Theses (Department of Mechanical Engineering)

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Theses collection of the Faculty of Engineering.

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Megjelenítve 1 - 20 (Összesen 51)
  • TételSzabadon hozzáférhető
    Effectiveness of CBM and Industry 4.0 Technologies
    Sharma, Abhimanyu; Menyhárt, József; DE--Műszaki Kar
    This thesis investigates the effectiveness of Condition-Based Maintenance (CBM) and Industry 4.0 technologies in a manufacturing environment. CBM is a proactive maintenance strategy that uses real-time data and predictive analytics to optimize equipment performance and reduce downtime. The study focuses on the integration of advanced technologies such as IoT, big data analytics, and digital twins to enhance maintenance practices. Through a detailed case study of RAMAH Motors, the thesis demonstrates significant improvements in operational efficiency, cost savings, and equipment reliability. It concludes with recommendations for further implementation and optimization of CBM in the automotive industry.
  • TételSzabadon hozzáférhető
    Assembly design and finite element analysis of a basketball rim
    Daniel, Uduoise Osemudiamen; Bodzás, Sándor; DE--Műszaki Kar
    During the course of the educational presentation although how tedious the compilation of documents publications and books seem, I was able to learn more about to perform and render 3d and 2d models with the aid of computer aided software like solid works. And there take said design and work to analyzed through the finite element analysis method in other to truly understand the importance intricates and complexity of material selections. Now I would like to talk about the ideal rim. The ideal rim remodification I would say is the first the backboard. The rim breakaway or breakaway rim was designed with the same ideology of the flexible rim but with the exception of the movement of a joint in the pivot of the connection between the board and rim. The breakaway rim is created to fix two main functions namely to maintain the same rebound characteristics of the rigid rim to ensure consistency of play and the fact fair play is involved. And secondly to absorb the great impact of the weight of players when they hand on the rim or pull sharply on it. In other to perform this role to the maximum we will need to combine the rigid and flexible rim mechanism creating the perfect rim.
  • TételKorlátozottan hozzáférhető
    Optimization of battery cells and charging strategies for electric cars
    Krupets, Vladislav; Menyhárt, József; DE--Műszaki Kar
    This thesis examines the optimization of battery cells and charging strategies for electric vehicles (EVs) to improve their efficiency and sustainability. At the core of this research is the development of approaches to increase the performance and life span of batteries by different means of charging and encouraging a new and improved charging infrastructure. This research looks at the implementation of charging stations, including fast and ultra-fast chargers, within urban settings to help EV users gain access to charging. It points out the very important but conflicting situation between the quick charger's rate and battery life and its influence on the decline of battery capacity and performance.
  • TételSzabadon hozzáférhető
    Design and Analysis of belt conveyor using Finite element method
    Kinyua, Lynn Wanjiku; Hajdu, Sándor; DE--Műszaki Kar
    Finite element method and CAD are popular techniques that support and streamline a number of construction and simulation-related tasks. A scenario where these techniques are utilized, engineers and companies benefit from savings in terms of costs, time, and resources when this software is used. This thesis finite element approach has been utilized in design and analysis. A conveyor belt system is designed and a roller is analysed using the SolidEdge software. As the solid edge software is used for both the assembly and modeling process of the part, it is simpler to modify the model as it is being designed to match the intended size and to identify any compromises that may need to be made in order to obtain the most precise and optimum design. SolidEdge has a simple to use FEM program that facilitates analysis. It provides simulations with meshes ranging from coarse to fine, enabling accurate depiction of the forces operating on it. The simulation module makes it possible to perform analysis and prediction in order to identify the maximum projected stress that can be applied on the roller and put to use in the implementation. The roller displacement can also be observed upon implication of the force. In addition to, factor of safety of the roller can be determined once the analysis is done. The factor of safety is used to determine how much load the roller can withhold before it deforms.
