Machinery - Repository of the Faculty of Mechanical Engineering, University of Belgrade
Not a member yet
8397 research outputs found
Sort by
Finite element analysis and machine learning based design of latticed hip implant stem
No full textDue to the increase in hip implant surgeries over the last few decades,
the design and manufacturing methods have also been improving in
order to create the optimal design that suits each individual patient
and minimizes the need for revision surgery.
This study investigates the design of hip implant stem from titanium
alloy and designed with lattice structures, furthermore produced by
additive manufacturing. A surrogate model of the latticed implant
stem was developed to replace time-consuming finite element
calculations of the very complicated structure. Machine learning was
used to predict the mechanical response of the implant stems with
different design parameters. In the knowledge of the mechanical
properties, the surgeon has the information which design fits the best
to the patient
Sustainable development and circular economy supported by artificial intelligence tools
No full textThis paper researches how artificial intelligence (AI) can support sustainable
development and the circular economy. It focuses on the use of AI tools in resource
optimization, waste reduction, and improving manufacturing processes in line with the
principles of the circular economy. The aim is to demonstrate how AI can contribute to
sustainable practices across industries, from agriculture to manufacturing and recycling,
enabling economies that minimize environmental impact. The study analyzes current AI
technologies such as data-driven optimization, predictive analytics, robotics, natural
language processing, sensor technology and their application in resource consumption
pattern recognition, product lifecycle prediction, and recycling improvements,
considering sustainability principles and environmental issues. While AI offers significant
potential, the paper also discusses challenges such as high implementation costs, the need
for training, and ethical concerns regarding data usage. The conclusion of the study
emphasizes the need for an integrated approach in AI tool implementation, with special
attention to the social, economic, and environmental aspects of sustainable development
Semielliptical Modification of the Symmetrical Dolphin 0006 Airfoil
No full textcontract number 451-03-136/2025-03/200213 dated February 4, 2025
IMPORTANCE OF AN AUTOMATIC BEE COUNTER AT THE BEEHIVE ENTRANCE
No full textThe technology of using honey bees in modern agriculture is constantly
developing. Man assisted honey bees have an important role in pollination of cultivated
and wild plant species, positively affecting quantity and quality of food and feed. Direct
bee products such as honey, collected pollen and bee bread, have a special place in human
nutrition due to their functional food properties. This beneficial insect is exposed to various
negative influences such as improper use of pesticides in agriculture, various diseases, food
shortages, and temperature fluctuations, causing weakening of bee colonies and often
complete death. Monitoring and reaction time of beekeepers in case of negative events for
the bee colony is of key importance for the survival of the colonies. Advances in technology
have led to different ways of automatically monitoring the activities of forager bees at
the entrance to the hive, such as video recording and image recognition, radio frequency
identification tags for marking and tracking bees, or opto-electric sensors that monitor
the entry and exit of bees. Automatic bee counters at the hive entrance collect the data
on worker bee traffic in real time without disturbing them. Interpretation of the results
indicates foraging activity of the bees, strength of the colony, swarming or other changes in
the bee behavior. Use of automatic counters helps the breeder to monitor bee colonies at a
distance and develop precision beekeeping.contract registration number: 451-03-137/2025-03/20010
Mould Realization and Technology Development for Different Biocomposite Specimens (Mycelium-Based Materials): Case – Three-Point Bending Test
No full textThe idea of this paper is the application of biomaterials in construction, primarily as thermal insulation materials. It is necessary to prepare biocomposite specimens to test their mechanical characteristics and behavior. This work prepared the specimens for three-point testing bending following the corresponding standards ASTM D790 (three-point bending) and ASTM D7264 (flexural stiffness and strength properties). Firstly, a 3D polymer mold prototype was developed and manufactured. After that, the technology of the biological process of the production of mycelium-based composite materials was carried out according to the appropriate procedure, where three different types of substrates with two types of granulations (fine and coarse) were used. Specimens (or plates) with a reinforced structure (where the moisture percentage was reduced to a minimum) were obtained and prepared for the mechanical characteristics testing.contract No. 451-03-65/2024-03/20010
Estimation of Hover Endurance for an Electric Multicopter with Experimental Validation of Results
No full textOne of the key characteristics of multicopters is their ability to hover precisely, which enables their use in various missions. Furthermore, electric multicopters are already widespread today due to their simplicity and ease of operation. However, they have relatively short hover endurance, making the ability to accurately determine hover time crucial. Hover endurance is calculated based on momentum theory and the application of fundamental equations. The procedure is validated through experimental results on an electric multicopter with a takeoff weight of 48.8 kg
The potential of different printing materials for 3D printed beehives
