Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2021
Wear of a friction pair of brake (brake disc and pads), in addition to reducing the active safety... more Wear of a friction pair of brake (brake disc and pads), in addition to reducing the active safety of vehicles, leads to the formation of particles that can affect the environment and human health. In addition to the technologies that are being developed for the collection of particles created by the wear of brakes during braking process, today new materials are being introduced, as well as various technologies for processing friction pairs with the aim of reducing brake wear and thus the formation of particles. Furthermore, today, technologies for coating (cladding) the friction surfaces of disc brakes with some materials are increasingly applied and researched, in order to reduce the wear intensity (wear rate) of disc brakes, i.e. the emission of particles created by wear of friction pairs. The aim of this paper is to analyse and review different deposition techniques and materials used for brake discs coatings, as well as the effect it has on the wear rate of friction pair. There ...
Environmental Science and Pollution Research, 2022
For achieving the desired vehicle speed, the IC engine is very important, while for further vehic... more For achieving the desired vehicle speed, the IC engine is very important, while for further vehicle speed maintaining and adaptation to road conditions, the braking system is important. With each brake’s activation, wear products are forming, which are very harmful to the environment, because they can contain heavy metals. The braking working parameters (initial speed and braking pressure) are beside the achieved temperature in contact par, the most responsible, for particle formation and their release into the air. The particles forming can be divided by size on coarse, fine, and ultrafine particles, and which were observed in the paper. However, the greatest accent was placed on coarse and fine particles. For the determination of the composition of wear products, most often, laboratory tests were used. Particle composition greatly depends on the composition of brake pads, which can consist of about 30 components, and where some of these components have very unfavourable effects on people’s health. So today, many researches are focused on finding such composition for brake pads, which will wear as less as possible, without disturbing the basic tribological properties. The conclusion of this paper shows that the applied materials for manufacturing the braking system are very important, as well as the construction, for the reduction of particle emission.
New Technologies, Development and Application II, 2019
The World Health Organization has declared pedestrians, cyclists and motorcycle, moped drivers an... more The World Health Organization has declared pedestrians, cyclists and motorcycle, moped drivers and passengers, as vulnerable categories of participants in traffic. Some of the reasons are that they often can be found in a blind spot of the cars, vans and heavy duty vehicles. Therefore, the drivers of such vehicles can’t notice them. Determination of the visual field of heavy duty vehicles’ drivers, is performed in the paper by applying Catia V5 software, module Ramsis (in case if only rear-view mirrors are used). Based on this approach, the reasons for using cameras and sensors instead of a rear-view mirror are reflected in the reduction of blind spots and reduction of the aerodynamic drag coefficient, the numerical simulation was obtained by using Ansys/Workbench 14.5 software.
The phenomenon of vehicle braking is very complex, because during the braking process, the heat w... more The phenomenon of vehicle braking is very complex, because during the braking process, the heat will be generated on the braking disc and the braking pads. This will cause the penetration in the contacting surfaces. In this research paper, three-dimensional model is developed and validated using finite element technique. It was used ANSYS/Workbench 14.5 software, Transient Structural module to achieve the numerical analysis. During the stopping process, the high temperatures appeared on the braking pads, where the temperature exceeded 150 ℃ when applied pressure is 0.9 MPa. While, when the applied pressure is 1.1 MPa the temperature on the contact surface is exceeded 180 ℃, after just 1.3 s. The important conclusion based on the results is the most significant factors on the distribution and magnitude of temperature that appear on the contact surfaces are applied pressure and the penetration. Besides that, it was found, that the penetration in high measure depends on the temperature, which proves the value of the coherence, which is almost equal to 1.
During every braking process, the wear in the contacting surfaces of brake disc and brake pads wi... more During every braking process, the wear in the contacting surfaces of brake disc and brake pads will be occurred. Therefore, it's very important to investigate the effective parameters on the wear mechanism of the contacting surfaces, this is necessary because of the lifetime of the elements of brake is proportional directly with the rate of wear. In this research paper, the influence of the applied pressure function by which brake pads act on the brake disc is investigated using finite element method. Three different functions of pressure were applied which are: constant, linear and exponential. 3D model has been developed in order to analyze the penetration in the contacting surfaces of the elements of brake system. The results presented the variation of penetration with braking time. Furthermore, the results illustrated the distributions of the contact pressure in the friction pair (inner and outer sides) at any instant during the braking process. Also, it was found that the values of stress at the end of the braking process (regardless of the contact area) were the same for all functions of the applied pressure. The differences in the stresses occurred when applied different function of pressure function during the braking process.
