As it is known, the parameters of a commercial vehicle, and therefore the cardan shaft, are not k... more As it is known, the parameters of a commercial vehicle, and therefore the cardan shaft, are not known in the initial design phase. Therefore, in this paper, an attempt is made to define the necessary dimensions based on the minimization of torsional vibrations of the pipe, while simultaneously minimizing the mass and maximizing the polar moment of inertia of the cross-section. Attention is paid to the choice of the objective function in the optimization process, with a special focus on the interrelationship of sub-objectives. The author's previously developed model of the cardan shaft and stochastic parametric optimization based on the Hooke-Jeeves method was used for the research. The calculated values of the unknown parameters of the cardan shaft are intended to be used for the final selection of its standard dimensions in the later design phase.
10th International Conference „NEW TECHNOLOGIES, DEVELOPMENT AND APPLICATION“ NT-2024 June 20-22. 2024 Sarajevo, Bosnia and Herzegovina, 2024
Vibrations that occur during the operation of commercial motor vehicles lead to fatigue of the us... more Vibrations that occur during the operation of commercial motor vehicles lead to fatigue of the users and materials of the aggregates. Therefore, in this paper, an attempt was made to develop a method for their identification. The method is illustrated in the example of the axle spindle lever, and for the twovariable frequency analysis, the 2D Fourier transform was used. The illustration of the procedure's applicability was performed on its idealized model, and the conducted research showed that the two-parameter frequency analysis can also be used in generating transverse vibrations in laboratory conditions.
The conceptual design represents the concretization of project requirements defined based on mark... more The conceptual design represents the concretization of project requirements defined based on market data. This paper will focus on the steering system, specifically the steering arm. The parameters of the steering arm are not known in the initial design phase of a heavy motor vehicle, so an attempt is made here to define the necessary dimensions based on the minimization of its lateral vibrations, while simultaneously minimizing the mass and maximizing the critical buckling force. For this purpose, a simplified geometric, physical, and mathematical model of the steering arm, as well as the stochastic parameter optimization method and 2D Fourier transform, were used.
As it is known, the parameters of a heavy motor vehicle, including the frame, are not known in th... more As it is known, the parameters of a heavy motor vehicle, including the frame, are not known in the initial design phase of the vehicle. Therefore, in this paper, an attempt is made to define the necessary dimensions based on the minimization of its lateral vibrations, while simultaneously minimizing the mass and maximizing the moment of inertia of the cross-section of the frame. Attention is given to the choice of the objective function in the optimization process, with a special focus on the interrelation of sub-objectives. The author's previously developed frame model and "stochastic parametric optimization" based on the Hooke-Jeeves method were used for the research. The calculated value of the unknown frame parameter is intended to serve for the final selection of the frame structure in the later design phase.
CONTRIBUTION TO THE DEVELOPMENT OF A METHOD FOR
OPTIMAL DIMENSIONING OF THE STEERING ROD IN THE
C... more CONTRIBUTION TO THE DEVELOPMENT OF A METHOD FOR OPTIMAL DIMENSIONING OF THE STEERING ROD IN THE CONCEPTUAL DESIGN PHASE OF A COMMERCIAL MOTOR VEHICLE MIROSLAV DEMIĆ Faculty of Engineering Sciences (retired professor), Kragujevac, Serbia E. mail: demic@kg,ac.rs Abstract: The conceptual design represents the first concretization of the project task, and its main goal is to define the parameters of the driver's ergosphere and the external dimensions, mass, and performance of the commercial vehicle, as well as its stylistic indicators, necessary for further work on the project. As is known, the parameters of the steering rod are not known in the initial phase of designing a commercial vehicle, so in this paper, an attempt was made to define the necessary dimensions based on the minimization of its transversal vibrations, simultaneous minimization of mass, and maximization of the critical buckling force. For these purposes, a simplified geometric, physical, and mathematical model of the rod, the method of stochastic parametric optimization, and 2D Fourier transform were used. Keywords: Commercial vehicle, steering linkage, transverse vibrations, mass, critical
Suspension systems have great influence on vehicle characteristics especially ride comfort and ha... more Suspension systems have great influence on vehicle characteristics especially ride comfort and handling. Classical suspension systems may only offer a compromise among requirements for ride comfort and vehicle handling in a narrow range of service conditions. Better characteristics are provided by application of suspension systems with controlled characteristics: semi active and active systems. Active suspension systems introduce special force generators, power demanding, so as to obtain favorable characteristics. Their prices are fairly high, so that the application may take place in high vehicle class. Semi active suspension is based on control of spring characteristics, or, more often, damping characteristics, providing acceptable output characteristics for medium and high class vehicles. Therefore, this paper will mostly deal with the design of semi active suspension systems, based on control of damping parameters. A method of "stochastic parameters optimization" has been utilized for the optimization of parameters of semi active suspension. The optimization objective was a simultaneous minimization of sprung mass vibration and standard deviation of dynamic ground reactions.
