Radivoje Mitrovic

University of Belgrade · Machine Design

For a long time, and especially today, the energy crisis has been a limiting factor for the growth and development of the world economy. On the other hand, improving the reliability and readiness of energy production systems is becoming a first class priority for research and development institutions around the world. Therefore, the process of prod...

New demands placed on industry make it necessary to improve design, real-time monitoring and failure prediction methods for rolling bearings. This paper presents an approach for assessing how contact surface damage affects the vibration response of rolling bearings and how vibration-based monitoring shows the damage level of rolling element bearing...

A new model of automation of technological systems, based on the Internet, was defined as the concept of Industry 4.0, Germany in 2011. It represents an advanced model of connecting machines and computers (cyber-physical systems - CPS), their networking (cloud computing and Internet of Things (IoT)) with the widespread use of advanced artificial in...

Recently, the Covid-19 pandemic has hit the world economy as a meteor impact, provoking a truly systemic effect. It pushed the economy into pause, additionally downgrading risk appetite by persistently weakening demand, supply, employment, capital investments, and all forms of discrete investments (education, science, R&D, health care, etc.). Makin...

In 2011, the model of automatization of technological systems, based on the Internet, was defined as the concept of Industry 4.0. It represents a new model of connecting machines and computers (cyber-physical systemsCPS), their networking (cloud computing and Internet of Things (IoT)) and the widespread use of artificial intelligence (AI). This co...

The application of the basic principles of Industry 4.0 in recent years has become an imperative and synonym for sustainable and digitalized machinery and industry. The paper presents a new and wide overview of the principles of Industry 4.0 paradigm and its application in the area of machine design. Primarily, the influence of Industry 4.0 on the...

Primena osnovnih principa Industrije 4.0 poslednjih godina postaje imperativ i sinonim za održivu i digitalizovanu proizvodnju. Izlaganje u ovom radu daje jedan novi i širi osvrt na principe paradigme Industrije 4.0 i njene primene u proračunima mašinskih elemenata, njihovom radu i praćenju, a sa ciljem povećanja pouzdanosti, efikasnosti i bezbedno...

Model automatizacije tehnoloških sistema, baziran na internetu, definisan je kao koncept Industrija 4.0, 2011. godine. On predstavlja novi model povezivanja mašina i računara (sajber-fizički sistemi – SFS), njihovo umrežavanje (cloud computing and Internet of Things (IoT)) i široku primenu veštačke inteligencije (AI). Ovaj koncept predstavlja model...

Appropriate lubrication of the rolling bearing is needed to lower the friction between the surfaces in mutual contact and their wear. A lubricant should completely separate the rolling elements from the raceways. The values that affect the efficiency and regimes of lubrication are analyzed in the paper, after which it is introduced a lubrication re...

The research of the influence of housing material on operation temperature of the idler bearing assembly is presented in this paper. Several radial loads and rotary speeds were applied to the test bench to determine the transient temperature field. The results were monitored and recorded for the whole period until the temperature of the assembly re...

Based on the analogy between manufacturing and mining (i.e. ore ‘production’), smart mining has four dimensions: (i) advanced digital-oriented technologies (such as Cloud computing and the Internet of things) with automated Cyber-Physical Systems (CPSs), adaptable production processes (dependent on working conditions) and production volume control...

The influence of the running-in process operating parameters on tribological properties of the block-on-disc samples in lubricated sliding conditions is analyzed and discussed in detail. Different running-in regimes are achieved by varying the normal load and sliding speed. After the running-in period, during which the operating parameters are vari...

Magnetoplasma compressor (MPC), a type of plasma accelerators, is used for treatment and alloying of steel samples: steel 100Cr6, steel 16MnCr5 and steel 42CrMo4. The high-speed plasma flow formed within the MPC, from helium with 5% of hydrogen as working gas, is directed to the surface of the samples. The energy flux density of the plasma flow in...

Basics: Industry 4.0 is a realized reality, which already today has a growing application in medicine and dentistry. So, at this moment, its application is especially important in the fight against covid-19. Aim of the paper: The purpose of this review paper is to understand the role of Industry 4.0 in the field of medicine and dentistry and to ide...

