Mechanical and Industrial Engineering

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Design of Fuzzy logic controller to series active variable geometry suspension system of automobile vehicle using full car model (With preview road profile information)
(Mekelle University, 2024-04-07) Binyam Tadros
Recent advancements in electro-mechanical active suspensions are presenting new opportunities, showcasing numerous benefits over traditional passive and semi-active systems, while also overcoming the significant drawbacks of other active solutions. This thesis introduces fuzzy logic controller with perfect preview information to improve the performance of Series Active Variable Geometry Suspension (SAVGS), which enhances conventional independent passive or semi-active suspensions by actively regulating the suspension geometry through an electromechanical actuator. The research work explores the benefits of this suspension type and provides an in-depth analysis of its simplest form. Additionally, it offers insights into the design process, including liberalized full-car modeling and selection. A control system designed to manage pitch and roll attitude of the chassis is also discussed. Simulation results demonstrate the viability of the proposed system as the fuzzy logic controller (FLC) is developed using MATLAB-Simulink for the SAVGS improves the suspension system, with various performance metrics (Passenger Ride Comfort, Suspension Safety, and Road Handling) evaluated at different speed for Road disturbance. The performance response at 20 kilometer per hour shows improvement in all the performance metrics, like in Passenger ride comfort is reduced in Vertical acceleration by 41.67% with reduced pitch and roll acceleration, Suspension safety is reduced in suspension deflection by 49.1% in front and 43.1% in rear sides with reduced velocity, and in road handling the tire deflection reduces by 46.3% at front and 36.9% at the rear sides of the car
Feasibility Study of Integrated Hybrid Energy System for off-Grid Rural Electrification: Case of Three Village
(Mekelle University, 2024-09-28) Yeshareg Yrgalem
This research presents a feasibility study of an integrated hybrid energy system designed for off grid rural electrification in three villages in Ethiopia's Tigray region. With over 56% of Ethiopia's population lacking access to electricity, the National Electrification Program (NEP) aims to achieve universal electricity access by 2025, promoting a mix of grid and off-grid solutions. This study explores the potential of combining wind, solar, and biogas to create a sustainable energy model that aligns with the NEP's objectives. The objectives of this study are threefold: to assess the renewable energy resources available in the selected villages, to design and size the components of a hybrid energy system, and to evaluate the technical and economic feasibility of the proposed solution. The methodology involves data collection through site assessments, resource evaluations, load estimations, and modeling using the HOMER Pro software. The study evaluates the energy demands of Felege Mayat, May Shih, and Mayderhu villages, revealing daily energy requirements of 1673 kWh, 1215 kWh, and 785 kWh, respectively. The findings indicate that a hybrid system—combining wind, solar, and biogas—can deliver a sustainable, reliable, and cost-effective electricity supply, with levelized costs of electricity (COE) at $0.0139/kWh, $0.0158/kWh, and $0.0167/kWh for each village. This approach not only addresses the immediate energy needs in these rural communities but also promotes environmental sustainability by reducing dependence on traditional biomass. In conclusion, this thesis highlights the potential of integrated hybrid energy systems to bridge the energy gap in rural Ethiopia, promoting sustainable development and improving human wellbeing. Recommendations for future research and implementation strategies are provided to facilitate the adoption of such systems in similar contexts.