  • TételKorlátozottan hozzáférhető
    Mecahnical analysis and optimization of adhesive solutions in automotive manufacturing: a study on Loctite adhesives
    Ahammed, Jishan; Domokos, István; DE--Műszaki Kar
    This thesis will provide an overview of the benefits and drawbacks of adhesive and their bonding applications in the automotive industry. Through this research, you will gain an understanding of the significance of adhesive bonding technologies over traditional joints like welded joints, in vehicle design and construction, where the reasons behind the choice of materials and procedures have been specified. This study includes an experiment that is designed to examine and verify the strength characteristics of the cyanoacrylate adhesives Loctite 402 and 408. Additionally, the comparison of the characteristics of the mentioned adhesives on the same kind of alloy materials has been discussed in this thesis. Following the cutting process, the specimens were then glued into a single-lap joint using a different glue for each specimen to compare their strengths. Following the application of adhesives, a portion of the specimens were exposed to standard room temperature and humidity levels. Subsequently, an Instron machine was utilized to conduct experimental tests on the joint of those samples using a lap shear tensile test setup. For every bonded material, the measured load values were presented separately in graphs within the Instron machine. Furthermore, this study compares the outcomes of Loctite 402 and 408 by illustrating the lap shear strength and stress-strain curve analysis. After the data was collected from the machine and exported to an Excel file for each specimen, their outcomes were evaluated to determine which one would be a better solution for automotive purposes. Additionally, it assisted us in determining how to enhance their adhesive solution and bring it into compliance with the industry standards.
  • TételKorlátozottan hozzáférhető
    Increasing efficiency and productivity in case of special machine production
    Maqbool, Zeeshan; Matkó, Andrea Emese; DE--Műszaki Kar
    Special machine production, characterized by low-volume, high-complexity projects, presents unique challenges to achieving optimal efficiency and productivity. This thesis explores strategies to address these challenges and improve overall performance within this specialized manufacturing environment, drawing on a case study of Bürkle, a leading manufacturer of custom industrial machinery. By closely examining Bürkle's production processes, the thesis proposes a framework of practical solutions to enhance efficiency and productivity. This framework may encompass strategies specifically tailored to the company's operations such as advanced planning and scheduling and creating KPIs to monitor the efficiency and productivity. The thesis examines the concept of Overall Equipment Effectiveness (OEE) as a key metric for evaluating production efficiency. It analyzes the specific factors impacting OEE at Bürkle, such as lead times, changeover processes, and limitations of standardization within their custom projects. Additionally, the thesis explores the potential benefits of implementing Customer Relationship Management (CRM) and Enterprise Resource Planning (ERP) systems to further enhance Bürkle's overall efficiency. CRM systems can streamline customer interactions, improve lead management, and foster stronger relationships, potentially leading to increased sales and project opportunities. ERP systems can integrate various internal functions like finance, inventory management, and human resources, potentially leading to improved resource allocation, streamlined operations, and better decision-making. By implementing these strategies informed by the case study of Bürkle, special machine manufacturers can achieve significant improvements in efficiency, reduce lead times, and enhance overall productivity. The thesis concludes by outlining avenues for further research and highlighting the practical implications of these findings for the special machine production industry.
  • TételSzabadon hozzáférhető
    Manufacturing design and static analysis of a gear shaft
    Okonokhua, Israel Osezele; Bodzás, Sándor; DE--Műszaki Kar
    Among the best ways to transfer power along with rotational motion, whether it involves an adjustment in speed or direction, through the point of origin to its destination is through gearing. The main functions of gears are for transferring torque as well as angular speed difference between two shafts. In the subject of gear studies, optimal design works well to ascertain the ideal gear characteristics for fulfilling design. There are multiple variables that go into gear design and iterative methods must also be used in the gear construction to maximize the gear's specifications. This present research presents a gear shaft design that is constructed with the use of SOLIDWORKS and the manufacturing process of the design done by the use of the Edgecam software and also a Finite Element Analysis (FEA) for assessing the engineering as well as vibration evaluation of an automotive gearbox component shaft with gearing. Analysis includes examining the part's displacement behavior with corresponding stress. ANSYS is used to build a 3-dimensional finite element simulation. The meshing of the model is done with the ANSYS Workbench. Boundary requirements including external loads are also utilized. The manufacturing design will be done in two parts due to the high level of complexity associated with the gear shaft. The first part will include the parametric configurations used for machining one end of the gear shaft and the second part will include the parametric configurations used for machining the other end of the gear shaft. This means that when the machining process has to be done on the CNC machine, there will be two separate CNC codes to be utilized which can run successively. During the manufacturing design phase, important information can be obtained, such as the overall time for machining of one or both ends of the gear shaft as well as the safety conditions that were utilized during the process. In order to get a better understanding of the finite element analysis operation, a bigger gear will be created and will mate with the teeth of the gear shaft model to transfer rotary motion from one gear to another. The analysis will involve the von-mises stress and total deformation that takes place at the exact point of contact between both gears based on the selected material properties for the gear models. This will result in the awareness of the changes in the mechanical properties of the gear shaft and its resulting mating gear.
