N. Tontchev

Todor Kableshkov Higher School of Transport · Transport Manegment

ABSTRACT. The research presented in the book is devoted to numerical approaches to identification of effective solutions in the field of metallurgy and metalworking production. The approaches to obtain the optimal combination of chemical composition and heat treatment to achieve certain properties are fundamental for an effective project. They are...

Abstract: An algorithm for numerical analysis of multi-parametric regression models is introduced. It is intended for software realization mainly to offer an user-friendly environment for analysis, appropriate to/related to future multi-criteria optimization. The analysis is performed via visualizing various fragments from the domain supported by d...

The influence of chromium, molybdenum, tungsten, vanadium and silicon on the wear resistance and hardness after nitriding of heat-resistant steels ВН11 and ВН21 was examined. Additionally, the influence of alloying elements on the thickness of the bonded zone and the nitrided layer is considered. The analysis was performed through the process of mo...

The research adapted a five-factor problem with the DEFMOT computational approach [3] to a four-factor one using published experimental data [7] regarding the influence of coating component combinations on technological and mechanical performance. A methodology for the transformed adaptation from 5D to 4D has been compiled. The example of the effec...

The report discusses the possibilities of presenting graphical analysis related to a way of automated search for rational solutions. They are referred to the modern automotive industry. Cases of presentation with an odd and even number of factors are classified, and attention is focused on one, two, three and four factors. The analysis methods asso...

In this communication, the influence of the technological parameters on the surface properties of ВН11 steel depending on the conditions of ionic nitriding is examined. The complexity of the problem regarding the identification of the cited technological process lies in the fact that there are more than two technological parameters, and the examine...

The innovation with which more than 10 technologies have been solved is reduced to the use of a system supporting the making of technological decisions. Analysis of the mutual influence of a set of three, four or more control parameters is difficult, but a “counselor” developed as a system accounting for: 1. The exact complex interaction between th...

Goal of the Project: To generate 20 years of experience gained at the Transport University in decision-making in the field of technology and to present examples of good practice (benchmarking) in the application of a specialized (author's) approach. The approach has found application in the optimization of the dimensions of the construction of an a...

Surface texturing is one of the most effective approaches to modifying the surface to improve many properties: tribological, corrosion resistance, microhardness and others characteristics of a number of engineering materials. Among the surface texturing techniques developed in recent years, the most widely used method is the laser surface texturing...

The specific implementation determines the mode, so what we get as properties, and even more complicatedly as a complex of properties, is a consequence of what mode we set as a combination. The problem becomes extremely complicated when the number of parameters that form the mode increases. Each mode has a different impact on different quality indi...

Modern product design systems physically link CAD-CAE simulations into a single information model that must be optimized. In doing so, the logic between the mode of operation and the particularity of the construction, which in a certain sense determines the rational mode of operation, is always sought. In this video, an optimization approach will b...

DEFMOT-5D на конструктивни размери от характеристиките на флуиден анализ Съвременните системи за проектираните на изделия свързват физически CAD-САЕ симулациите в единен информационен модел, който е необходимо да бъде оптимизиран. При това винаги се търси логиката между режима на експлоатация и особеността на конструкцията, която в определен смисъл...

Selected documents related to the optimization of technological processes

A summary of the effectiveness of the most commonly used experimental designs for their use in CAD-CAE systems is made.

A methodology for optimization of technological parameters is described. The approach is universal. A specifically unique software has been developed on it. The approach is ready for demonstration.

Today we will return to a non-settling discipline successfully developed in the 1970s, because with the modern application of CAD-CAE systems in relation to simulation/computational experiments, it takes on a new importance. The discipline is Experiment Planning. The object of this representation as a sought-after and desired set of combinations of...

On the example of laser marking technology, we will consider the calculation approach: an approach applicable to all unestablished and unoptimized technological modes. My name is Nikolay Tonchev and I am a professor of modeling, analysis and optimization of technological processes. I am the author of a trademark registered in the patent office, the...

This research examines an approach for finding the optimal modes of laser treatment with CO2 laser on advertisement boards made of aluminium composite panels. To achieve the optimal area of the processing mode, an experimental methodology has been developed and an experiment has been planned for finding the limits at the given parameters of the s...

The pace of development of materials and technologies in recent years is growing with considerable speed. In it, the management of modern production processes is an analysis in which predetermined goals are achieved through the use of various resources – financial, material, energy, human factor and others. The optimal management and use of these r...

