The Main Objectives and Fields of Research of the Doctoral School



The majority of man-made goods are realized with the application of machines as well as with the help of machine tools. We could also say that without engineering mankind would never have reached its current level. However, the modernization of tools necessary for the improvement of living standards requires the solution of a number of engineering problems. Mechanical engineering works on a rather wide scale: it creates objects, technologies, manufacturing systems, controls their quality and safe operation, and concentrates significant efforts and assets on research and development. 

The educational and research programme of the Doctoral School encompasses three large areas. One deals with basic engineering sciences, the second with designing objects (machines and machine elements) and the third one is related to the issues of material sciences and materials processing technologies, as well as to production processes and production systems. 

As for engineering activity, it can be generally stated that the progress in computer technology, information science and its devices and - among others - the performance of computers, together with the development of the theory of material science and continuum mechanics, have recently been providing great opportunities for the complex modelling of physical phenomena, as well as for their reliable application, graphic visualisation and the versatile analysis of results. Complicated theories have become ordinary applied means of engineering practice after a thorough evaluation of the findings. These models can partly be used for design and production, and partly for the analyis of problems occuring during operation. Therefore it is justified on the basis of several aspects that the modelling of mechanical engineering problems plays a significant role in the work of the doctoral school. 

A mechanical model is generally studied from two main aspects. One aspect is the kinematic and dynamic analysis related to functional analysis, the other one is the determination of the state of deformation and stress. The analysis of the effect of operational parameters supplements the functional analysis: the machine construction study of wear, noise, friction losses, and so on provides guidelines for the modification of construction and technology. Decisions on different possibilities for damage and the possibilities of implementation of forming and manufacturing technology can be made by knowing the state of stress, taking the findings of material science into consideration. Naturally, the suitability and relevance of the model can be justified only by experiments and operating experience, which can also draw attention to the necessity for improvement.

The benefits of the computerization of analysis are found, in particular, in the case of nonlinear problems leading to nonlinear equations. It is known that material and geometrical nonlinearities should be distinguished. From the material aspect of models, a significant part of engineering can be described with the help of elastic material model. Geometrically linear problems (concerning machine tools, material handling systems, vehicles, thermal and hydrodynamic machine parts, different machine components, certain questions of fracture mechanics, etc.), as well as geometrically nonlinear problems occur when questions such as elastic elements, rubber composites, sheets, shells, contact problems or stability questions are discussed. 

Recent research is paying ever more attention to the analysis of questions of material science and forming technology, e.g. cutting, welding, metal forming (rolling, injection molding, forging, deep-drawing, cutting), and fractures, taking geometrical and material nonlinearity into consideration. Solving these tasks also provides the opportunity to analyse the effects of friction and heat transfer between bodies. 

The other class of nonlinear problems occur in the case of fluid and gas flow, taking into consideration viscosity and the strain of the flowing medium in the machine. It is impossible to list all the research topics and tasks. The following section presents only a small proportion of the topics researched within the doctoral school.

Main Research Fields 

  1. The structure of models giving proper description of real relationships
    Using computer-aided methods, the nonlinear effects of physical phenomena can also be considered. Nonlinear material properties changing with time, surface roughness (tribological problems), the wear of bodies sliding on each other, heat generation, electric and magnetic effects, different technological processes (welding, metal forming, machining), clarification of the behaviour of solid bodies (containers, pipelines) containing gas or fluid with a load changing over time - all of these mean a challenge which should be solved with experimental evidence, by setting up well-established phenomenological models and giving a reliable solution by use of the models. 
  2. Research of solution methods
    Although the speed of computers increases day by day, achieving the proper accuracy, particularly in case of nonlinear problems, pushes to the front the foundation of new variation methods in the field of finite element method, the adaptive regulation and regeneration of the mesh, as well as the development of parallel techniques for multiprocessor calculations. 
  3. Tasks related to coupled physical phenomena 
    One of the major groups of tasks involving body contact includes surface microgeometry, friction anisotropy, and heat generation caused by friction, as well as monitoring wear when the nonlinearly connected differential equation system related to thermal and mechanical fields has to be solved quickly, but with reasonable accuracy. 
    The other group of tasks is related to adaptive structures and mechatronic building elements. Complex mechanical systems require a reaction to adverse environmental effects. The application of the finite element method provides a good opportunity to analyse adaptive structures.
    The third group of tasks is in connection with the forecast of damage. Reliable (experimentally established) criteria are needed to forecast the development and spread of cracking and damage, while an accurate approximation of stress distribution is needed. Another group of tasks tries to clarify thermal processes of a strongly nonlinear character, occurring with transport processes, as well as the rheological relationships of fluids and gases and their mixtures with solid particles 
  4. Simulation, virtual production
    Models of mechanics describing reality are used, on the one hand, to determine stresses and strains and dynamic properties, on the other hand. From the stresses - on the basis of material science results - it is possible to deduce the long-term strength and lifespan, and we can also get information about the operation of the equipment.
    One of the ranges of simulation is related to making the material models more precise (e.g. in case of composites this relates to clarification of the relationship between the matrix and the strengthening fibres, and the definition of the residual stress arising in the course of production). The other range provides an opportunity to forecast the behaviour of the engineering equipment with different technological parameters (load, material properties, geometry, etc.). 
    In the case of forecasting, a crucial point is whether it is possible to examine the construction and the production technology before its introduction in a numerical way, without manufacturing the prototype. It is possible to accomplish virtual production, which is a fast and at the same time economical solution: this enables us to clarify the effect of certain parameters, and map optimum solutions with numerical experiments. The importance of this is increasingly significant in tough market competition. 
  5. Multidisciplinary optimization
    The development of the optimal design of structures and machines creates problems that need input from several disciplines, previously working independently of each other, and requiring the balance of the priorities of each discipline. An example is designing structures and technologies taking environmental protection into consideration. 
  6. 6. Mechatronic systems
    We are witnessing a new view of machine design, since a great number of machines and devices operate on electronic or other types of energy requiring control. Due to this the principles and methods of mechanics, informatics, electronics, control technology should be used jointly within a large system. In fact, the kinematic and dynamic properties of actual structures and devices can be identified by considering all interactions. More developed models of the operation of high-speed robots and mechanisms take into account even the deformation of elements.