Design and Experimental Evaluation of passive Solar Still under hottest and driest climate condition of Ethiopia: A case of lake-Afdera saline water
(Mekelle University, 2024-12-25) Mohammed Ahmed Yasin
Access to potable water remains a critical challenge globally, particularly in arid regions such as Ethiopia's Afar Region, where groundwater is often limited or contaminated with high levels of fluoride and salinity. This study investigates the design and performance of passive solar stills for desalinating saline water from Lake Afdera under extreme climatic conditions. The objective was to enhance the productivity of conventional single-slope, single-basin solar stills by incorporating black volcanic rocks as thermal energy-absorbing materials. Two solar still configurations a conventional design and a modified design with black volcanic rocks were constructed and experimentally evaluated over two days in Afdera. Parameters such as ambient temperature, water temperature, and hourly yield were recorded. To validate the results, the modified still was later tested under different environmental conditions at Mekelle University using thermocouples, PicoLog software, a pyranometer, and measuring jars for precise data collection. Results showed that the modified solar still significantly outperformed the conventional still in water yield, producing 3,482 ml and 3,800 ml over two days compared to 1,920 ml and 1,780 ml, respectively. It also demonstrated improved night-time performance, yielding 890 ml versus 340ml, due to better heat retention from the black rocks. Correlation analysis from the Mekelle validation indicated strong relationships between water yield and solar radiation (r = 0.60), rock temperature (r = 0.96), internal temperature (r = 0.85), and ambient temperature (r = 0.83). The modified system achieved 32.87% higher efficiency in Afdera than in Mekelle, highlighting the role of environmental conditions. The findings confirm that integrating black volcanic rocks into solar still design enhances efficiency and output, offering a cost-effective and sustainable desalination solution for arid, high radiation regions like Afar.
Experimental Study on the Effect of Operating Parameters on Hydrogen Production from Alkaline Wastewater Electrolysis
(Mekelle University, 2024-12-28) Yibrah Gebrecherkos
This study investigated the influence of three principal operating parameters on hydrogen production from alkaline wastewater electrolysis. Hence the primary objective of this study was to examine the effects of specific operating conditions on hydrogen yield, employing alkaline wastewater as electrolyte. The key parameters examined included temperature variation, effect of electrolyte concentration variation, and applied current variability. The findings indicated that electrolysis performance was significantly influenced by these parameters. Specifically, the volume of hydrogen produced rose with rising current. At the tested currents of 0.3A, 0.5A, 0.7A, and 0.8A, the time needed to reach 10 ml of hydrogen was 664.88s, 349.24s, 244.21s, and 230.08s, In addition efficiency rose with each added current, 41.122%, 46.973%, 50.322%, 47.982%, and 44.562%. Higher applied currents initially enhanced the yield. However, beyond a certain threshold, further increases in current lead to a decline in efficiency owing to limitations in mass transport and bubble formation in and around the cell. Regarding the effect of temperature and electrolyte concentration on the rate of hydrogen production, as the temperature raised at 10 K intervals (303.15, 313.15, 323.15, 333.15, and 343.15 K), the time needed to reach 10 ml of hydrogen by volume reduced in higher order of magnitude (312.61, 267.61, 233.96, 189.72, and 184.18 s, respectively). In addition, the efficiency of the hydrogen production rate improved at each added current: 45.173%, 51.84%, 56.623%, 62.31%, and 67.735%. Although high temperatures improve efficiency, they are not favored because of the higher operating costs. The effect of the electrolyte concentration was also significant in terms of the hydrogen rate. At a current of 0.25 A for all ranges of concentration tested (5, 10 g/l; 15g/l and 20 g/l NaOH), the time(s) to reach 10 ml by volume of hydrogen was 341.58s, 276s, 236.18, and 209.57 s, respectively. This was due to the higher ionic mobility with an enhanced concentration of the electrolyte. Generally, the hydrogen production yield reached approximately 57% efficiency at a temperature of 323.15 K, current of 0.6A, and concentration of 10 g/NaOH from the alkaline wastewater, highlighting the potential of this method for generating hydrogen from an abundant and environmentally friendly resource. Future research should focus on further optimization strategies, long-term stability of electrodes in wastewater electrolysis, and economic feasibility of scaling up this process for practical applications.