The conceptual design represents the first concretization of the project task, and its main goal ... more The conceptual design represents the first concretization of the project task, and its main goal is to define the parameters of the driver's ergo-sphere, external dimensions, weight, and performance of the heavy motor vehicle, as well as its stylistic indicators, necessary for further work on the project. As is known, the parameters of the frame are not known in the initial phase of designing a heavy motor vehicle, so in this paper, an attempt was made to define the required torsional stiffness of the frame based on its transverse vibrations. For this purpose (with the introduced hypothesis), a simplified geometric, physical, and mathematical model of the frame was used, whose random transverse vibrations will be analyzed using some methods of mathematical statistics and the three-variable Fourier transformation.
During exploitation, motor vehicles are subjected to vibration loads that lead to fatigue of thei... more During exploitation, motor vehicles are subjected to vibration loads that lead to fatigue of their users and materials of their aggregates. Therefore, vibrations must be studied from the earliest stage of development, using mathematical models, experiments, or their combinations. In theoretical studies, vibrations of concentrated masses are usually observed, although, with the development of numerical methods (especially finite element method), attention is paid to vibrations of elastic vehicle systems. Then, idealizations are usually made, especially regarding operational conditions and relationships between motor vehicle aggregates. In this paper, an attempt was made to develop a method for identifying real vibration loads of elastic vehicle cardan shafts under operational conditions. Namely, 2D Fourier transformation was used for two-parameter frequency analysis. The possibility of the procedure's application was demonstrated on an idealized elastic cardan shaft. The research showed that two-parameter frequency analysis can be used to generate torsional vibrations of elastic vehicle cardan shafts in laboratory conditions.
During exploitation, commercial motor vehicles are exposed to various types of loads, among which... more During exploitation, commercial motor vehicles are exposed to various types of loads, among which vibrations are of particular importance. Vibrations lead to fatigue of vehicle users and materials of their components. Therefore, they must be studied in the earliest stages of design, using mathematical models, experiments, or their combinations. In theoretical considerations, vibrations of concentrated masses are usually observed, although recently, with the development of numerical methods (especially finite element methods), attention has also been paid to the vibrations of elastic systems of these vehicles. In such cases, simplifications are usually made, especially regarding exploitation conditions and interconnections of vehicle components. This paper attempts to develop a method for identifying vibrational loads on the controlling lever under exploitation conditions, using a two-parameter frequency analysis with the use of 2 D Fourier transform. The applicability of the procedu...
Journal of Mechanical Engineering and Modern Technology, 2018
Dynamic simulation, based on modelling, has a significant role during to the process of vehicle d... more Dynamic simulation, based on modelling, has a significant role during to the process of vehicle development. It is especially important in the first design stages, when relevant parameters are to be defined. Powertrain mounting system is exposed to thermal loads which can lead to its damage and degradation of characteristics. Therefore, this paper attempts to analyse a conversion of mechanical work into heat energy by use of a method of dynamic simulation. Bearing in mind the most frequent application of classic - mechanical and hydraulic powertrain suspension in modern trucks, this paper will present analyses of thermal load of a vehicle manufactured by the domestic manufacturer FAP. The issue of heat dissipation from the powertrain mounting system has not been taken into consideration. The experimental verification of the results will be done in next investigations.
