2/2022
• 2/2022 table of contents
INVETIGATION OF TUMBLE RATIO IN TWO DIFFERENT ENGINE VALVE CONSTRUCTIONS
László Kovács, Dr. Szilárd Szabó, Dr. Betti Bolló 5
To underline the superior parameters of the newly designed valve system comparative numerical simulations were conducted in order to define the tumbling action inside the cylinder using poppet valve and Swinging Valve arrangements. Keeping the flow parameters identical results showed marked improvements in the tumbling action which is a prerequisite of successful employment of the extra lean working principle in stratified charging engines.
HEAT PUMP IN THE FUTURE
Gábor Hornyák, Péter Bozzay 11
Heat pump systems offer economical alternatives for recovering heat from a variety of sources for a range of industrial, commercial and residential applications. Improving the performance, reliability and environmental impact of heat pumps is an ongoing challenge for professionals. This article describes recent advances in heat pump systems, their implementation and application, and their potential and benefits.
OPTIMIZATION OF TRANSMISSION LINE TOWER WITH EVOLUTIONARY AND FEM TECHNICS
Nagy Szilárd, Dr. Károly Jármai, Dr. Attila Baksa 17
The optimization of the pylon is shown in this paper. The optimization is made by using flower pollination algorithm. The objective function is mass of the structure. The design constraints are static stress, local buckling and buckling. The unknowns are the typical dimensions of the circular hollow section truss. Parametric inspections have been made changing yield strength of material and the number of grid divisions. The results show that the use of higher yield strength steels, do not imply a lighter structure.
OPTIMAL DESIGN OF FRAME STRUCTURES FOR DIFFERENT LOADS
Dr. Máté Petrik, Dr. Károly Jármai 24
This paper deals with the optimal sizing of frame structures with rigid corner connections. The optimization has been carried out with different loads, but in comparable load ranges, where the optimization objective function is the minimum steel mass. The results show that for beams subjected to bending, higher strength steels, require smaller cross-sectional areas, but for beams subjected to compression, due to the phenomenon of buckling, the steel grades investigated require practically the same geometric dimensions.
THEORETICAL BACKGROUND OF THE COMPOSITE HELICOPTER FLOOR OPTIMISATION
Dr. Alaa Al-Fatlawi, Dr. Károly Jármai and Dr. György Kovács 30
The research objective was to design a novel optimization approach for a helicopter floor made entirely of FRP composite material. The optimization process involved examining 46 distinct layer combinations of four different FRP layers (woven glass fiber with phenolic resin; woven glass fiber with epoxy resin; woven carbon fiber with epoxy resin; hybrid composite) and four different FRP honeycomb core structural elements. The face sheets were constructed using a variety of different
layer counts and fiber orientations including cross-laminated, angled, and multidirectional.
EXAMPLE FOR THE OPTIMISATION OF COMPOSITE HELICOPTER FLOOR
Dr. Alaa Al-Fatlawi, Dr. Károly Jármai and Dr. György Kovács 38
The optimization procedure of a composite floor system has been shown. Nine design constraints have been considered: deflection; face stress (bending load, end load); stiffness; flexure; core shear stress; shell buckling; in-cell buckling; and shear buckling. The single-objective weight optimization problem was solved using Matlab’s Interior Point Technique, Excel Solver’s nonlinear Generalized Reduced Gradient (GRG) algorithm, and Laminator software. The numerical simulation of ideal sandwich plates was shown using the Digimat-HC program. The totally FRP composite sandwich structure optimization has been shown through a case study.
DEPENDENCE OF EIGENVALUES ON PARAMETER CHANGES OF OPTIMIZED STIFFENED PLATES
Dr. Zoltán Virág, Dr. Sándor Szirbik 43
This paper deals with the modal analysis and buckling stability of stiffened plates under longitudinal compression with simple supported conditions. The effect of stiffener damage caused by corrosion can be investigated in FE models of the optimized stiffed plate structure. The buckling shape modes for damaged structures can be compared with the damaged-free ones so that the changes in load capacity can be predicted. The eigenfrequencies show noticeable differences when the modulus of
elasticity is changed. Therefore, it is important that the structure is properly designed and made from proper materials.
TESTING A FERTILIZATION OPTIMIZATION ALGORITHM IN THE CEC2015 ENVIRONMENT AND APPLYING IT TO LARGE-SCALE PROBLEMS
Hazim Nasir Ghafil, Shaymaa Alsamia and Dr. Károly Jármai 47
This paper presents the fertilization optimization algorithm, a new optimization method based on Levy’s flight and random search in a search space. In CEC2015, the algorithm’s performance was compared to that of other optimization algorithms using time-consuming benchmarks and large-scale optimization problems. The fertilization optimization algorithm outperformed other optimization algorithms in many cases.
COLD FORMING PROBLEMS IN BULLET METAL JACKET DRAWING TECHNOLOGY
Leitold András 55
The design of a projectile manufacturing technology used on an assembly machine belonging to a unique projectile construction is presented. The projectile, the most important component of the cartridge, ultimately carries the energy that needs to be delivered as accurately as possible. Deep-drawing errors usually do not occur on their own but in a complex
way, so more errors need to be fixed to correct them.
VOC VALVE STEM SEALING TEST BENCH
Behofsits Antal 60
Szelence Ltd. won a research and development tender for the reduction of VOC (volatile organic compound) leakage through special seal testing. During the project, a test bench was developed, which can be used to examine the VOC leakage of the valve stems under parameters close to the real operating environment (medium, pressure, temperature). During the implementation of the research and development project, the completion of the final measuring bench was preceded by several prototypes.