  • TételKorlátozottan hozzáférhető
    Analysis and development of shop floor management in a unique manufacturing company
    Ojogbo, Udehmaguna David; Matkó, Andrea Emese; DE--Műszaki Kar
    This thesis investigates the various methodologies and intricacies involved in the operation of the shopfloor in a manufacturing company. The study focuses on Burkle Hungary kft, and their unique approach to production and tackling various operational and technical challenges involved in maintaining a well-functioning production line, as well as developing on the current ones. The importance of understanding the broad picture of the shopfloor and how it operates cannot be over-emphasized, as this dictates the smooth flow of activity across the entire production and monitors the quality and efficiency of the current processes. An in-depth analysis of the Quality, Cost, Delivery, Safety and Morale (QCDSM) technique, as used by the manufacturing company is the cornerstone of this research, along with various underlying principles and methodologies associated with shopfloor-management. A series of observational studies and analysis of company material was conducted, coupled with a comprehensive review of the relevant literature in the field of production, management and engineering processes. The benefits of the analysis of the shop floor process lies in having a much more holistic view of how the production line works, and in so doing, an improved material flow, as well as information flow occurs on the shopfloor, losses are uncovered quickly and analysis of productivity and efficacy with the help of visual management tools, is made simple, direct and effective. Information flow is crucial in ensuring operations are run smoothly, this flow of information and material bridges the gap between technicians and managers, this research shows how effective information flow coupled with the various lean techniques and methodologies, can lead to an improved and more efficient production line.
  • TételKorlátozottan hozzáférhető
    Comparison and evaluation of energy storage system
    Ogunmola, Ifeoluwa Opeyemi; Szendrei, János; DE--Műszaki Kar
    Energy storage has been a challenge right from the beginning of the renewable energy revolution, The popularity of intermittent renewable energy is growing, as the storage of fixed and mobile energy continues to be a crucial area of focus. Electricity is not capable of being stored, but it can be transformed into other forms of energy that are capable of being kept. These stored forms of energy can then be converted back into electricity as needed. Energy storage systems can utilize many technologies such as electrochemical in form of batteries, supercapacitors, Mechanical in the form of flywheels, CAES, and Pumped hydro, thermal modules, Superconducting magnetic, power to gas and hybrid systems. This study compares and evaluates the battery storage options through meticulous sizing calculations, clarifying the relationship between capacity, power, efficiency, and lifetime factors especially with regard to the recently implemented Solar Plusz Program (Napenergia’24), and power to gas, potential and hybrid storage options with the use of some formulars and calculations to consider the sizing of these technologies and compares the criteria needed for sizing. The review that was carried out shows that a hybrid energy storage system performs better in terms of microgrid stability and reliability when compared to applications that use a simple battery energy storage system with case studies. Hybrid energy storage system (HESS) is the best option for energy storage because a single energy storage system cannot meet every demand at once. So, choosing the right combination of storage solutions is essential for a system design that is cost-effective.