A multi-year research carried out in the Auxiliary Machinery (AM) Sector, Kostolac Open –Pit Coal Mine (OP), has resulted in the development and implementation of an Information and Communication Technology (ICT) system for management of auxiliary machinery operation and maintenance. Starting from modern trends in ICT development, the next goal is...

This paper contains elements of a comprehensive research devoted to the dynamic behavior of radial ball bearings in real working conditions. The general motivation for this topic comes from the requirements for high performance operation of bearings within complex mechanical systems, defined in many industrial branches during the last decades. The...

New powertrain design poses new challenges in terms of driveline vibration or ultimately in terms of NVH (Noise Vibration Harshness). Current state of the technology for vibration damping in car powertrains is the so-called Dual Mass Flywheel (DMF). The paper deals with creation of MBD model of double mass flywheel based on CAD model of dual mass f...

The article discusses the influence of inert gases (carbon dioxide and nitrogen) in a mixture with natural gas on power and economic parameters of the internal combustion engine LGW 702 designed for micro-cogeneration units. The experimental measurements were made under various engine operating modes and under various compositions of fuel mixtures....

Increasing the volume of the production of vehicles with electric or hybrid powertrain also leads to specific activities for research and development in this segment. One of the current areas that present the paper deals with the idea of reducing structure-borne vibration from electric powertrain to the vehicle interior. Electric powertrain and mai...

The impact of the axial load is often completely neglected in the design of the conveyor idlers (rollers) testing machines. The subject of the present research is focused primarily on the conveyor idlers load determination by numerical simulation of the contact between the conveyor belt and idlers. A nonlinear theory of the finite element method is...

Since 2011, when Industry 4.0 has entered the scene, national programs for its development and application in national industries have been launched around the world. In the meantime, this Program has begun to develop in different countries, until now thirty seven worldwide. Industry 4.0 is Program initiated by German Government and industry as a n...

The impact of geometric parameters of teeth and lubricating oils to the efficiency of involute internal spur gears, when the transverse contact ratio is 2 < εα ≤3, has been analyzed in this paper. The mathematical model and computer program for determining the current and the effective value of the efficiency have been developed. The influence of t...

Purpose This paper aims to present the methodology to determine Archard’s wear coefficient. By applying this coefficient into the numerical simulation of wear, it is possible to predict wear without long lasting and usually expensive experiments. Design/methodology/approach To determine necessary particles of Archard’s equation and calculate wea...

The advanced development of additive technologies over the past years led to the fact that parts made by these technologies have been increasingly used in the most diverse engineering applications. One of the most famous and the most applied additive technology is 3D printing. In this paper the influence of the material type on the operational char...

Nowadays, rapid prototyping technologies are available at very affordable prices. This is the main reason why they are being used in almost all industry sectors. 3D printers are currently being widely used for rapid prototyping and development of the new products. However, taking into account the permanent progress of rapid prototyping materials me...

Monografija daje istorijski pregled svih aktivnosti i rezultata rada udruženja JuDEKO/ADEKO od njegovog osnivanja do 2018 godine.

The Cyber Manufacturing Systems (CMSs) are based on integration of the Cyber Physical Systems (CPSs) and connection between Internet of Things (IoTs) and Cloud technology (CT). These are high-level methodologies for development of new generation factories, which are more intelligent, flexible and self-adaptable. CMSs generates Big Data, horizontall...

The simultaneous activity and synergistic interplay of the hydrogen-enhanced localized plasticity (HELP) and hydrogen-enhanced decohesion (HEDE) mechanisms of hydrogen embrittlement (HE) was fully confirmed for the first time in low carbon grade 20-St.20 (or 20G, equivalent to UNS G10200, AISI 1020) steel specimens (boiler tubes) in situ enriched a...

Researchers in the field of fracture mechanics, predominantly developing appropriate solution algorithms for problems of solid bodies with cracks. Problems in mechanics generally, related with fracture and fatigue for solid bodies with various geometries of sharp notches, are studied to a much lesser extent. This situation can be explained by analy...