A B S T R A C T The introduction of the paper gives the basic concepts, historical development of... more A B S T R A C T The introduction of the paper gives the basic concepts, historical development of methods of Fault Tree Analysis -FTA and Failure Modes, Effects and Criticality Analysis -FMECA for analysis of the reliability and safety of technical systems and importance of applying this method is highlighted. Failure analysis is particularly important for systems whose failures lead to the endangerment of people safety, such as, for example, the braking system of motor vehicles. For the failure analysis of the considered device, it is necessary to know the structure, functioning, working conditions and all factors that have a greater or less influence on its reliability. By formation of the fault tree of drum brakes in braking systems of commercial vehicles, it was established a causal relation between the different events that lead to a reduction in performance or complete failure of the braking system. Based on data from exploitation, using FMECA methods, determination of the cri...
Due to the effects of excitations of road micro-roughness and the powertrain as well as due to th... more Due to the effects of excitations of road micro-roughness and the powertrain as well as due to the conditions of movement (acceleration, braking, curvilinear movement), the weights of commercial vehicles perform complex spatial oscillations. The negative impact of these movements or dynamic loads caused by them and transmitted to the supporting system of the vehicle can be reduced by a proper selection of the position and characteristics of the powertrain mounts. Elastic and damping forces in mounts perform mechanical work that turns into heat energy. Theoretical, experimental and combined methods can be used for the analysis of thermal loads of mounts. In this paper, research was carried out with theoretical methods using a mechanical model of the powertrain. Vibrations were observed on a freight vehicle powertrain of FAP 1314 middle-class vehicles. Bearing in mind the presence of classical (rubbermetal) and hydraulic mounts in modern commercial vehicles, the authors analysed the thermal loads of the mentioned vehicle type using a mathematical model.
Based on the conducted analyses, it has been proven that there is no generally accepted method fo... more Based on the conducted analyses, it has been proven that there is no generally accepted method for evaluation of characteristics and output parameters of drum brake mechanisms. Experimental research of he drum brake subsystem with brake fluid pressure in the brake cylinder as input quantity and brake torque as output quantity is presented in the paper. The obtained results show that there is a time delay between the output and input due to the response of the drum brake mechanism. This points to the deficiency of etermination of brake performance in time domain, because, in comparison, excitation and response of the system are not adequate. Hence, the dynamic mode is observed in the analysis of the drum brake ubsystem. Dynamic analysis determines the behaviour of the system in transient period. With previously known transfer characteristics of a system, its response can be determined in relation to the specified inputs (excitations), which is a good basis for determination of correl...
O metodama za proračun i ispitivanje doboš kočnih mehanizama objavljen je veliki broj radova, čem... more O metodama za proračun i ispitivanje doboš kočnih mehanizama objavljen je veliki broj radova, čemu je značajno doprineo intenzivan razvoj kompjuterske tehnike, numeričkih metoda i merne tehnike. Međutim, na osnovu sprovedenih analiza, pokazalo se da ne postoji opšte prihvaćena metoda ocene mehaničkih karakteristika i izlaznih parametara doboš kočnica. U radu je prikazan jedan pristup definisanju kriterijuma za ocenu svojstava doboš kočnica za motorna vozila. Prema predloženom algoritmu, formiraju se kompleksne karakteristike kočnih mehanizama različitih izvedbi i brzo ocenjuju karakteristike kočnih mehanizama, što je posebno važno u fazi razvoja novog proizvoda, uz upotrebu računarske merne tehnike za akviziciju i obradu podataka. Ta metoda omogućava da se, pored pokazatelja efektivnosti i stabilnosti, dobije celovita slika o ulozi doboš kočnice u kočnom sistemu vozila, proceni energetski bilans kočenja i odrede promene koeficijenta trenja primenjenog frikcionog materijala u toku probe u funkciji pritiska ili brzine kretanja vozila.