INVETIGATION OF TUMBLE RATIO IN TWO DIFFERENT ENGINE VALVE CONSTRUCTIONS
László Kovács, Dr. Szilárd Szabó, Dr. Betti Bolló 5
To underline the superior parameters of the newly designed valve system comparative numerical simulations were conducted in order to define the tumbling action inside the cylinder using poppet valve and Swinging Valve arrangements. Keeping the flow parameters identical results showed marked improvements in the tumbling action which is a prerequisite of successful employment of the extra lean working principle in stratified charging engines.
HEAT PUMP IN THE FUTURE
Gábor Hornyák, Péter Bozzay 11
Heat pump systems offer economical alternatives for recovering heat from a variety of sources for a range of industrial, commercial and residential applications. Improving the performance, reliability and environmental impact of heat pumps is an ongoing challenge for professionals. This article describes recent advances in heat pump systems, their implementation and application, and their potential and benefits.
OPTIMIZATION OF TRANSMISSION LINE TOWER WITH EVOLUTIONARY AND FEM TECHNICS
Nagy Szilárd, Dr. Károly Jármai, Dr. Attila Baksa 17
The optimization of the pylon is shown in this paper. The optimization is made by using flower pollination algorithm. The objective function is mass of the structure. The design constraints are static stress, local buckling and buckling. The unknowns are the typical dimensions of the circular hollow section truss. Parametric inspections have been made changing yield strength of material and the number of grid divisions. The results show that the use of higher yield strength steels, do not imply a lighter structure.
OPTIMAL DESIGN OF FRAME STRUCTURES FOR DIFFERENT LOADS
Dr. Máté Petrik, Dr. Károly Jármai 24
This paper deals with the optimal sizing of frame structures with rigid corner connections. The optimization has been carried out with different loads, but in comparable load ranges, where the optimization objective function is the minimum steel mass. The results show that for beams subjected to bending, higher strength steels, require smaller cross-sectional areas, but for beams subjected to compression, due to the phenomenon of buckling, the steel grades investigated require practically the same geometric dimensions.
THEORETICAL BACKGROUND OF THE COMPOSITE HELICOPTER FLOOR OPTIMISATION
Dr. Alaa Al-Fatlawi, Dr. Károly Jármai and Dr. György Kovács 30
The research objective was to design a novel optimization approach for a helicopter floor made entirely of FRP composite material. The optimization process involved examining 46 distinct layer combinations of four different FRP layers (woven glass fiber with phenolic resin; woven glass fiber with epoxy resin; woven carbon fiber with epoxy resin; hybrid composite) and four different FRP honeycomb core structural elements. The face sheets were constructed using a variety of different
layer counts and fiber orientations including cross-laminated, angled, and multidirectional.
EXAMPLE FOR THE OPTIMISATION OF COMPOSITE HELICOPTER FLOOR
Dr. Alaa Al-Fatlawi, Dr. Károly Jármai and Dr. György Kovács 38
The optimization procedure of a composite floor system has been shown. Nine design constraints have been considered: deflection; face stress (bending load, end load); stiffness; flexure; core shear stress; shell buckling; in-cell buckling; and shear buckling. The single-objective weight optimization problem was solved using Matlab’s Interior Point Technique, Excel Solver’s nonlinear Generalized Reduced Gradient (GRG) algorithm, and Laminator software. The numerical simulation of ideal sandwich plates was shown using the Digimat-HC program. The totally FRP composite sandwich structure optimization has been shown through a case study.
DEPENDENCE OF EIGENVALUES ON PARAMETER CHANGES OF OPTIMIZED STIFFENED PLATES
Dr. Zoltán Virág, Dr. Sándor Szirbik 43
This paper deals with the modal analysis and buckling stability of stiffened plates under longitudinal compression with simple supported conditions. The effect of stiffener damage caused by corrosion can be investigated in FE models of the optimized stiffed plate structure. The buckling shape modes for damaged structures can be compared with the damaged-free ones so that the changes in load capacity can be predicted. The eigenfrequencies show noticeable differences when the modulus of
elasticity is changed. Therefore, it is important that the structure is properly designed and made from proper materials.
TESTING A FERTILIZATION OPTIMIZATION ALGORITHM IN THE CEC2015 ENVIRONMENT AND APPLYING IT TO LARGE-SCALE PROBLEMS
Hazim Nasir Ghafil, Shaymaa Alsamia and Dr. Károly Jármai 47
This paper presents the fertilization optimization algorithm, a new optimization method based on Levy’s flight and random search in a search space. In CEC2015, the algorithm’s performance was compared to that of other optimization algorithms using time-consuming benchmarks and large-scale optimization problems. The fertilization optimization algorithm outperformed other optimization algorithms in many cases.
COLD FORMING PROBLEMS IN BULLET METAL JACKET DRAWING TECHNOLOGY
Leitold András 55
The design of a projectile manufacturing technology used on an assembly machine belonging to a unique projectile construction is presented. The projectile, the most important component of the cartridge, ultimately carries the energy that needs to be delivered as accurately as possible. Deep-drawing errors usually do not occur on their own but in a complex
way, so more errors need to be fixed to correct them.
VOC VALVE STEM SEALING TEST BENCH
Behofsits Antal 60
Szelence Ltd. won a research and development tender for the reduction of VOC (volatile organic compound) leakage through special seal testing. During the project, a test bench was developed, which can be used to examine the VOC leakage of the valve stems under parameters close to the real operating environment (medium, pressure, temperature). During the implementation of the research and development project, the completion of the final measuring bench was preceded by several prototypes.
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