Ключови думи: Магнезиеви сплави, механични свойства, моделиране, оптимизация, материалознание, конвергенция. Резюме: Статията представлява обобщение на възможностите за анализ и оптимизация при изследвания на влиянието на химическия състав върху комплекса от свойства на различни сплави и композиции. За леснота на изложението са разгледани различни...

Ключови думи: йонно азотиране, оптимален режим, топлоустойчивост, ВН11, дебелина на свързаната зона при азотиране. Резюме: При изследването на азотираната стомана ВН11 е проведен планиран експеримент при който, една от изследваните величени е топлоустойчивасття на изследваните инструментални стомани. Този параметър е важен за експлоатационните каче...

Ключови думи: машинно инженерство, активно обучение, материалознание. Резюме: Изборът на материала е основен процес, във вземането на решение и той се основава на знания получени по дисциплините-материалознание, съпротивление на материалите, конструиране на машинни елементи, технология на машиностроителните материали и други технически дисциплини....

Ключови думи: проектиране състава на сплави, титанови сплави, якостни и пластични свойства. Резюме: В статията е представен подход и са утвърдени техники за определяне на компромисни решения при удовлетворяване на точно определени изисквания за свойствата на сплавите. За примерни конкретни свойства при изследвани титанови сплави се посочват възможн...

This generalized research is devoted to numerical approaches to identify effective solutions in the field of metallurgy. Approaches to obtain the optimal combination of chemical composition and heat treatment to achieve certain properties are of fundamental importance for the realization of an effective project. They are at the basis to design or i...

Ключови думи: Моделиране на свойства, Парето фронт, Многокритериална оптимизация, Магнезиеви сплави. Резюме: По предварително определени експериментирани състави, извън използваната за апроксимация база от данни, се определя апроксимация, най-точно отговаряща на определените условия. Апроксимацията се извършва посредством невронни модели. Подходът...

Ключови думи: шлифоване, технологични параметри, режим на шлифоване, моделиране оптимизация. Резюме: В статията е разглежда процес на шлифоване при изследване на два абразивни материала, чрез методите на моделиране и оптимизация. Анализът е установил чрез сравнение, че и двата абразива при два еднакви технологични фактора (размер на зърното и компр...

Пенобетонът е бетон, който има пореста структура, произведен от втвърдяване на разтвор, състоящ се от цимент, пясък, вода и пяна. Този материал се използва широко в строителството през последните години. Зимата в България е сравнително дълга, с продължителност от ноември до март и температурите падат под нулата. При бетоновите работи, ниските темпе...

Съдържание 1. Методи и инструменти, развиващи управлението на процесите чрез експериментална идентификация…………………………………………………… 1.1. Традиционна съвременна система………………………………………………….. 1.2. Независимо развитие на технологии на изкуствения интелект, свързани с анализа, управлението и оптимизацията…………………………………………… 1.3. Тенденции при съвместното...

Посочена е връзкаката между моделирането, анализа и оптимизацията на комплекса от свойства в материалознанието.

Определени са факторите на структурообразуването и влияние им върху основни свойства

Настоящото изследване има за цел да адаптира и приложи съществуваща идея при анализа и оптимизацията на производствения процес фрезуване, описан чрез събрана база от данни. Изследването допълва чрез еднокритериална и многокритериална оптимизация цитираният пример с нова неустановена полезна информация. Приносът на това изследване, е че по нов начин...

The present research summarises the influence of technological modes based on experimental studies of steels BH11 and BH21 (BS 4659) for hot work in ion nitriding. The peculiarity is that one or several precisely defined modes are not fixed, but a group of parameters from the action of the considered technology in a planned experiment is studied. A...

This research examines an approach for finding the optimal modes of laser treatment with CO2 laser on advertisement boards made of aluminium composite panels. To achieve the optimal area of the processing mode, an experimental methodology has been developed and an experiment has been planned for finding the limits at the given parameters of the spe...

The study recommends an approach for adequate prediction of the properties of high-strength austenitic steels with variation of the elements C, Si, Mn, Cr and Al by approximation with polynomials and second-order regression models. According to pre-set requirements, analysis and multicriteria optimization are performed, on the basis of which compos...

За факторите на структурообразуването и тяхното влияние върху основни свойства

ЗА РОЛЯТА НА МАТЕРИАЛОЗНАНИЕТО В ПРОЦЕСА НА ПРОЕКТИРАНЕ НА ТЕХНОЛОГИЧНИ РЕЖИМИ проф. НИКОЛАЙ ТОНЧЕВ http://tontchev.vtu.bg

As a rule, technological Statistical processing of experimental data and experiment planning as a method of optimization and research of technological processes are a powerful means of achieving the required results in the hands of the researcher. When carrying out experimental work, there is always a scatter in the obtained results. On this occasi...