The proper interference fit between the joined parts is a prerequisite for an effective pressure joint. The main purpose of the pressure joint is to transfer tangential, radial and axial loads between the joined parts. In order to provide proper functioning of the machine assembly (whose component parts are connected by the pressure joints), i.e. t...

In the strides of the most advanced technological achievements, the use of polymers is becoming increasingly evident both in everyday life and in engineering practice. Complex structures made of polymers attract more attention from scientists and researchers, as their application increases in the most diverse fields of science. This phenomenon requ...

Analysis of the relevant literature has shown that only few researches are dealing with the bearings dynamic behaviour in real environmental conditions - where high concentration of solid contaminant particles is evident. There is still no established mathematical correlation between bearings vibration characteristics, working time and concentratio...

The EU-NoE aims to strengthen scientific and technological excellence by developing an integrated and interdisciplinary understanding of materials technology, and co-evolution with science, industry and society, and also by addressing the fragmentation of the European research in this area. Its main objective is to enable an open and productive d...

A large number of contemporary studies about hydrogen embrittlement confirmed the multiple effects of hydrogen and activity of the different hydrogen embrittlement mechanisms in low carbon steels. However, critical evaluation and quantification of the synergy between the hydrogen-enhanced localized plasticity (HELP) and decohesion-based (HEDE) mech...

The most common way to transfer tangential and axial loads in different types of assemblies is by interference fits. It is essential to determine interference fit parameters of pressed joints, which provides a proper function of machine part, i.e. load transfer without skidding. The analyses, test methodology and results of experimental examination...

The simultaneous activity and synergistic interplay of the hydrogen-enhanced localized plasticity (HELP) mechanisms and hydrogen-enhanced decohesion (HEDE) mechanisms of hydrogen embrittlement (HELP+HEDE) was fully confirmed for the first time in low carbon grade 20-St.20 (or 20G, equivalent to AISI 1020) steel specimens in situ charged with hydrog...

The rolling bearing, operating in a contaminated environment, may be exposed to intensive abrasive wear. When contaminant particles enter into the bearing and into the contact zone between rolling elements and ring raceways it leads to their interaction with bearing parts contact surfaces in relative motion. The interaction is based on the plastic...

Fatigue crack growth in friction stir welded T joints under three point bending is simulated numerically using the Extended Finite Element Method (XFEM). Three point bending fatigue load stress is applied at the centre of the plate opposite to the initial crack, with a ratio of stress intensity R = 0 and maximum stress σ= 10 MPa. The material prope...

Talking about the design of modern high-performance power train applications, one of the essential components to focus on are the gears. Gears convert torque and speed in a very wide power range, at low cost and with minimal losses and noise emission. However, the demands regarding cost, power density, NVH-behavior and efficiency are steadily incre...

Bearing in mind the multiple effects of hydrogen in steels, the specific mechanism of hydrogen embrittlement (HE) is active, depending on the experimental conditions and numerous factors which can be grouped as environmental, mechanical and material influences. A large number of contemporary studies and models about hydrogen environment assisted cr...

Nowadays, two most often used methods for rolling bearings condition monitoring are thermographic inspection and vibrodiagnostic. However, analysis of the relevant literature has shown that so far there is no established correlation between rolling bearings surface temperatures and measured radial vibration intensities. These variables also strongl...

This paper considers the factors that influence the heat generation within ball bearing. Various lubrication regimes are taken into consideration and a mathematical model for determination of the coefficient of heat generation is set up. Due to the complexity of mathematical tools, and in order to perform better and easier analysis of the considere...

Nowadays, despite very high precision of medical procedures and equipment, improving of pre-operative and operative processes is always desirable. This multidisciplinary paper deals with the application of 3D modelling and printing in the pre-operational planning stages in maxillofacial surgery. By applying of these methods significant benefits wer...

Characterization of metal degradation after prolonged service is necessary for evaluating component exhaustion and its remaining service capability. Martensitic steel X20CrMoV 12.1 has been extensively used as a material for tubing systems and pipelines in thermal power plants. This paper compares data provided by two imaging techniques. Following...