Journal of Low Frequency Noise, Vibration and Active Control, 2012
The paper presents and reviews the results of the analysis of vibrational loads of the steering s... more The paper presents and reviews the results of the analysis of vibrational loads of the steering system's tie-rod for passenger car in characteristic exploitation conditions. Experimental data are acquired using the left tie-rod's relative deformation sensor, vertical acceleration sensors at the centres of all four wheels, vertical acceleration sensor at the connecting point between the left front shock absorber and the vehicle body, longitudinal vehicle speed sensor, steering wheel angular displacement sensor and steering wheel torque sensor. Tests are performed during straight line drive and vehicle cornering, with constant and variable vehicle speed and on different types of the roads. On the basis of acquired experimental data, the influences of the inputs from the road roughness (type of the road), the steering wheel torque, the steering wheel angular displacements and vehicle speed on vibrational loads of the steering system's tie-rod loads are analyzed.
In addition to different kinds of pollutants emitted by the vehicles, noise can also negatively e... more In addition to different kinds of pollutants emitted by the vehicles, noise can also negatively effect on human health. It does not only threaten drivers, but also people living near major intersections and roads, as well as roads where traffic-flow is high. One of the biggest problems of the vehicle is the noise that occurs in the braking process. Despite the large scope of research into the development of brake systems, there are still no reliable procedures during the development phase to evaluate the robustness of these systems with respect to friction-induced vibrations. Therefore, the identification of the modal properties by using experimental methods has become even more important. Experimental and numerical modal analysis of the venting disc with radial ribs was performed in this paper. This approach enables the determination of the natural frequencies of the brake disc, as well as the verification of results obtained by the numerical methods. Changes in modal properties-resonance frequencies and modal damping values due to variation in operating conditions were also analysed.
Non-exhaust vehicle emissions are currently thought to be tyre wear, brake wear, clutch wear, roa... more Non-exhaust vehicle emissions are currently thought to be tyre wear, brake wear, clutch wear, road surface wear, corrosion of other vehicle components, corrosion of street furniture and crash barriers, and the resuspension of road dust. Among non-exhaust sources, brake wear can be a significant particulate matter (PM) contributor, particularly within areas with high traffic density and braking frequency. Regulations for brake pad performance are influenced by many bodies across the world, including the Particle Measurement Programme by the United Nations Economic Commission for Europe (UNECEPMP). In order to continuously improve their products and ensure regulatory compliance, brake pad manufacturers conduct brake performance tests and they can be carried out on vehicles and on dynamometers. The main topic of this paper regards the potential impact of the emitted PM on the human health, depending on the mechanisms of formation and toxicity of the particles. On-going European project...
In the introductory part, the history development is presented, and it points out the importance ... more In the introductory part, the history development is presented, and it points out the importance of using the Fault Tree Analysis-FTA method for analysis of the reliability and safety of technical systems. By analyzing a number of references related to the FTA method, the FTA methodology is established, and explanation of some steps by this method is given in this paper. As an example of the practical application of methods, the failure of the solar concentrators is analyzed.For the failure analysis of the considered device, it is necessary to know the structure, functioning, working conditions and all factors that have a greater or less influence on its reliability. Along with an explanation of certain parts of the fault tree, the estimation of the significance of certain events is done, and it is considered to be able to eliminate causes of failure or to minimize the consequences of failure.
The braking system is one of the most important elements in vehicle systems from the aspect of ve... more The braking system is one of the most important elements in vehicle systems from the aspect of vehicle safety, besides the steering system and the internal combustion engine. During the braking process, the disc and pads absorb a large amount of kinetic energy that converted to heat. Owing to this frictional heating, it is necessary to compute the temperature distribution that will be appeared during the braking process, which is the main goal of this research paper. There are many factors that can be influenced to the distribution of frictional heat generated. One of the significant factors is the applied pressure by the brake pad on the braking disc. The results proved that when increased the applied pressure then the frictional heat generated increased too. It was developed a new finite element model based on observed data from real vehicle. It was used ANSYS/WORKBENCH 14.5 software to perform the numerical analysis, module Transient Structural. Parts that are the most disposed t...