During exploitation, motor vehicles are exposed to vibrational loads that cause fatigue for users... more During exploitation, motor vehicles are exposed to vibrational loads that cause fatigue for users and material fatigue of their components. Therefore, vibrations must be studied at the earliest stage of design, using mathematical models, experiments, or a combination of both. Generally, there are idealizations during theoretical analysis, particularly concerning operating conditions and the interrelationships of motor vehicle components. This paper attempts to develop a method for identifying actual loads in continuous vehicle systems in exploitation conditions, based on recorded spatial vibrations. Multi-parameter frequency analysis was used for 2D, 3D, and 4D Fourier transformations. An illustration of the application of these procedures was carried out on idealized continuous vehicle elements such as bars, membranes, and parallelepipeds.
Tracked vehicles are exposed to vibrational loads during exploitation, which leads to fatigue of ... more Tracked vehicles are exposed to vibrational loads during exploitation, which leads to fatigue of users and materials of their aggregates. Therefore, they must be studied even in the earliest stages of design, using mathematical models, experiments, or combinations. In theoretical considerations, vibrations of concentrated masses are usually observed, although, with the development of numerical methods (especially finite element methods), attention is paid to vibrations of elastic systems of tracked vehicles. Then, usually, idealizations are made, especially regarding operational conditions and mutual connections of vehicle aggregates...
This paper attempts to develop a method for identifying real vibrational loads of the track of a tracked vehicle in exploitation conditions, using 2D Fourier transform for two-parameter frequency analysis. The illustration of the possibilities of the procedure was performed on an idealized track of a tracked vehicle. The research conducted showed that two-parameter frequency analysis can also be used to generate transverse vibrations of the track in laboratory conditions.
As it is known, the parameters of a commercial vehicle, and therefore the cardan shaft, are not k... more As it is known, the parameters of a commercial vehicle, and therefore the cardan shaft, are not known in the initial design phase. Therefore, in this paper, an attempt is made to define the necessary dimensions based on the minimization of torsional vibrations of the pipe, while simultaneously minimizing the mass and maximizing the polar moment of inertia of the cross-section. Attention is paid to the choice of the objective function in the optimization process, with a special focus on the interrelationship of sub-objectives. The author's previously developed model of the cardan shaft and stochastic parametric optimization based on the Hooke-Jeeves method was used for the research. The calculated values of the unknown parameters of the cardan shaft are intended to be used for the final selection of its standard dimensions in the later design phase.
10th International Conference „NEW TECHNOLOGIES, DEVELOPMENT AND APPLICATION“ NT-2024 June 20-22. 2024 Sarajevo, Bosnia and Herzegovina, 2024
Vibrations that occur during the operation of commercial motor vehicles lead to fatigue of the us... more Vibrations that occur during the operation of commercial motor vehicles lead to fatigue of the users and materials of the aggregates. Therefore, in this paper, an attempt was made to develop a method for their identification. The method is illustrated in the example of the axle spindle lever, and for the twovariable frequency analysis, the 2D Fourier transform was used. The illustration of the procedure's applicability was performed on its idealized model, and the conducted research showed that the two-parameter frequency analysis can also be used in generating transverse vibrations in laboratory conditions.
The conceptual design represents the concretization of project requirements defined based on mark... more The conceptual design represents the concretization of project requirements defined based on market data. This paper will focus on the steering system, specifically the steering arm. The parameters of the steering arm are not known in the initial design phase of a heavy motor vehicle, so an attempt is made here to define the necessary dimensions based on the minimization of its lateral vibrations, while simultaneously minimizing the mass and maximizing the critical buckling force. For this purpose, a simplified geometric, physical, and mathematical model of the steering arm, as well as the stochastic parameter optimization method and 2D Fourier transform, were used.