Education and Research Programmes 

 Basic engineering sciences (Prof. I. Páczelt)  Mechanics of solids (Prof. Gy. Szeidl)
 Transport processes and machines (Prof. L. Baranyi)
 Design of machines and structures (Prof. G. Bognár)  Material handling machine design (Prof. B. Illés)
 Design of machines and elements (Prof. G. Bognár)
 Product Development and Design (Prof. G. Bognár)
 Design of mechatronic systems (Dr. T. Szabó)
 Design of engineering structures (Prof. K. Jármai)
 Design of machine tools (Dr. Gy. Hegedűs)
 Energy and chemical engineering systems design (Prof. Z. Siménfalvi)

 Engineering material science, production systems and   processes

 (Prof. J. Kundrák)

 Materials engineering and mechanical technology (Prof. J. Lukács)
 Manufacturing systems and processes (Dr. Zs. Maros)
 Assembly systems (Prof. Gy. Kovács)
 Structural integrity (Prof. J. Lukács)



1. Education and research programme related to the field of basic engineering sciences 
(leader: Prof. Dr. István Páczelt, HAS regular member)



Mechanics and thermodynamics are independently developing scientific fields of physics in the interest of engineering applications, which provide the opportunity to set up models more accurately describing real relationships occurring in engineering practice and giving solution with the help of mathematical knowledge. During the course students obtain deeper knowledge in the scientific fields of mechanics, thermodynamics and machines of solids and fluids, finite-degree-of-freedom systems and mechanics of mixtures. Modelling problems researched are of several kinds. Students can analyse solids, fluids or their complex systems and study connected systems in a wider sense (containing thermal, electric, magnetic and mechanical fields). A significant part of the research deals with establishing variational principles and methods based on the approximate solution of initial and boundary value problems. Research for increasing the accuracy of solutions and analysing the reffectiveness of numerical model is carried out and numerical experiments are also performed.
We should emphasize the importance of research in nonlinear problems that cover structural components, manufacturing processes, as well as heat and mass transfer processes. It is very important to define optimization problems carefully, to work out effective algorithms and to analyse the effects of feasibility criteria.
It is obvious that the application of computers is necessary to solve complicated initial and boundary value problems for the simulation of phenomena. An appropriate level of computer and programming knowledge and the ability of creating algorithms help applicants with their research. Working out suitable mechanical models requires proper measuring results, in some cases from carrying out experiments. Research can be divided into two major topic groups within the basic engineering sciences.

Topic groups



 

2. Education and research programme related to the topic field of design of machines and structures
(leader: Prof. Dr. Gabriella Vadászné Bognár, Professor)



During the course students get acquainted with machines in the broadest sense (hydraulic, pneumatic, electric, electronical, intelligent, etc.) and with the developing principles of their components, as well as the optimal solutions to technical problems. The course enables students to find the operating principles that are most suitable to achieve an objective, widening the scope of their usage in all fields of machine design, with the help of an interdisciplinary approach. The research also covers the analysis of models based on measurement and experimental studies, the application of simulation and animation methods, as well as optimization processes, dynamic and stochastic effects, asymmetries, production and assembly faults, effects of wear, the analysis of these effects, considering properties of moving goods, etc. 
The field of mechatronics integrates engineering, electrotechnical and electronic, automation and IT systems. In relation to machine tools, students get to know the most up-to-date production machines, tool machine designing trends, and during their work they combine engineering knowledge with the most up-to-date IT devices. 
The application of computer methods, CAD techniques, simulation methods and finite element method is typical of all fields. Ongoing research topics are systematic machine design and different versions of this discipline, as well as innovative technologies. 

Topic groups

 



 

3. Education and research programme related to the topic field of engineering material science, production systems and processes
(leader: Prof. Dr. János Kundrák, Professor Emeritus)



This education and research programme represents an independent academic field covering a wide spectrum of applied engineering sciences, which involves the most diverse fields of manufacturing processes and production technologies, from basic material sciences through pre-production processes to machine component manufacturing, and ensuring the operating conditions for engineering structures. The objective is the implementation of a scientific retraining course based on the university degree. Those participating in the course acquire the most important skills for designing and developing production processes and systems based on an up-to-date basic knowledge of mathematics, mechanics and material sciences. They master the application and development of modern computerized engineering methods and implementation of the computer-integrated production in practice. Students can manage the operating conditions and lifespan of engineering structures and machines using up-to-date technical and material analysing equipment for measurement and calculation. The participants obtain application-level proficiency in analysing engineering methods and damage in structural materials in the field of diagnosing the structural condition. 

Considering special features of the institution, education and research can be arranged into the following topic groups

All of the above-mentioned topic groups, significant features are the elaboration and theoretical analysis of models describing technological processes as perfectly as possible, the design of processes and production systems with up-to-date methods, and the creative application and development of computer-aided engineering methods. 

Application procedure and fees