnung der WKBL.   Calculating the life span of profile rail guides is an essential part in designing new mechanical systems. The ‚rolling contact related life calculation‘ (RCRL) takes into account the survival probability of each rolling contact. This allows for calculating life spans up to four times higher than by conventional calculation methods for pitch and yaw moments on single profile rail guides. New mathematical models enable an adaptable and user-friendly calculation of RCRL.


Author(s):  
V. M. Trukhanov ◽  
S. S. Basova ◽  
G. V. Trukhanov ◽  
G. I. Kuprovskiy

The issues of nomenclature choice of reliability indices and methods of reliability distribution between components of product have been considered in the present article. Calculation methods of design reliability of expensive nondiscarding objects like movable mountings and also mathematical models of design reliability, which taking into account random and nonrandom failures. The technique of calculation and achievement of required level reliability has been represented.


2019 ◽  
Vol 49 (1) ◽  
pp. 47-68
Author(s):  
Waldemar Mironiuk

Abstract The article presents a modern method of modeling stability and unsinkability of vessels using physical models of warships and merchant ships. Model tests of watercraft are carried out primarily to assess their marine properties in various operational states. The purpose of this research is to create technically useful calculation methods for forecasting the behavior of a vessel at sea in various meteorological conditions. The main role played by model tests and measurements on real objects is the verification of these methods. Both types of experiments are also a source of inspiration for creating new modified mathematical models and accounting methods based on them. These tests can contribute to the improvement of the safety of vessels at sea.


Author(s):  
Aleksandr S. Kazachenko ◽  
Natalya Yu. Vasilyeva ◽  
Irina G. Sudakova ◽  
Vladimir A. Levdansky ◽  
Maxim A. Lutoshkin ◽  
...  

The process of abies ethanol lignin sulfation with sulfamic acid in 1,4-dioxane medium in the presence of urea was optimized by calculation methods. The influence of such factors, as the ratio of lignin/sulfating complex (L/SC), temperature and time of the sulfation process on the sulfur content in the resulting sulfated ethanol lignin and its yield, has been established. The variance analysis of the obtained mathematical models testifies their good predictive properties. The optimal conditions of abies ethanol lignin sulfation process, which provide the formation of water-soluble sulfated lignin with a high yield (to 100 % wt.) and sulfur content (up to 7.9 % wt.), have been established. They are: temperature of 95-100 °C, the ratio L/SC 1:2,3-1:2:9 and the time of the process 119-137 minutes


Author(s):  
V. M. Trukhanov ◽  
S. S. Basova ◽  
G. V. Trukhanov ◽  
G. I. Kuprovskiy

The issues of nomenclature choice of reliability indices and methods of reliability distribution between components of product have been considered in the present article. Calculation methods of design reliability of expensive nondiscarding objects like movable mountings and also mathematical models of design reliability, which taking into account random and nonrandom failures. The technique of calculation and achievement of required level reliability has been represented.


Vestnik MGSU ◽  
2019 ◽  
pp. 1280-1291
Author(s):  
Konstantin V. Kurguzov ◽  
Igor K. Fomenko

Introduction. Calculation and analysis of pile resistance to loads remains to be a relevant problem in geoengineering. The design of pile foundations is currently performed using diverse analytical, empirical and numerical methods. However, the reliability of these methods remains to be a topic of interest among researchers and designers. This research paper analyses methods used for calculating the lateral-load capacity of piles in comparison with field-test data. Materials and methods. The paper dwells upon the development of reliable analytical expressions based on mathematical models of the pile–soil interaction. Main existing mathematical models of the soil environment, including the Mohr – Coulomb elastic ideal plastic model and the hardening soil model (HSM) were analysed. A particular attention was paid to a variety of factors affecting the pile–soil interaction, such as natural factors, pile types, pile sinking depth and technology, configurations of loads, as well as time-changed processes. A comparison of methods for calculating the lateral-load capacity of piles was conducted. To that end, calculations using the Mohr – Coulomb model and the local elastic strain theory (still required by building codes) were performed. High-level solid elements were used to develop and compute a finite-element pile-in-soil model in a spatial setting. Another model on the basis of parametric pile elements was designed using the MIDAS software. Results. It is established that the use of numerical calculation methods for evaluating the capacity and movements of pile foundations provides results comparable to those of field tests. These methods demonstrate a higher reliability compared to standardized analytical techniques. Conclusions. The reliability of numerical calculations of pile resistance to lateral impact is shown to be sufficiently high, thus being feasible for use in geoengineering. The use of these methods should be based on advanced non-linear soil models, such as HS, CamClay, etc.


Author(s):  
V. M. Trukhanov ◽  
S. S. Basova ◽  
G. V. Trukhanov ◽  
G. I. Kuprovskiy

The issues of nomenclature choice of reliability indices and methods of reliability distribution between components of product have been considered in the present article. Calculation methods of design reliability of expensive nondiscarding objects like movable mountings and also mathematical models of design reliability, which taking into account random and nonrandom failures. The technique of calculation and achievement of required level reliability has been represented.


Sign in / Sign up

Export Citation Format

Share Document