As it is known, the parameters of a heavy motor vehicle, including the frame, are not known in th... more As it is known, the parameters of a heavy motor vehicle, including the frame, are not known in the initial design phase of the vehicle. Therefore, in this paper, an attempt is made to define the necessary dimensions based on the minimization of its lateral vibrations, while simultaneously minimizing the mass and maximizing the moment of inertia of the cross-section of the frame. Attention is given to the choice of the objective function in the optimization process, with a special focus on the interrelation of sub-objectives. The author's previously developed frame model and "stochastic parametric optimization" based on the Hooke-Jeeves method were used for the research. The calculated value of the unknown frame parameter is intended to serve for the final selection of the frame structure in the later design phase.
CONTRIBUTION TO THE DEVELOPMENT OF A METHOD FOR
OPTIMAL DIMENSIONING OF THE STEERING ROD IN THE
C... more CONTRIBUTION TO THE DEVELOPMENT OF A METHOD FOR OPTIMAL DIMENSIONING OF THE STEERING ROD IN THE CONCEPTUAL DESIGN PHASE OF A COMMERCIAL MOTOR VEHICLE MIROSLAV DEMIĆ Faculty of Engineering Sciences (retired professor), Kragujevac, Serbia E. mail: demic@kg,ac.rs Abstract: The conceptual design represents the first concretization of the project task, and its main goal is to define the parameters of the driver's ergosphere and the external dimensions, mass, and performance of the commercial vehicle, as well as its stylistic indicators, necessary for further work on the project. As is known, the parameters of the steering rod are not known in the initial phase of designing a commercial vehicle, so in this paper, an attempt was made to define the necessary dimensions based on the minimization of its transversal vibrations, simultaneous minimization of mass, and maximization of the critical buckling force. For these purposes, a simplified geometric, physical, and mathematical model of the rod, the method of stochastic parametric optimization, and 2D Fourier transform were used. Keywords: Commercial vehicle, steering linkage, transverse vibrations, mass, critical
Suspension systems have great influence on vehicle characteristics especially ride comfort and ha... more Suspension systems have great influence on vehicle characteristics especially ride comfort and handling. Classical suspension systems may only offer a compromise among requirements for ride comfort and vehicle handling in a narrow range of service conditions. Better characteristics are provided by application of suspension systems with controlled characteristics: semi active and active systems. Active suspension systems introduce special force generators, power demanding, so as to obtain favorable characteristics. Their prices are fairly high, so that the application may take place in high vehicle class. Semi active suspension is based on control of spring characteristics, or, more often, damping characteristics, providing acceptable output characteristics for medium and high class vehicles. Therefore, this paper will mostly deal with the design of semi active suspension systems, based on control of damping parameters. A method of "stochastic parameters optimization" has been utilized for the optimization of parameters of semi active suspension. The optimization objective was a simultaneous minimization of sprung mass vibration and standard deviation of dynamic ground reactions.
The conceptual design represents the first concretization of the project task, and its main goal ... more The conceptual design represents the first concretization of the project task, and its main goal is to define the parameters of the driver's ergo-sphere, external dimensions, weight, and performance of the heavy motor vehicle, as well as its stylistic indicators, necessary for further work on the project. As is known, the parameters of the frame are not known in the initial phase of designing a heavy motor vehicle, so in this paper, an attempt was made to define the required torsional stiffness of the frame based on its transverse vibrations. For this purpose (with the introduced hypothesis), a simplified geometric, physical, and mathematical model of the frame was used, whose random transverse vibrations will be analyzed using some methods of mathematical statistics and the three-variable Fourier transformation.
During exploitation, motor vehicles are subjected to vibration loads that lead to fatigue of thei... more During exploitation, motor vehicles are subjected to vibration loads that lead to fatigue of their users and materials of their aggregates. Therefore, vibrations must be studied from the earliest stage of development, using mathematical models, experiments, or their combinations. In theoretical studies, vibrations of concentrated masses are usually observed, although, with the development of numerical methods (especially finite element method), attention is paid to vibrations of elastic vehicle systems. Then, idealizations are usually made, especially regarding operational conditions and relationships between motor vehicle aggregates. In this paper, an attempt was made to develop a method for identifying real vibration loads of elastic vehicle cardan shafts under operational conditions. Namely, 2D Fourier transformation was used for two-parameter frequency analysis. The possibility of the procedure's application was demonstrated on an idealized elastic cardan shaft. The research showed that two-parameter frequency analysis can be used to generate torsional vibrations of elastic vehicle cardan shafts in laboratory conditions.