POSITION AND ORIENTATION CONTROL OF A 6-DOF ROBOT USING FEEDFORWARD ANFIS-PID CONTROLLER
(Mekelle University, 2024-12-28) Gebrekiros Haile
Robotic systems with six degrees of freedom (6-DOF) have become essential in high-precision tasks such as industrial welding and surgical operations. These systems necessitate sophisticated control strategies to address the complexities of nonlinear dynamics, actuator behaviors, and external disturbances. In this research, a feedforward Adaptive Neuro-Fuzzy Inference System (ANFIS)-PID controller was developed for the precise position and orientation control of a 6-DOF robotic manipulator. The kinematic model of the robot was formulated using the DenavitHartenberg (DH) convention, allowing for the derivation of forward and inverse kinematics. The accuracy of the kinematic model was verified through simulations conducted in MATLAB. A dynamic model, which integrated actuator dynamics for all six joints, was developed using MSC Adams and validated in a co-simulation environment. This high-fidelity model enabled the realistic simulation of the robot’s mechanical and dynamic behavior. The ANFIS-PID controller was designed and tested within a MATLAB/Simulink co-simulation environment, which interfaced seamlessly with the dynamic model from MSC Adams. The performance of the developed controller was evaluated in terms of trajectory tracking and disturbance rejection. Results indicated that the controller significantly outperformed traditional PID controllers, achieving position errors below 0.3° under normal and disturbed conditions. These findings highlighted the ANFIS-PID controller’s adaptability to nonlinear dynamics and superior performance in comparison to its conventional counterparts. Despite its successes, limitations were identified. Factors such as link elasticity and joint friction were not incorporated into the dynamic model, and the training of the ANFIS model was constrained by computational resources. These omissions have been recommended for future research to enhance the model’s accuracy and real-world applicability. Nevertheless, the objectives of this research were achieved, and the potential of hybrid controllers in addressing the challenges of robotic control systems was demonstrated.
DETERMINATION OF SPECIFIC HEAT CAPACITY FOR FOOD ITEMS
(Mekelle University, 2025-02-25) Goitom Zeberhe Gebeya
The primary objective of this study was to determine the specific heat capacity of various food items experimentally. The study involved the development of the experimental setup and the execution of the experiment on some selected food items. An indirect calorimetric method of mixture experimental setup has been developed to determine the specific heats of some selected foods and prepared traditional foods mainly found in Ethiopia, which is commonly known as Injera. This method involved the modification of a heat preservation portable food storage container, purchased from a local market, to serve as a calorimeter. The calorimeter utilized in this study was a 1.9-liter wide-mouth, vacuum flask designed to keep food at a desired temperature for an extended period by minimizing heat transfer with its surroundings. Initially, four runs were conducted for the determination of the calorimeter’s specific heat capacity by employing hot water, which is found to be an average 1.003 kJ/oC. It is important to note that the plastic pouch is considered to be an integral component of the calorimeter, as both the calorimeter and plastic pouch were acquired from the local market. To prevent direct contact between the food sample and the heat exchange medium within the calorimeter, the food sample was placed within the plastic pouches. Consequently; the assessment of heat solution for dissolved chemicals in food was eliminated. The specific heat values of carrots, potatoes, onions, cabbage and Injera using predictive models at an average temperature were determined as 4.365, 4.086,4.423, 4.505 and 3.433 kJ/(kg oC), and the experimental results of these foods were found to be 4.671, 4.290, 4.688, 4.820 and 3.710 kJ/(kg oC) respectively, here the same amount of mass of samples and water, materials and methodology, by the indirect method of a mixture of calorimetry is used. Also four trials are were conducted for the determination of the specific heat capacity of potatoes, carrots, onions, cabbage and Injera. The comparison between the experimental and the predictive models exhibited an excellent level of agreement with percentage error of 5% to 10% for the above foods. This indicates that experimental specific heat capacity measurement is consistent and validate with the predictive value within an acceptable range of error.