Proceedings of the Institution of Mechanical Engineers, Part J: Journal of Engineering Tribology, 2021
Wear of a friction pair of brake (brake disc and pads), in addition to reducing the active safety... more Wear of a friction pair of brake (brake disc and pads), in addition to reducing the active safety of vehicles, leads to the formation of particles that can affect the environment and human health. In addition to the technologies that are being developed for the collection of particles created by the wear of brakes during braking process, today new materials are being introduced, as well as various technologies for processing friction pairs with the aim of reducing brake wear and thus the formation of particles. Furthermore, today, technologies for coating (cladding) the friction surfaces of disc brakes with some materials are increasingly applied and researched, in order to reduce the wear intensity (wear rate) of disc brakes, i.e. the emission of particles created by wear of friction pairs. The aim of this paper is to analyse and review different deposition techniques and materials used for brake discs coatings, as well as the effect it has on the wear rate of friction pair. There ...
Environmental Science and Pollution Research, 2022
For achieving the desired vehicle speed, the IC engine is very important, while for further vehic... more For achieving the desired vehicle speed, the IC engine is very important, while for further vehicle speed maintaining and adaptation to road conditions, the braking system is important. With each brake’s activation, wear products are forming, which are very harmful to the environment, because they can contain heavy metals. The braking working parameters (initial speed and braking pressure) are beside the achieved temperature in contact par, the most responsible, for particle formation and their release into the air. The particles forming can be divided by size on coarse, fine, and ultrafine particles, and which were observed in the paper. However, the greatest accent was placed on coarse and fine particles. For the determination of the composition of wear products, most often, laboratory tests were used. Particle composition greatly depends on the composition of brake pads, which can consist of about 30 components, and where some of these components have very unfavourable effects on people’s health. So today, many researches are focused on finding such composition for brake pads, which will wear as less as possible, without disturbing the basic tribological properties. The conclusion of this paper shows that the applied materials for manufacturing the braking system are very important, as well as the construction, for the reduction of particle emission.
New Technologies, Development and Application II, 2019
The World Health Organization has declared pedestrians, cyclists and motorcycle, moped drivers an... more The World Health Organization has declared pedestrians, cyclists and motorcycle, moped drivers and passengers, as vulnerable categories of participants in traffic. Some of the reasons are that they often can be found in a blind spot of the cars, vans and heavy duty vehicles. Therefore, the drivers of such vehicles can’t notice them. Determination of the visual field of heavy duty vehicles’ drivers, is performed in the paper by applying Catia V5 software, module Ramsis (in case if only rear-view mirrors are used). Based on this approach, the reasons for using cameras and sensors instead of a rear-view mirror are reflected in the reduction of blind spots and reduction of the aerodynamic drag coefficient, the numerical simulation was obtained by using Ansys/Workbench 14.5 software.
The phenomenon of vehicle braking is very complex, because during the braking process, the heat w... more The phenomenon of vehicle braking is very complex, because during the braking process, the heat will be generated on the braking disc and the braking pads. This will cause the penetration in the contacting surfaces. In this research paper, three-dimensional model is developed and validated using finite element technique. It was used ANSYS/Workbench 14.5 software, Transient Structural module to achieve the numerical analysis. During the stopping process, the high temperatures appeared on the braking pads, where the temperature exceeded 150 ℃ when applied pressure is 0.9 MPa. While, when the applied pressure is 1.1 MPa the temperature on the contact surface is exceeded 180 ℃, after just 1.3 s. The important conclusion based on the results is the most significant factors on the distribution and magnitude of temperature that appear on the contact surfaces are applied pressure and the penetration. Besides that, it was found, that the penetration in high measure depends on the temperature, which proves the value of the coherence, which is almost equal to 1.
During every braking process, the wear in the contacting surfaces of brake disc and brake pads wi... more During every braking process, the wear in the contacting surfaces of brake disc and brake pads will be occurred. Therefore, it's very important to investigate the effective parameters on the wear mechanism of the contacting surfaces, this is necessary because of the lifetime of the elements of brake is proportional directly with the rate of wear. In this research paper, the influence of the applied pressure function by which brake pads act on the brake disc is investigated using finite element method. Three different functions of pressure were applied which are: constant, linear and exponential. 3D model has been developed in order to analyze the penetration in the contacting surfaces of the elements of brake system. The results presented the variation of penetration with braking time. Furthermore, the results illustrated the distributions of the contact pressure in the friction pair (inner and outer sides) at any instant during the braking process. Also, it was found that the values of stress at the end of the braking process (regardless of the contact area) were the same for all functions of the applied pressure. The differences in the stresses occurred when applied different function of pressure function during the braking process.