During exploitation, commercial motor vehicles are exposed to various types of loads, among which... more During exploitation, commercial motor vehicles are exposed to various types of loads, among which vibrations are of particular importance. Vibrations lead to fatigue of vehicle users and materials of their components. Therefore, they must be studied in the earliest stages of design, using mathematical models, experiments, or their combinations. In theoretical considerations, vibrations of concentrated masses are usually observed, although recently, with the development of numerical methods (especially finite element methods), attention has also been paid to the vibrations of elastic systems of these vehicles. In such cases, simplifications are usually made, especially regarding exploitation conditions and interconnections of vehicle components. This paper attempts to develop a method for identifying vibrational loads on the controlling lever under exploitation conditions, using a two-parameter frequency analysis with the use of 2 D Fourier transform. The applicability of the procedu...
Journal of Mechanical Engineering and Modern Technology, 2018
Dynamic simulation, based on modelling, has a significant role during to the process of vehicle d... more Dynamic simulation, based on modelling, has a significant role during to the process of vehicle development. It is especially important in the first design stages, when relevant parameters are to be defined. Powertrain mounting system is exposed to thermal loads which can lead to its damage and degradation of characteristics. Therefore, this paper attempts to analyse a conversion of mechanical work into heat energy by use of a method of dynamic simulation. Bearing in mind the most frequent application of classic - mechanical and hydraulic powertrain suspension in modern trucks, this paper will present analyses of thermal load of a vehicle manufactured by the domestic manufacturer FAP. The issue of heat dissipation from the powertrain mounting system has not been taken into consideration. The experimental verification of the results will be done in next investigations.
During exploitation, motor vehicles are exposed to vibrational loads that cause fatigue for users... more During exploitation, motor vehicles are exposed to vibrational loads that cause fatigue for users and material fatigue of their components. Therefore, vibrations must be studied at the earliest stage of design, using mathematical models, experiments, or a combination of both. Generally, there are idealizations during theoretical analysis, particularly concerning operating conditions and the interrelationships of motor vehicle components. This paper attempts to develop a method for identifying actual loads in continuous vehicle systems in exploitation conditions, based on recorded spatial vibrations. Multi-parameter frequency analysis was used for 2D, 3D, and 4D Fourier transformations. An illustration of the application of these procedures was carried out on idealized continuous vehicle elements such as bars, membranes, and parallelepipeds.
Tracked vehicles are exposed to vibrational loads during exploitation, which leads to fatigue of ... more Tracked vehicles are exposed to vibrational loads during exploitation, which leads to fatigue of users and materials of their aggregates. Therefore, they must be studied even in the earliest stages of design, using mathematical models, experiments, or combinations. In theoretical considerations, vibrations of concentrated masses are usually observed, although, with the development of numerical methods (especially finite element methods), attention is paid to vibrations of elastic systems of tracked vehicles. Then, usually, idealizations are made, especially regarding operational conditions and mutual connections of vehicle aggregates...
This paper attempts to develop a method for identifying real vibrational loads of the track of a tracked vehicle in exploitation conditions, using 2D Fourier transform for two-parameter frequency analysis. The illustration of the possibilities of the procedure was performed on an idealized track of a tracked vehicle. The research conducted showed that two-parameter frequency analysis can also be used to generate transverse vibrations of the track in laboratory conditions.