Horizon 2020 Idea & Project Fair, Enterprise Europe Network, Micro & Nano sector group, University of Belgrade, Faculty of Mechanical Engineering Belgrade, Serbia, 29.09.2015. Recently established Serbian Network of Excellence (NoE) in Materials Characterization aims to strengthen scientific and technological excellence by developing an integrated...

One of the most important factors influencing ball bearings service life is its internal radial clearance. However, this parameter is also very complex because it depends on applied radial load and ball bearings dimensions, surface finish, and manufacturing materials. Thermal condition of ball bearings also significantly affects internal radial cle...

The research of influence of operation temperature on the thermal expansion and main parameters of radial ball bearings is presented in this paper. The main bearing parameters are identified in accordance with the increasing requests concerning stability and load capacity. A series of finite element analyses is performed for quasi-static analysis o...

Historical, cultural, architectural heritage make up the identity of a nation. Therefore, it is imperative to protect them and preserve for future generations. In the restoration, conservation and reconstruction of the Act protected buildings, special attention should be paid to stability, in a way it does not interfere with either the external nor...

At a present level af technology, almost all machine parts are subjected to combined loads in real working condition. The aim of research described in this paper is to highlight the importance of combined load simulation for the calculation of machine parts load capacity. This research is inspired by one failure case study of hydro turbine shaft. T...

Retentive force of removable partial denture (RPD) directly depends on elastic force of stretched retentive clasp arms (RCAs). During deflection RCA must have even stress distribution. Safety factor is the concept which can be applied in estimating durability and functionality of RCAs. This study was based on analyzing properties of clasps designed...

Development of passive safety elements is a key component in the design and manufacture of railway vehicles. Proper functioning of these elements is of great importance and has a direct influence on the safety of passengers, goods and vehicles. Different types of railway vehicles require absorption elements of different geometries and absorption po...

Crossed helical gears are used in cars and many household appliances. The trend towards increased comfort in motor vehicles has led to the utilization of more than a hundred servo-drives in luxury class automobiles. Key advantages of crossed helical gears are their simple and inexpensive design, good noise performance and high ratios that can be re...

Precise determination of the time-to-failure for conveyor idlers allows the planning of regular conveyor system maintenance and well-timed replacement of worn conveyor garlands. Incidental delays in power plant coal supply leads to a significant reduction in overall thermal power plant efficiency. This paper describes a test stand for the laborator...

Transport of ground and coal at the surface coal dig in Kostolac, Serbia, is done using transportation belts (3 - 5 kilometres in length) using the systems of BTR (Bagger-Transporter-Remover) and BTM (Bagger-Transporter-Mill). The transporter belt during circular movement is suspended on carry-rollers (during transport of weight) and on support-rol...

This paper presents a comprehensive analysis of the assembly processes for single-row ball bearings. There are two different types of assembly processes, which depend on ball numbers and ball bearing ring designs. In the case of deep groove ball bearings, assembly is usually undertaken through slight deformation of the outer ring to increase cleara...

Energy efficiency is a key issue worldwide, and not confined solely to the realm of engineers. Past failures of mechanical power system components must be examined carefully in order to minimise future occurrences and increase energy efficiencies. Improved design procedures have been highly sought by engineers and researchers over the past few deca...

This paper presents a modern systematic approach to the improvement of the management system for auxiliary mechanization operations at an open-pit coal mine. The approach is based on an integrated model (IM) of business processes and information systems (IS). Within IS/ICT system development, implementation of GPS/GPRS technologies is also describe...

Development of passive safety elements is a key component in the design and manufacture of railway vehicles. Proper functioning of these elements is of great importance and has a direct influence on the safety of passengers, goods and vehicles. Different types of railway vehicles require absorption elements of different geometries and absorption po...

The gear tooth profile has an immense effect on the main operating parameters of gear pairs (load capacity, working life, efficiency, vibrations, etc). In current engineering research and practice, there is a strong need to develop methods for tooth profile optimization. In this paper a new method for selecting the optimal tooth profile parameters...

This paper describes the influence of corrosion on stress concentration factor and crack initiation at shaft-flange transition section. The real turbine shaft failure case study is used for research. This case study and numerical calculations show that the seal box solution led to constant leakage of river water in the zone of critical radius and r...