12 research outputs found
Calibration of single cylinder four stroke computer control engine by changing inlet manifold dimensions with bio-based tri-fuel
No full textCalibration of single cylinder four stroke computer control engine by changing inlet manifold dimensions with bio-based tri-fuel
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Metal matrix composites reinforced with diamond particles
No full textDissertação de Mestrado Conjunto Europeu em Tribologia de Superficies e Interfaces apresentada à Faculdade de Ciências e TecnologiaMaterials surface modification aims for the development of new material’s surfaces throughdifferent methods to improve their structure, phase composition, tribological, physical andmechanical characteristics in addition to their chemical composition. Future of glass industrypasses through solving the plunger surfaces modification to reduce friction and wear duringblowing or pressing stage of production. This thesis aims to study the modification of plungersurfaces through the design of metal matrix composite material located on the surface of Cu-BeCo substrate, reinforced with diamond particles, which surfaces will be functionalized with a lowmelting alloy to improve the adherence of diamonds. Metal matrix from Cu-Be-Co substrate’sreinforced by of diamond particles with a low melting alloy of copper-tin-titanium.Mechanical alloying through Ball milling technique has been simultaneously used to designthe low melting Cu-Sn-Ti alloy and diamonds surface functionalization. The 4.81 gr of powderparticles ( 10 % of diamonds, and the remain composition from 75% wt of Copper 15% wt of Ti,10% of tin and 1-3% of stearic acid) have been mixed and alloyed into an 80 ml vessel. Thesubstrate Cu-Be-Co surface’s texturized by laser to produce a pattern on the surface as a matrix,then functionalized diamond particles will be introduced into the matrix by cold isostatic press andsintering. For interpretation of the result, the main experimental procedures have beeninvestigated to characterize the properties of substrate (Cu-Be-Co), functionalized diamondparticles (diamond + Cu-Sn-Ti +stearic acid) and the metal matrix’s composites reinforced bydiamond particles. Hardness testing, X-Ray Diffraction (XRD), Scanning Electron Microscopy(SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and tribological testing Pin-on-desk testsperformed as characterization techniques.Despite the presence of a variety of oxides, the reinforced material exhibited better tribologicalperformance than the unreinforced Cu-Be-Co when tested on a pin-on-disk. As a consequence,significantly reduces of wear resistance and coefficient of friction attained, up to 12 times lowerwear rate and 11% reduce of COF respectively.Materials surface modification aims for the development of new material’s surfaces through different methods to improve their structure, phase composition, tribological, physical andmechanical characteristics in addition to their chemical composition. Future of glass industrypasses through solving the plunger surfaces modification to reduce friction and wear duringblowing or pressing stage of production. This thesis aims to study the modification of plunger surfaces through the design of metal matrix composite material located on the surface of Cu-BeCo substrate, reinforced with diamond particles, which surfaces will be functionalized with a lowmelting alloy to improve the adherence of diamonds. Metal matrix from Cu-Be-Co substrate’sreinforced by of diamond particles with a low melting alloy of copper-tin-titanium. Mechanical alloying through Ball milling technique has been simultaneously used to designthe low melting Cu-Sn-Ti alloy and diamonds surface functionalization. The 4.81 gr of powderparticles ( 10 % of diamonds, and the remain composition from 75% wt of Copper 15% wt of Ti,10% of tin and 1-3% of stearic acid) have been mixed and alloyed into an 80 ml vessel. Thesubstrate Cu-Be-Co surface’s texturized by laser to produce a pattern on the surface as a matrix,then functionalized diamond particles will be introduced into the matrix by cold isostatic press andsintering. For interpretation of the result, the main experimental procedures have beeninvestigated to characterize the properties of substrate (Cu-Be-Co), functionalized diamondparticles (diamond + Cu-Sn-Ti +stearic acid) and the metal matrix’s composites reinforced bydiamond particles. Hardness testing, X-Ray Diffraction (XRD), Scanning Electron Microscopy(SEM), Energy Dispersive X-Ray Spectroscopy (EDS), and tribological testing Pin-on-desk testsperformed as characterization techniques.Despite the presence of a variety of oxides, the reinforced material exhibited better tribologicalperformance than the unreinforced Cu-Be-Co when tested on a pin-on-disk. As a consequence,significantly reduces of wear resistance and coefficient of friction attained, up to 12 times lowerwear rate and 11% reduce of COF respectively
Self-powered online practical machine condition monitoring and wireless communication achieved on integrated, efficient, and durable triboelectric nanogenerator
No full textTriboelectric nanogenerator (TENG) can effectively scavenge ambient mechanical energy with cost, weight, and effectiveness advantages despite critical issues of TENG such as integration to complex components, low current output, and durability. In this work, we designed an adaptive TENG on a mechanical shaft for harvesting rotational energy which can easily assemble and disassemble. The proposed TENG presents an excellent performance for a wide range of rotational speeds (0–2000rpm) and delivers a high power of up to about 80mW (a high short circuit current of 3mA) for a size of 216 cm3, which is high enough for many types of machine condition monitoring purposes. The designed TENG has been evaluated under the noncontact mode of operation within a 0–0.5mm gap between TENG films. The TENG demonstrates excellent electrical stability of 99% without surface wear under noncontact mode within the whole test period for continuous operation of 420,000 cycles. The contact mode with a contact pressure of 0.76 Pa results in 90% electrical stability and apparent surface degradation. Moreover, it is demonstrated that the proposed TENG can power a wireless vibration sensor (60 mW) within 10 minutes energy harvesting for 9 seconds to send data via Bluetooth to a smartphone at up to 30 m, and a wireless temperature sensor (1.2 mW) in real-time for machine condition monitoring.Validerad;2024;Nivå 2;2024-03-18 (hanlid);Full text license: CC BY</p