Improving plant availability through Effective Maintenance System: A Case Study in MESSEBO CEMENT FACTORY
(Mekelle University, 2025-02-28) Araya Tesfahun
Corrective maintenance technique is have long been one of an obstacle to Messebo cement factory’s efforts to maintain high plant availability. In the fiscal year 2023/24 MESSEBO cement factory is experiencing suboptimal operational efficiency due to the persistently low availability of critical machinery across its production lines. Key equipment essential for raw mill processing, clinker production, cement milling, and packaging is operating below industry- standard availability benchmarks (85-90%), leading to reduced production capacity, increased downtime costs, and potential delays in meeting customer demand. This research examines the existing maintenance system on plant availability and over all equipment effectiveness (OEE) in the context of messebo cement factory. The study’s main objectives were to assess current maintenance procedures, pinpoint the underlying reasons for outages, and suggest workable plans to improve operational effectiveness through manpower development, predictive technology, and infrastructure improvements. The research used mixed- methods quantitative and qualitative approach, through a comprehensive case stud approach analyze maintenance data in terms of performance metrics and downtime cases. The research findings highlighted several critical issues. A reactive maintenance culture prevailed, with over 56% of respondents indicating that preventive tasks were often skipped during peak production periods. Aging infrastructure and unstable power supply led to more than 30 major equipment failures annually. Furthermore, outdated manual record keeping practices undermined data accuracy, despite 83% participants acknowledging the link between downtime and the absence of predictive maintenance. Despite these challenges, the study identified several opportunities for improvement. Notably, 60% of the workforce expressed support for modernization efforts, while 50% believed that real-time monitoring systems could significantly enhance decision making and efficiency. The research recommended immediate piloting of IOT sensors on critical equipment (e.g, cement mill rollers), enforcing strict PM via digital checklists. Medium term strategies include CMMS implementation for centralized planning and predictive analytics, alongside specialized maintenance team training. Long term goals target transitioning to predictive maintenance (aiming for 20-40% downtime reduction), fostering cross departmental collaboration through shared KPIs, and securing leadership support by demonstrating ROI
Integral Sliding Mode Control of Steer by Wire System
(Mekelle University, 2025-03-04) FRANKO MEZGEBO TESFAY
This thesis presents the design and simulation of an Integral Sliding Mode Controller (ISMC) for a Steer-by-Wire (SBW) system, aimed at achieving robust and precise steering control under uncertainties such as parameter variations, external disturbances, and varying road conditions. The proposed system tackles these challenges by integrating a sliding surface with an integral action, enhancing transient performance and disturbance rejection. The dynamic model of the SBW system, including actuator and steering mechanics, is explicitly developed prior to simulating the controller. The ISMC is formulated by designing a nominal control law based on the ideal dynamics of the SBW system, disregarding uncertainties. A switching control action is then incorporated to handle matched uncertainties, ensuring that performance criteria optimized under the nominal model remain unaffected. To further improve the system, a boundary layer is introduced to mitigate chattering, resulting in smooth and efficient control actions. Comparative analysis with Conventional Sliding Mode Control (SMC) demonstrates the ISMC's superior tracking accuracy, robustness, and ability to reject disturbances. MATLAB Simulink simulations confirm the effectiveness of the ISMC under various road conditions, including wet asphalt, snowy, and dry asphalt roads. Additionally, the asymptotic stability of the SBW system is verified using Lyapunov stability theory, ensuring the reliability of the proposed control strategy for modern automotive applications. The simulation results highlight the effectiveness of the proposed ISMC in maintaining precise and robust steering performance across diverse road conditions. The enhanced tracking accuracy, reduced chattering, and improved disturbance rejection capabilities demonstrate its potential for practical application in modern steer-by-wire systems. This study provides a strong foundation for further research and development, paving the way for advanced control strategies in next-generation automotive steering technologies