  • TételKorlátozottan hozzáférhető
    Investigation of tool wear patterns and their optimization in single point cutting tool
    Hitimana, Jean Pierre; Pálinkás, Sándor; DE--Műszaki Kar
    The main tasks to be elaborated in this thesis are four: The first task is an overview of the theoretical background on different tool wear patterns, this task is mainly divided into two parts. I used different bibliographies to review the existing literature to find out what recent researches say about these wear patterns, I explained and developed different tool wear patterns, their causes, and the possible methods to minimize or avoid them from happening. The second task is about creating a 3D model of the cutting tool deformation during machining. In this section, I used Solidworks software to create a 3D model of a single-point cutting tool and a cylindrical workpiece. Both models have been joined by the assembly method to facilitate the simulation as an entity-body import. The Third task is about carrying out Finite Element Analysis for the tool Pattern. I used ANSYS 2023 R1 software during this analysis. I used the Explicit Dynamics in Ansys at different depths of cut of 0.5 mm, 1mm, 1.5mm, and 2mm and the federate of 0.1, 0.2, 0.3, 0.4, and 0.5 mm/sec. The material used for the workpiece is structural steel and high-speed steel for a single-point cutting tool. After making the simulation, the final results have been evaluated. The deformation, the equivalent (Von-Mises) stress, and the reaction force have been generated. The fourth task concerns the evaluation of the results and comparison with scientific research resources. Based on the results on stress, deformation and the reaction forces found, a comparison was made and it has been found that by increasing the depth of cut and federate, the cutting force (reactive) increases and this is the major cause of the cutting tool wear.
  • TételSzabadon hozzáférhető
    Investigate the fatigue life of the PWR nuclear reactor vessel
    KALTHOUM , MHD WAFIK; Huri, Dávid; DE--Műszaki Kar
    International design regulations can be used to test and design a reactor pressure vessel. These codes give engineers proactive steps that can be taken to prevent any major catastrophes. Through the use of the ANSYS finite element program, this project examines the efficacy of the elastic-plastic limit based design approaches of the primary International Design Codes (ASME and BS). For the analysis, a standard pressurized water reactor (PWR) with a 300 MW capacity was chosen. SA-508 Gr.3 Cl.1, a nuclear grade steel, was utilized as the RPV material in the comparison. It has been determined that the design by analysis approach can be utilized to eliminate the needless caution that results from using the design by rule approach, which is covered in BS-5500 section 3. This study suggests that by applying the design by analysis approach as outlined in the ASME code, the maximum allowed pressure of the RPV may be increased by up to 26.37%.
  • TételSzabadon hozzáférhető
    Finite element modelling of frictional riveting process
    Weldeisrael, Yohannes; Pálinkás, Sándor; DE--Műszaki Kar
    This thesis covers, the overview of the theoretical background of frictional riveting from previous research papers to have a basic foundation knowledge about it. Then after that a three-dimensional model of a frictional riveting was created using a Computer Aided Design (CAD) software. SolidWorks software was chosen for this thesis because of its ability to generate 3D model. After completing the 3D model using solid-work CAD software, the material used is Aluminum alloy AA6082 as the rivet and polycarbonate as the workpiece. A finite element analysis was done using explicit dynamics in Ansys software at different angular velocities of 1500, 1800, 2100, 2400, and 2700 revolution per min (rpm) of the spindle speed during the riveting process. The simulation at different angular velocity was done and the final results were evaluated. The penetration and deformation of AA6082 aluminum alloy rivet inside the polycarbonate workpiece was generated, they showed that a satisfactory results. The optimal frictional riveting joint was at the spindle speed of 2400 RPM to reach the depth of 10mm in respect to the simulation that was carried out in explicit dynamics on the Ansys software.
  • TételSzabadon hozzáférhető
    Shape optimization of a rubber bumper by using Ansys optiSlang
    Platonov, Iurii; Huri, Dávid; DE--Műszaki Kar
    This thesis aimed to explore the application of optimization algorithms, through the shape optimization of a rubber bumper, a crucial component in automotive engineering. The ever growing complexity of engineering tasks and the demand for efficient solutions motivated me to investigate how artificial intelligence (AI) and machine learning (ML), integrated into various optimization software, can enhance and speed up the design process. Through the analysis of scientific literature dedicated to rubber materials and optiSlang optimization software, various rubber products were introduced, including their properties, usage cases, advantages, disadvantages, structural, production, and simulation-related limitations, additionally, available techniques and algorithms of optiSlang were explained, their applicability in different industries. The optimization process involves specifying the objective function, in our case, a single goal task, depreciation of a relative error function of a reaction force by modifying the inner and outer diameter of a rubber bumper and comparing it with the known optimum. During the next step specimen’s geometry was created and a finite element model was introduced, including the incorporation of constraints, loads, boundary conditions, and meshing. After confirming the mesh integrity and force convergence through different metrics and graphs, sensitivity analysis was performed. The goal was to find the connection between design parameters and the objective function while narrowing down the search space, which helped to evaluate optimal designs quicker during the comparison of optimization algorithms. Throughout testing, discrete inputs were preferred due to cost and manufacturing limitations, yet continuous variable optimization methods were also employed for their precision. While using optimization algorithms for both types of inputs, results indicated that all optimization methods yield reliable outcomes within reasonable computational timeframes, with the power of standard hardware configurations. The findings indicated the importance of selecting appropriate optimization algorithms based on the specific objectives, computational resources availability, and time constraints of the engineering task. The novel One-Click method was also highlighted, showing rapid results generation capabilities and simultaneous comparison of all available optimization algorithms.