Посочена е учебна презентация, обобщаваща дигиталния курс

Алгоритъм за логическо търсене с помощта ТРИЗ

Разглеждат се основни свойства на фибростъклото и оснавната схема на неговото получаване. Направени са определени изводи.

In modern scientific and engineering expertise there are a few methods for graphical computational analysis related to decision making. However, few of them are devoted to materials science and the determination of the complex of properties separately and simultaneously. This research proposes a decision analysis approach tested for the basic prope...

1. За трансфера на определени знания в областта на материалознанието. В науката и в инженерната практика съществува стремеж към унифициране, пренасяне и внедряване на идеи и знания от една област на човешкото познание в друга, подобна. При този трансфер е възможно да се използват по-пълноценно натрупан опит и работещи решения, чрез които се развив...

Decision support has also been shown to play an important role in the design process. The relevance of this activity is determined on the basis of the achieved benefits, as is the case with any other optimization process. Our development has been running for over fifteen years. Applied tasks in the field of casting, thermal and chemical-thermal tre...

In this review, a characteristic of the MADMML software methodology /approach is made. It has found an application for solving material science problems. In this area, it is necessary to define technological modes that correspond to a specific, most often contradictory complex of properties (several in number). Analyzing multiple technological mode...

Abstract. In modern scientific and engineering expertise there are a few methods for graphical computational analysis related to decision making. However, few of them are devoted to materials science and the determination of the complex of properties separately and simultaneously. This research proposes a decision analysis approach tested for the b...

This study aims to create a methodology for decision making in the process of designing the regime of the technological process of nitriding. The methodology is applied for relative degree of wear Kv for grade tool steels for hot working BH10, BH11 and BH21 and thus the stages of its implementation are demonstrated. They are used based on procedure...

Обобщена е работата с достъпен технологичен софтуер

Заключителна лекция по материалознание и неговата роля в машинното инженерство.

Приложен е подход за рацижнален избор

Преглед на методите

Управление на твърдостта след закаляване. Пример за управление на микроструктурен параметър в зависимост от леенето на джанти. Управление на свойствата на магнезиеви сплави за импланти.

In this review, a characteristic of the MADMML software methodology /approach is made. It has found an application for solving material science problems. In this area, it is necessary to define technological modes that correspond to a specific, most often contradictory complex of properties (several in number). Analyzing multiple technological mode...

Using computer simulation in the DEFORM-3D software package, we performed a virtual full factorial experiment for the ECAP-Conform processing of the low-alloyed chromium bronze Cu-0.14%Cr. In the course of the experiment we evaluated the effect of independent parameters (the rotation speed of the working wheel, the friction factor at the lateral su...

The paper presents the results of studies of tribological properties of the contact of the tool steel composition Fe-18W-4Cr-1,2V with the magnesium alloy AZ91D strengthened by submicron powder filling out of SiC and severe plastic deformation (SPD), namely equal-channel angular pressing (ECAP). It is stated that introduction of SiC powder filling...

My second dissertation was related to the optimization of the chemical composition of steels in the heat-treated state-hardening and high-temperature recovery. This research was published in Germany as my monograph. The theoretical explorations were investigations were confirmed in practice.  In this monograph, most of my modern computational meth...

Test of Materials Science

Резюме: Съобщението е свързано с двата основни подхода на проектирането /CAD-CAE анализите/, осигуряващи повишаване прага на служебните характеристики на елементи от авиационната техника, както и нейната икономичност. САЕ-изследванията се отнасят до моделиране на термо-и газодинамичните процеси, якостно-деформационното състояние на основни елементи...

ТРИЗ - MADMML

http://tontchev.vtu.bg

There are opportunities and competencies for the solution of the following two tasks with the participation of Nikolay Tonchev (described as a short version / I shall answer all Your additional questions). 1. Based on the provided alloy databases through a link between composition / (number and amount of alloying elements) and the investigated prop...

Research of Prof. Nikolay Tonchev Nikolay Tontchev-University of Transport, Sofia, tontchev@vtu.bg Summary: A survey of material science research, which includes studies on modeling and optimization of technological processes, welding of materials, technological tasks for the development of materials and their technologies, is made. The study is de...

A business plan description of a method developed as a service is used to help achieve certain benefits through an initial design in the laboratory. Optimization solutions are tested in practice, and then they can be deployed in production conditions if a certain economic effect is proven through calculations. An interested expert of the user / con...