A B S T R A C T The introduction of the paper gives the basic concepts, historical development of... more A B S T R A C T The introduction of the paper gives the basic concepts, historical development of methods of Fault Tree Analysis -FTA and Failure Modes, Effects and Criticality Analysis -FMECA for analysis of the reliability and safety of technical systems and importance of applying this method is highlighted. Failure analysis is particularly important for systems whose failures lead to the endangerment of people safety, such as, for example, the braking system of motor vehicles. For the failure analysis of the considered device, it is necessary to know the structure, functioning, working conditions and all factors that have a greater or less influence on its reliability. By formation of the fault tree of drum brakes in braking systems of commercial vehicles, it was established a causal relation between the different events that lead to a reduction in performance or complete failure of the braking system. Based on data from exploitation, using FMECA methods, determination of the cri...
Due to the effects of excitations of road micro-roughness and the powertrain as well as due to th... more Due to the effects of excitations of road micro-roughness and the powertrain as well as due to the conditions of movement (acceleration, braking, curvilinear movement), the weights of commercial vehicles perform complex spatial oscillations. The negative impact of these movements or dynamic loads caused by them and transmitted to the supporting system of the vehicle can be reduced by a proper selection of the position and characteristics of the powertrain mounts. Elastic and damping forces in mounts perform mechanical work that turns into heat energy. Theoretical, experimental and combined methods can be used for the analysis of thermal loads of mounts. In this paper, research was carried out with theoretical methods using a mechanical model of the powertrain. Vibrations were observed on a freight vehicle powertrain of FAP 1314 middle-class vehicles. Bearing in mind the presence of classical (rubbermetal) and hydraulic mounts in modern commercial vehicles, the authors analysed the thermal loads of the mentioned vehicle type using a mathematical model.
Based on the conducted analyses, it has been proven that there is no generally accepted method fo... more Based on the conducted analyses, it has been proven that there is no generally accepted method for evaluation of characteristics and output parameters of drum brake mechanisms. Experimental research of he drum brake subsystem with brake fluid pressure in the brake cylinder as input quantity and brake torque as output quantity is presented in the paper. The obtained results show that there is a time delay between the output and input due to the response of the drum brake mechanism. This points to the deficiency of etermination of brake performance in time domain, because, in comparison, excitation and response of the system are not adequate. Hence, the dynamic mode is observed in the analysis of the drum brake ubsystem. Dynamic analysis determines the behaviour of the system in transient period. With previously known transfer characteristics of a system, its response can be determined in relation to the specified inputs (excitations), which is a good basis for determination of correl...
O metodama za proračun i ispitivanje doboš kočnih mehanizama objavljen je veliki broj radova, čem... more O metodama za proračun i ispitivanje doboš kočnih mehanizama objavljen je veliki broj radova, čemu je značajno doprineo intenzivan razvoj kompjuterske tehnike, numeričkih metoda i merne tehnike. Međutim, na osnovu sprovedenih analiza, pokazalo se da ne postoji opšte prihvaćena metoda ocene mehaničkih karakteristika i izlaznih parametara doboš kočnica. U radu je prikazan jedan pristup definisanju kriterijuma za ocenu svojstava doboš kočnica za motorna vozila. Prema predloženom algoritmu, formiraju se kompleksne karakteristike kočnih mehanizama različitih izvedbi i brzo ocenjuju karakteristike kočnih mehanizama, što je posebno važno u fazi razvoja novog proizvoda, uz upotrebu računarske merne tehnike za akviziciju i obradu podataka. Ta metoda omogućava da se, pored pokazatelja efektivnosti i stabilnosti, dobije celovita slika o ulozi doboš kočnice u kočnom sistemu vozila, proceni energetski bilans kočenja i odrede promene koeficijenta trenja primenjenog frikcionog materijala u toku probe u funkciji pritiska ili brzine kretanja vozila.