  • TételKorlátozottan hozzáférhető
    Manufacturing design of a helicopter frame
    Shudabayev , Aslan; Bodzás, Sándor; DE--Műszaki Kar
    This paper suggests the latest manufacturing design approach of a helicopter frame, mainly involving its pattern plane creating, fabric sourcing ratio, blank design continuous layout, as well as pinpointing the pressure center point and tool design. It starts by the creation of a pattern plane where the particular geometry of each frame is specifically identified and optimal material can be identified. It entails doing a detailed research on the material qualifying- characteristics and structure- requirements while making a good use of resources without sacrificing structural integrity. Among the other vital aspects, the material utilization is an important one. The objectives of this stage are the utilization of material in the best way which leads to the waste reduction, even though the requirements need for the product should not be affected. For what now,blank layout can be discussed. On this stage a tangible form of a pattern plane is translated with the resulting piece as underpinnings for a fabrication process of a proposed object. Instead of that, properties of the materials, manufacturing restrictions, and critical parameters are studied for the blank optimizing. Another important design element, where the center point of pressure is determined, is pressure point assembly of the frame for the helicopter. Next off the paper is to design the tooling of the machines used to make the helicopter frame. This in addition to the molding, forming, and assembling of parts using dies, jigs, and fixtures creates long lasting assemblies with less error rates. Overall it can be claimed that this article has given a clear procedure of a helicopter undercarriage design, putting the utilization of material to the highest priority, strengthening structure, and the ability to boost efficiency of production through improved tool design.
  • TételSzabadon hozzáférhető
    Geometric design and fem analysis of flat form tools having length modifications
    Sun, Biyao; Bodzás, Sándor; DE--Műszaki Kar
    The main purpose of this paper is to design the geometric design of flat body turning tool and the finite element analysis of it. I introduced the geometric design of the turning tool and the content of finite analysis, and then proposed four different design schemes. Then, I drew the designed turning tool and the workpiece through 2 and 3 dimensional composition, and built a three-dimensional model. Finally, for the analysis of simulation results, I mainly carried out three aspects of analysis. Total deformation, equivalent stress and equivalent elastic strain. These three data can well analyze the stress of the turning tool in the working process, which will also make my design more accurate. By summarizing these three types of data, I got the basic data of turning tools of four different design schemes, which I also summarized in the paper. All in all, the design of these four kinds of turning tools meet the requirements.
  • TételSzabadon hozzáférhető
    Geometric notifications and comparative fem analysis for a water pump impeller
    Wang, Zhensheng; Bodzás, Sándor; DE--Műszaki Kar
    This thesis focuses on the impeller of a certain car water pump as the research object. Based on the measured point data, using the principle of NURBS surface formation, a 3D model of the water pump appliance is created by fitting the point. Based on the 3D CAD model of the water pump impeller, The CNC machining scheme of the water pump impeller is designed, simulating the tool path in the machining process, then obtaining the NC machining code. Based on the existing plate impeller and the design principle of parametric modelling, optimizing the geometric parameters of the existing water pump impeller blades and obtaining two new impeller structures. Using the FEM based on ANSYS software, analysing the strength and characteristics of these three different types of water pump impeller blades. The strength and stiffness of the impeller are researched, and verifying the rationality of the structure. A best comprehensive performance optimal impeller design model is obtained, which was used as a reference for optimization design.