For modeling, optimization and automated design of technological processes, as well as for the determination of the properties of the products under different conditions, software is required to perform the necessary calculations. The basis for these calculations can be experimental and stimulation / realizaed with CAE systems / research, generaliz...

Methtod with aplication in materials science http://tontchev.vtu.bg

Research Project 2020

This paper reports on the results of corrosion tests, using alternative methods, of Grade 4 CP Ti samples with coarse-grained (annealed) and ultrafine-grained structures after severe plastic deformation processing. The effect of microstructure on the corrosion of the material under study is demonstrated. It is revealed that the material with a UFG...

In this study, the stress state of metal coating on a steel substrate under tensile straining was investigated by with finite element modelling with the aim of better understanding the mechanism of delamination for the coating. The investigations showed cracking and delamination of the coating by the application of uniaxial tensile strain to the su...

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MCDM

For solving of the above described objectives the following scientific tasks have to be fulfilled: 1. Analysis of the contemporary state of all aspects of the project described above. This aim will be achieved via literature review, visiting of leading enterprises in order to adopt good practices, consulting with foreign and Bulgarian experts. 2. D...

Abstract. A review of the existing methods applied to multi-criteria decision aiding has been made as well as the multi-criteria approach to a class of problems in the field of material science has been defined. The multi-criteria decision aiding has been successfully applied to determine appropriate compromise decisions about the examined paramete...

Annotation: The paper presents the results of numerical modeling of the conventional drawing and free torsion processes of rods made of low-carbon steel using the "DEFORM-3D" software package. The heterogeneity of the strain intensity distribution in the investigated processes revealed in the model basically corresponds to real physical experiments...

The paper presents standard statistical procedures for determining expert assessments for the influence of magnesium alloy components on the controlled mechanical properties: tensile strength and relative elongation. There are obtained neural models describing mechanical characteristics from the amount of aluminum, manganese, nickel, iron and silic...

The achieved results give grounds for future active international cooperation with scientific and production institutions for which a specific scientific product has been created and tested. The elaborated scientific product is a set of numerical methods beyond the scope of the originally intended application only for metallurgical and metalworking...

The offer presented demonstrates the advantages and possibilities of a specialized software product for multi-criteria and multi-parameter aid with making decisions based on the method of movable limitations. This method has been considerably applied with developing a number of technology processes in the machine manufacturing production in order t...

The publication featured performance wear in a strike between standard weld test sample and realized if there is a layer of loose abrasive particles in the contact area. It gives an idea about the specifics of this type of wear, depending on the force of impact and size of the abrasive in different hardness achieved by welding of alloys with differ...

The article is dedicated to an approach optimizing a task of statistical modeling of the mechanical properties of products in real production metallurgy design. The approach is designed for the benefit of producers-metallurgists aimed at providing panels of Ti-alloys of a specific set of eventual industrial properties. This is accomplished by a pro...

KeyWords: Transport equipment, transport engineering, principles of Altshuller Abstract: Solving inventive tasks and finding new more rational decisions is a current task, which covers all areas of activity in modern life. The new and more correct solutions can be used both in the methodology of educational training and in our daily scientific and...

Shots of elements of design and technology aviation engine

Model of Strength and Reliability for Elements of Gas-Tyrbine Engine give conection between geometric configuration, model of material, model of loading and temperture state.

Model of Strength and Reliability for Elements of Gas-Tyrbine Engine give conection between geometric configuration, model of material, model of loading and temperture state.

Abstract: The paper presents the characteristics of a modern software system for modeling and optimization of technological processes MOTP_VTU. It outlines the possibilities also to use the system at the design stage. A comparative analysis is performed of three characteristics to apply the new software system MOTP_VTU related to a similar existing...

Application of diverent materials of various components of the turbine engine

The paper contains results for wear in conditions of impact between a standard welded and tested specimen realized in the presence of a layer of abrasive particles trailing in the contact zone. It gives an idea about the specifics of this type of wear depending on the impact force and the particle size of the abrasive at various hardness achieved b...

The report presents an approach for determining the influence of the technological casting parameters (temperature of the molten metal, the time between two casting cycles, and counter-pressure) on microstructural characteristic DAS. The study was carried out on six different sections of interest of the aluminum casting volume with regard to the pe...

MCDM in magnesium or titanium base alloys.

(2008), Modeling of problems of metal building – up by welding with multiple criteria, IIT/WP – 247, pp. 1 – 7.

This generalized research is devoted to numerical approaches to identify effective solutions in the field of metallurgy. Approaches to obtain the optimal combination of chemical composition and heat treatment to achieve certain properties are of fundamental importance for the realization of an effective project. They are at the basis to design or i...