Journal of Low Frequency Noise, Vibration and Active Control, 2012
The paper presents and reviews the results of the analysis of vibrational loads of the steering s... more The paper presents and reviews the results of the analysis of vibrational loads of the steering system's tie-rod for passenger car in characteristic exploitation conditions. Experimental data are acquired using the left tie-rod's relative deformation sensor, vertical acceleration sensors at the centres of all four wheels, vertical acceleration sensor at the connecting point between the left front shock absorber and the vehicle body, longitudinal vehicle speed sensor, steering wheel angular displacement sensor and steering wheel torque sensor. Tests are performed during straight line drive and vehicle cornering, with constant and variable vehicle speed and on different types of the roads. On the basis of acquired experimental data, the influences of the inputs from the road roughness (type of the road), the steering wheel torque, the steering wheel angular displacements and vehicle speed on vibrational loads of the steering system's tie-rod loads are analyzed.
In addition to different kinds of pollutants emitted by the vehicles, noise can also negatively e... more In addition to different kinds of pollutants emitted by the vehicles, noise can also negatively effect on human health. It does not only threaten drivers, but also people living near major intersections and roads, as well as roads where traffic-flow is high. One of the biggest problems of the vehicle is the noise that occurs in the braking process. Despite the large scope of research into the development of brake systems, there are still no reliable procedures during the development phase to evaluate the robustness of these systems with respect to friction-induced vibrations. Therefore, the identification of the modal properties by using experimental methods has become even more important. Experimental and numerical modal analysis of the venting disc with radial ribs was performed in this paper. This approach enables the determination of the natural frequencies of the brake disc, as well as the verification of results obtained by the numerical methods. Changes in modal properties-resonance frequencies and modal damping values due to variation in operating conditions were also analysed.
Non-exhaust vehicle emissions are currently thought to be tyre wear, brake wear, clutch wear, roa... more Non-exhaust vehicle emissions are currently thought to be tyre wear, brake wear, clutch wear, road surface wear, corrosion of other vehicle components, corrosion of street furniture and crash barriers, and the resuspension of road dust. Among non-exhaust sources, brake wear can be a significant particulate matter (PM) contributor, particularly within areas with high traffic density and braking frequency. Regulations for brake pad performance are influenced by many bodies across the world, including the Particle Measurement Programme by the United Nations Economic Commission for Europe (UNECEPMP). In order to continuously improve their products and ensure regulatory compliance, brake pad manufacturers conduct brake performance tests and they can be carried out on vehicles and on dynamometers. The main topic of this paper regards the potential impact of the emitted PM on the human health, depending on the mechanisms of formation and toxicity of the particles. On-going European project...
In the introductory part, the history development is presented, and it points out the importance ... more In the introductory part, the history development is presented, and it points out the importance of using the Fault Tree Analysis-FTA method for analysis of the reliability and safety of technical systems. By analyzing a number of references related to the FTA method, the FTA methodology is established, and explanation of some steps by this method is given in this paper. As an example of the practical application of methods, the failure of the solar concentrators is analyzed.For the failure analysis of the considered device, it is necessary to know the structure, functioning, working conditions and all factors that have a greater or less influence on its reliability. Along with an explanation of certain parts of the fault tree, the estimation of the significance of certain events is done, and it is considered to be able to eliminate causes of failure or to minimize the consequences of failure.
The braking system is one of the most important elements in vehicle systems from the aspect of ve... more The braking system is one of the most important elements in vehicle systems from the aspect of vehicle safety, besides the steering system and the internal combustion engine. During the braking process, the disc and pads absorb a large amount of kinetic energy that converted to heat. Owing to this frictional heating, it is necessary to compute the temperature distribution that will be appeared during the braking process, which is the main goal of this research paper. There are many factors that can be influenced to the distribution of frictional heat generated. One of the significant factors is the applied pressure by the brake pad on the braking disc. The results proved that when increased the applied pressure then the frictional heat generated increased too. It was developed a new finite element model based on observed data from real vehicle. It was used ANSYS/WORKBENCH 14.5 software to perform the numerical analysis, module Transient Structural. Parts that are the most disposed t...
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