  • TételKorlátozottan hozzáférhető
    Development of energy-efficient fans for ventilation of data centers
    Pernabekov, Azamat; Szodrai, Ferenc; DE--Műszaki Kar
    The study is devoted to the current issue of developing energy-efficient fans specifically designed to ensure efficient ventilation in data centers. The first task carefully analyzes and selects the most optimal fan type to meet the stringent cooling requirements of a data center. The main attention is paid to the development of an energy-efficient axial fan model and its successful integration into a computer-aided design system. Subtopics in this section include ventilation system concept, axial fan design, and efficient fan control techniques such as impeller speed control and innovative blade adjustment techniques. An important step is the design of the blades of an energy efficient axial fan, including the influence of the shape of the blade axis on the economical operation of the fan, the selection of the blade profile and the creation of the final 3D model using Solid Edge software. Next, an aerodynamic calculation of the developed fan is carried out, including splitting into a finite element mesh, setting the air flow conditions and calculating the flow rate, followed by analysis of the results. The final task of the work are devoted to assessing the performance and estimating the cost of an energy-efficient axial fan. Evaluating performance includes improving the design, using innovative control technologies and selecting the optimal material. The study ends with the calculation of the payback period, providing an integrated approach to development and a comprehensive assessment of the performance of this important component of the data center ventilation system.
  • TételKorlátozottan hozzáférhető
    3D scanning and manufacturing design of an engine piston
    Ni, Gaoyuan; Bodzás, Sándor; DE--Műszaki Kar
    The main objective of this thesis consists of developing a three-dimensional (3D) model of a piston head using Computer Aided Design (CAD) software. Although AutoCAD software is primarily focused on two-dimensional (2D) applications, it was chosen for this thesis because of its ability to generate 3D models as well. After completing the 3D model using the computer-aided design (CAD) software, I traveled to the lab and utilized the 3D scanning equipment to capture the physical piston head. I then performed a comparative analysis of the aforementioned 3D model and the scan results with the aim of identifying any potential discrepancies or inaccuracies. This stage was completed with the help of Mr. Dániel Nemes, who provided invaluable assistance throughout the process. Initial comparisons showed significant differences between the produced and scanned 3D models. Therefore, I optimized the accuracy of the piston head 3D model by optimizing it. Subsequent analysis showed that the error of the improved model was below an acceptable threshold. The third objective of this thesis was to develop a machining process for the piston head using EdgeCAM software. Proficiency in milling and turning machining techniques was achieved by exploring the relevant PDF learning resources available on the official EdgeCAM website and by utilizing instructional videos available on the Internet. During the initial design phase, I realized that the unique composition of the piston head did not allow for the use of only milling or turning methods in the machining process. Therefore, it was decided to use Solidworks software to divide the 3D model of the piston head into different parts. The upper portion of the piston head was manufactured utilizing turning machining techniques. The upper part of the piston head is manufactured by the turning machining process while the lower part of the piston head is manufactured by milling machining process. At the initial stage of the design process, it is vital to determine the appropriate blank for the machined object. Subsequently, fixtures and machine tools must be set up accordingly. The EdgeCAM 3D model is then utilized to determine the specific features to be machined. Finally, the machining design is carried out, including determining the relevant cutting tools, the type of machining (e.g. rough turning, rough grooving, finish grooving) and the specific type of machining based on the feature to be machined. In turning, different operations such as rough turning, rough grooving, finish turning, finish grooving, and cut-off require the adjustment of specific parameters for each operation. Similarly, milling encompasses a variety of machining techniques, including roughing, contour milling, and face milling. The final goal was to optimize the machining process design. I successfully optimized the milling process for the lower part of the piston head on two occasions, reducing the machining time from 51 minutes to 13 minutes the first time and 9 minutes the second time.