No full textThe development of 3D printed beehives represents a promising innovation in the field of apiculture, offering the potential to revolutionise hive design. The functionality of traditional wood and beeswax-based hives is endangered by various factors: beeswax mechanical strength, deterioration of the structure due to temperature variation, susceptibility to different pests, proneness for mould formation, etc. Exploring the application of 3D printing technology applied to hive construction requires consideration of factors such as durability, insulation, ventilation, topology optimisation to reduce weight and cost, ease of assembly, and bee harvesting. The choice of materials, ranging from plastic to advanced and biodegradable composites, plays a critical role in enhancing hive sustainability and overall bee health. To make 3D-printed beehives more environmentally friendly, biodegradable materials are a better choice. Some suitable options include PLA, UV-resistant nonoilen, wood-based composite filaments, and innovative materials, which contain organic components and degrade naturally over time. Nevertheless, the potential of 3D-printed structures as a viable alternative in beekeeping has yet to be fully explored, considering the unique properties of each material. Some of the problems that need to be considered are material durability, moisture sensitivity, temperature and chemical resistance, vibration resistance, UV resistance and ageing, surface roughness, and at the end, from an economic side, the cost and accessibility of different materials. This work highlights the potential of additive manufacturing technology to support sustainable beekeeping practices, considering the large variety of materials and their unique properties
CNC SIMULATOR BASED ON LINUXCNC CONTROL AND PROGRAMMING SYSTEM
No full textThis work presents a CNC simulator that was created based on the need to design and form a working environment within which training of operators and programmers of CNC machines will be carried out in an economically profitable way. The CNC simulator is based on a Raspberry PI 5 microcomputer and LinuxCNC open source software system intended for control and programming of CNC machines and industrial robots. The LinuxCNC software system was configured according to the set requirements and current needs. With the control system configured in this way, two working environments were formed that are currently used in the realization of laboratory exercises of the teaching process of the higher education institution. In the framework of the paper, the
created working environments are described, and in the conclusion, the observations obtained by analyzing the results achieved using the CNC simulator are presented.Conference proceedings [Elektronski izvor] : 60th Anniversary of the Association of Production Engineering of Serbia
/ 40th International Conference of Production Engineering ICPES 2025 - Serbia 2025, Nis, Serbia, 18th - 19th
CIP - Каталогизација у публикацији
Народна библиотека Србије, Београд
621.7/.9(082)(0.034.2)
621.7/.9:669(082)(0.034.2)
681.5(082)(0.034.2)
005.6(082)(0.034.2)
004.896(082)(0.034.2
Integrated 3D DIC and PRTS analysis of long-termdegraded power plant steel
No full textThis paper presents an experimental investigation of the stress–strain behavior of Pipe RingTensileSpecimen (PRTS) made of X20CrMoV12-1 power plant steel after 200,000 hours of service. The objective was to determine the hoop-direction mechanical response of the material using a 3D Digital Image Correlation(3D DIC) method, evaluate dimensional changes with a 3D scanning system, and record temperature field evolution using a thermal imaging camera during tensile loading. A total of 12 PRTS samples were prepared from two pipe segments: the fracture zone segment I and a straight-pipe segment II. The results show that the fracture forces of segment I specimens are lower compared to II due to material degradation near the crack region and reduced wall thickness. Cross-sectional analysis revealed pronounced ductile behavior, with an average thickness reduction of 40.1% and width reduction of 23.5%. Experimental stress–strain curves provided characteristic mechanical values, including an engineering ultimate strength of 367.47 MPa(463.4MPa true value) and a 0.2% offset yield strength of 208 MPa. Comparison with the theoretical Ramberg–Osgood curve for X20CrMoV12-1 showed good agreement in the elastic region, with notable deviations in plastic domain caused by long-term service exposure. The findings demonstrate that the PRTS methodology combined with 3D DIC offers a reliable approach for assessing material degradation and remaining load-bearing capacity of power plant tubing in the hoop direction without flattening and without introducing additional residual stresses
DYNAMIC FLEXIBLE JOB SHOP SCHEDULING PROBLEM BASED ON GENETIC ALGORITHM
No full textThe increasing frequency and sophistication of cyber-attacks on manufacturing systems demand that scheduling frameworks evolve to include cybersecurity considerations. The integration of dynamic and cybersecurity-related factors into the flexible job shop scheduling problem modelling is essential to better reflect real-world manufacturing conditions. This paper addresses the flexible job shop scheduling problem in a dynamic manufacturing environment, affected by three unexpected disturbances: the arrival of new jobs into the manufacturing system, job cancellations, and machine tool breakdowns. Particularly, some of these disturbances are caused by cyber-attacks targeting manufacturing systems, increasing risks to production and operational reliability. These disturbances have a significant impact on manufacturing efficiency, affecting delivery deadlines, resource utilization, and overall processing time. In this research paper, a genetic algorithm is applied as a robust artificial intelligence technique suitable for solving NP-hard combinatorial problems such as the dynamic flexible job shop scheduling problem. The algorithm facilitates real-time adjustment through rescheduling mechanisms, aiming to achieve a specified optimization objective – minimizing the total processing time (makespan). The proposed method is implemented in the MATLAB® environment and validated through simulations using relevant benchmark problems. Experimental results demonstrate that the proposed methodology significantly improves adaptability and performance in dynamic manufacturing environments, while maintaining high efficiency despite sudden interruptions. Overall, the proposed approach advances intelligent and adaptive real-time rescheduling in a flexible job shop environment, supporting the Industry 4.0 concept by enhancing the flexibility, efficiency, and performance of intelligent manufacturing systems that can withstand both disturbances and emerging cyber threats