Suspension systems have great influence on vehicle characteristics, especially ride comfort and h... more Suspension systems have great influence on vehicle characteristics, especially ride comfort and handling. Classical suspension systems may only offer a compromise among requirements for ride comfort and vehicle handling in a narrow range of service conditions. Better characteristics are provided by application of suspension systems with controlled characteristics: semiactive and active systems. Active suspension systems introduce special force generators, power demanding, so as to obtain favourable characteristics. Their prices are fairly high, so that the application may take place in high vehicle class. Semiactive suspension is based on control of spring characteristics, or, more often, damping characteristics, providing acceptable output characteristics for medium and high class vehicles. Therefore, this paper will mostly deal with the design of semiactive suspension systems, based on control of damping parameters. A method of »stochastic parameters optimization« has been utilized for the optimization of parameters of semiactive suspension. The optimization objective was a simultaneous minimization of sprung mass vibration and standard deviation of dynamic ground reactions.
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Attention is paid to the choice of the objective function in the optimization process, with a special focus on the interrelationship of sub-objectives. The author's previously developed model of the cardan shaft and stochastic parametric optimization based on the Hooke-Jeeves method was used for the research.
The calculated values of the unknown parameters of the cardan shaft are intended to be used for the final selection of its standard dimensions in the later design phase.
OPTIMAL DIMENSIONING OF THE STEERING ROD IN THE
CONCEPTUAL DESIGN PHASE OF A COMMERCIAL MOTOR
VEHICLE
MIROSLAV DEMIĆ
Faculty of Engineering Sciences (retired professor), Kragujevac, Serbia E. mail: demic@kg,ac.rs
Abstract: The conceptual design represents the first concretization of the project task, and its main goal is to define the parameters of the driver's ergosphere and the external dimensions, mass, and performance of the commercial vehicle, as well as its stylistic indicators, necessary for further work on the project. As is known, the parameters of the steering rod are not known in the initial phase of designing a commercial vehicle, so in this paper, an attempt was made to define the necessary dimensions based on the minimization of its transversal vibrations, simultaneous minimization of mass, and maximization of the critical buckling force. For these purposes, a simplified geometric, physical, and mathematical model of the rod, the method of stochastic parametric optimization, and 2D Fourier transform were used.
Keywords: Commercial vehicle, steering linkage, transverse vibrations, mass, critical
This paper attempts to develop a method for identifying real vibrational loads of the track of a tracked vehicle in exploitation conditions, using 2D Fourier transform for two-parameter frequency analysis. The illustration of the possibilities of the procedure was performed on an idealized track of a tracked vehicle. The research conducted showed that two-parameter frequency analysis can also be used to generate transverse vibrations of the track in laboratory conditions.
Attention is paid to the choice of the objective function in the optimization process, with a special focus on the interrelationship of sub-objectives. The author's previously developed model of the cardan shaft and stochastic parametric optimization based on the Hooke-Jeeves method was used for the research.
The calculated values of the unknown parameters of the cardan shaft are intended to be used for the final selection of its standard dimensions in the later design phase.
OPTIMAL DIMENSIONING OF THE STEERING ROD IN THE
CONCEPTUAL DESIGN PHASE OF A COMMERCIAL MOTOR
VEHICLE
MIROSLAV DEMIĆ
Faculty of Engineering Sciences (retired professor), Kragujevac, Serbia E. mail: demic@kg,ac.rs
Abstract: The conceptual design represents the first concretization of the project task, and its main goal is to define the parameters of the driver's ergosphere and the external dimensions, mass, and performance of the commercial vehicle, as well as its stylistic indicators, necessary for further work on the project. As is known, the parameters of the steering rod are not known in the initial phase of designing a commercial vehicle, so in this paper, an attempt was made to define the necessary dimensions based on the minimization of its transversal vibrations, simultaneous minimization of mass, and maximization of the critical buckling force. For these purposes, a simplified geometric, physical, and mathematical model of the rod, the method of stochastic parametric optimization, and 2D Fourier transform were used.
Keywords: Commercial vehicle, steering linkage, transverse vibrations, mass, critical
This paper attempts to develop a method for identifying real vibrational loads of the track of a tracked vehicle in exploitation conditions, using 2D Fourier transform for two-parameter frequency analysis. The illustration of the possibilities of the procedure was performed on an idealized track of a tracked vehicle. The research conducted showed that two-parameter frequency analysis can also be used to generate transverse vibrations of the track in laboratory conditions.