Machine condition monitoring enabled by broad range vibration frequency detecting triboelectric nano-generator (TENG)-based vibration sensors
No full textVibration analysis is an efficient method to monitor machine condition status. Different types of vibration sensors, such as microelectromechanical, and piezoelectric accelerometers have been used to measure vibrations, but face the problems of relying on external power and high cost. Recently, triboelectric nano-generator (TENG)-based vibration sensors have attracted attention to solve these problems. However, previous studies on TENG-based mechanical vibration sensors are limited to a low-frequency range (less than 200 Hz), which is below industry machine condition monitoring requirements (often 10-1000 Hz). This work aims at enabling TENG-based vibration sensors for higher frequencies and a broad range of frequency detection through structural design supported by numerical simulations. Numerical simulation results indicate that the frequency detection range is controlled by structural design and can be easily expanded for high-frequency detection by reducing the size and improving the shape of the structure. Spring-assisted TENG-based vibration sensors with the possibility of detecting the vibration within 0-1200 Hz, which covers the major mechanical failures and imperfections in vibrational frequency ranges, are prepared according to the structural design and numerical simulation results. The experimental results show that the developed sensor successfully detects signals within the frequency range of 0-1200 Hz. Due to optimized structural symmetry and effective spring stiffness, the two spring-assisted (TS) structures generate higher electric signal output (up to 200 V and 0.9 µA). The prepared TENG vibration sensors are further compared with a high-quality commercial vibration sensor in terms of vibrational signal response and detecting bearing defects. The results show that the prepared TENG vibration sensors can provide at least the same function as the commercial vibration sensor and demonstrate a promising potential to detect machine working conditions.Validerad;2022;Nivå 2;2022-06-09 (hanlid)</p
Small Size and Low-Cost TENG-Based Self-Powered Vibration Measuring and Alerting System
No full textVibration measurement systems containing sensors, signal conditioning, and data acquisition devices, are important for monitoring motors, gearboxes, turbines, etc. Microelectromechanical and piezoelectric sensors are predominantly used for vibration measurements. However, they are not cost-effective, flexible in design, and incapable of self-powering. Recently, triboelectric nano-generator (TENG)-based vibration sensors have been considered as a possible alternative to resolve this problem, and tremendous progress has been achieved. Previous work on TENG-based sensors is limited to optimizing the sensor design, while the signal conditioning and data acquisition of TENG signal still need investigation for actual applications. This work develops a TENG-based vibration measurement device and self-powered alerting system that is integrated with the signal condition and data acquisition systems. The experimental results show that the proposed measurement system successfully measures signals within the range of 0–1800 Hz frequency. Meanwhile, the TENG generates a high output, up to 80 V and 0.55 µA from small size TENG area (3.6 cm2). The signal is adequate to harvest energy for self-powering to drive alerting components (harvest 320 mJ in 36 h, which drives alarming for duration of 1.5 s). The proposed device is cost-effective (30 $), small (105 cm3), and consumes less power (0.18 W) in comparison to commercial devices.Validerad;2023;Nivå 2;2023-07-05 (hanlid)</p
Fabrication and Mechanical Property Evaluation of Ethiopia Banana Fiber Reinforced Polymer Composites
No full textBanana and false banana fiber is important by-product of Ethiopian country farmers. The current work explains the characterization of different weight of a composite, natural fiber epoxy composites, by using hand lay-up technique and mechanical testing machine. Depending on the percentage of composite in resin, from 80%-95% by weight, which increasing the mechanical properties. SEM using to evaluate fiber, surface structure and fractured internal structure. The Experiment outcome illustrate that the impact strength, tensile strength and flexural strength are increased with the similar proportion as amount of epoxy (resin) increased. Scanning electron microscopy used to evaluate and analyze the experiment work. As well as form experimental result conclude that higher tensile, Impact and flexural strength exist at proportion of 80% epoxy resin with 20% banana fiber
Durable Self-Powered Wireless IoT Machine Condition Monitoring System Based on an Auto-Switching Non-Contact Centrifugal TENG
No full textThe long-term intelligent machine condition monitoring system is essential in improving maintenance costs and decision-making. Triboelectric nanogenerator (TENG) has a great advantage in developing self-powered machine condition monitoring. The main issues preventing TENG for such applications are poor integration to machine components, limited operational range, and weak durability. In this work, durable non-contact TENG energy harvester adaptive is designed to mechanical shafts for harvesting rotational energy. The harvester is designed to automatically switch to the non-contact mode by using centrifugal force to avoid manual switching while operating over a wide range of speeds of 0–2000 rpm. The designed TENG generates a high output of up to 25 mW with excellent stability for >20 days of continuous operation and exhibits a high-power density of 286 W m−3. Moreover, a self-powered long-term continuous condition monitoring system is developed from a TENG sensor, energy harvester, and wireless module. The developed system successfully sends possible machine fault frequency every 74 min to the cloud and accessible anywhere. This is the only TENG design reported in the literature that can fully power a Wi-Fi module to send data. Hence, the result promises the practical application of the system in developing internet of things (IoT) in the Industry.Validerad;2025;Nivå 2;2025-05-23 (u2);Full text license: CC BY 4.0;</p