  • TételKorlátozottan hozzáférhető
    Investigation of Design Factors of Drive Systems for Hydraulic Pumps
    Ashraf, Usman; Hajdu, Sándor; DE--Műszaki Kar
    This thesis, titled "Investigation of Design Factors of Drive Systems for Hydraulic Pumps," systematically addresses critical aspects influencing hydraulic pump system functionality and design. The study focuses on four main objectives. Firstly, it comprehensively examines the fundamental components and design features of hydraulic pumps, laying a crucial foundation for subsequent analysis. Next, precise calculations determine the optimal drive system, emphasizing compatibility, efficiency, and reliability. The research progresses to creating a detailed Computer-Aided Design (CAD) model, enhancing spatial understanding and serving as a platform for further optimization. The final objective emphasizes constructing the pump system's base frame, involving meticulous analysis of material, structure, and alignment for longevity and suitability. The insights gained contribute to advancing hydraulic technology, ultimately enhancing fluid power systems' effectiveness and durability.
  • TételKorlátozottan hozzáférhető
    Hőre lágyuló kompozit féknyereg végeselemes modellezése multiscale anyagmodell segítségével
    File, Máté; Huri, Dávid; DE--Műszaki Kar
    A dolgozatom során egy termoplasztikus kompozitból készült féknyereg végeselemes modellezését végeztem el, melyet az osztrák Johannes Kepler Universität Linz, Institute of Polymer Product Engineering (JKU IPPE) intézettel közösen dolgoztam ki. A modellezési feladat elvégzéséhez egy anyagi szintű visszafejtő tervezési eljárást dolgoztam ki, multiscale anyagmodellek és az ilyen modellek által nyújtott lehetőségek felhasználásával. A féknyereg alapanyaga egy PPS (polifenilén-szulfid) kompozit véletlenszerű orientációjú karbonszálerősítéssel, a laboratóriumi vizsgálathoz felhasznált próbatestek pedig egyirányú szálerősítésűek voltak. Szobahőmérsékleten és 150 °C-on szakítóvizsgálatokat végeztem különböző orientációkban. A szakítóvizsgálatok elvégzése után mikroszkópos vizsgálat és képelemzés segítségével meghatároztam az alapanyag szál kitöltési tényezőjét. A mért értékek alapján létrehoztam a kiinduló egyirányú szálerősítésű alapanyag multiscale modelljét. A Multiscale Designer szoftver egy optimalizáló eljárás segítségével kiszámította a 0°-os és 90°-os próbatestek által szolgáltatott értékek alapján az alapanyagot felépítő szálerősítés, illetve mátrixanyag mechanikai tulajdonságait. Az így létrejött modellel elvégeztem a 45°-os próbatest végeselemes szimulációját, majd ezt összehasonlítottam a mért értékkel, mely 8%-os relatív hibát mutatott. Ugyanezen eljárást elvégeztem a magasabb hőmérsékletű eredmények esetében is, ebben az esetben magasabb, 24%-os hiba mutatkozott, mivel a modell létrehozásához is a szobahőmérsékleten mért eredményeket használtam fel szálirányban. A szobahőmérsékletű és 150°C-os mechanikai paramétereket felhasználva lineáris interpolációval egy harmadik modellt is létrehoztam a 120°C-os hőmérséklethez. Az anyagmodellek által szolgáltatott mátrix, illetve szálerősítés mechanikai tulajdonságokat ezután bemenő paraméterként használtam egy-egy véletlenszerű rövidszál erősítéshez alkalmazható anyagmodell létrehozásához. A modellekhez a mért szál kitöltési tényezőt használtam fel ebben az esetben is, a véletlenszerű szálerősítést pedig kvázi-izotropként kezeltem. Az így létrehozott anyagmodelleket használtam fel a féknyereg szimulációjához. A féknyereg szimulációjakor az összeszerelés és a maximális féknyomás általi terheléseket vizsgáltam meg. A féknyereg a szimulációk alapján nem felelt meg a támasztott követelményeknek, mivel a 120°C-os és 150°C-os hőmérsékletek esetén a két fél szétnyílásának mértéke meghaladta az 1 mm-t. A nagy mértékű alakváltozás a kapcsolódó alkatrészek károsodását, illetve a fékhatás csökkenését, megszűnését okozhatja. Az alapanyag a szimulációk által szolgáltatott eredmények alapján nem alkalmazható a féknyereg esetében.