DESIGN, MODELING AND SIMULATION OF ROBOTIC KRAR STRUMMER FOR ONE-HANDED INDIVIUALS
(Mekelle University, 2025-03-28) ABRAHALEY KAHASY BRHANE
Playing traditional musical instruments, such as the Krar, typically requires two hands, which limits accessibility for individuals with upper-limb disabilities. This thesis addresses this challenge by designing, modeling, and simulating a robotic Krar strummer to assist one-handed individuals in playing the Krar, a traditional string instrument from Ethiopia and Eritrea. Despite advances in assistive technology, few solutions exist for traditional instruments, leaving a gap in accessibility for one-handed musicians. A robotic manipulator was developed to replicate the strumming motion of a human hand, enabling users with one functional hand to engage with the instrument. A three-dimensional model of the robotic strummer mechanism was created using SolidWorks, and its dynamic behavior and control system were simulated in MATLAB/Simulink. Rhythmic trajectories based on traditional Krar performances were analyzed, and a PID controller was implemented to ensure precise strumming patterns. Key findings from the simulations show that the robotic strummer accurately replicates rhythmic patterns with minimal error. The system demonstrated high accuracy in following predefined trajectories, with errors well within acceptable limits set for RKS. Joint space trajectory errors were minimal, with Joint 1 showing a maximum deviation of 0.091 degrees and Joint 2 a maximum deviation of 1.56 degrees without disturbance. With disturbance present, Joint 1 showed a maximum deviation of 1.7 degrees and Joint 2 a maximum deviation of 3 degrees. The controller effectively maintained precise alignment with the desired trajectories, ensuring stable operation. The simulation results under disturbance also demonstrated the system's ability to maintain stability and accuracy, with errors considered insignificant in terms of the rhythmic pattern. This research contributes to enhancing accessibility, enabling one-handed individuals to participate in music creation, promoting inclusivity in musical expression. The detailed design, modeling, and simulation results confirm the feasibility of the proposed robotic Krar strummer system. This research represents a step forward in assistive technology, bridging the gap between traditional music instrument and accessibility for individuals with disabilities.
COMPARATIVE PERFORMANCE ANALYSIS OF LQR, PID, FUZZYPSO AND PSO-PID CONTROLLERS ON QUARTER CAR ACTIVE SUSPENSION SYSTEM
(Mekelle University, 2025-04-05) KOKEB GEBREMEDHIN
The purpose of this study is to evaluate and compare the effectiveness of various control strategies for active suspension. MATLAB/SIMULINK software is used for both the controller design and the quarter vehicle model. The control strategies PID, LQR, PSO-PID, and FUZZY-PSO are employed. The suspension travel response and sprung mass acceleration response two critical parameters for ride comfort and road handling are chosen, examined, and compared between the responses of the active suspension system and the passive suspension system in order to assess the effectiveness of the vehicle's suspension system. The two Key Performance Indicators (𝐾𝑃𝐼𝑀𝐴𝑋 𝑎𝑛𝑑 𝐾𝑃𝐼𝑀𝐴𝑋) are chosen to demonstrate a decrease in peak overshoot and a decrease in oscillation for the parameters chosen for the active and passive suspension system comparison. From this research, in summary, the PSO-PID and FUZZY-PSO controllers that were created exhibit exceptional performance in enhancing ride quality, hence increasing passenger safety and vehicle handling in the presence of two bumpy road disturbances. When it comes to decreasing to sprung mass acceleration and suspension travel, the PSO-tuned fuzzy logic controller performs the best, followed by PSO-PID, LQR, and PID controllers.
DESIGN AND SIMULATION OF SINGLE AXIS SOLAR TRACKER FOR IMPROVING THE EFCIENCY OF PARABOLIC CONCNTRATOR
(Mekelle University, 2025-04-07) Awet Welay Hadgu
This research explores the design, simulation, and analysis of an active single-axis solar tracking system aimed at addressing the challenges associated with optimizing the performance of parabolic solar concentrators. Solar concentrators, particularly parabolic designs, offer significant advantages in harnessing solar energy for thermal applications, yet their efficiency is highly dependent on precise solar tracking. The current study develops a robust system designed to improve tracking accuracy, withstand challenging environmental conditions, and enhance overall system performance. Finite Element Analysis (FEA) was employed to validate the system’s structural reliability under extreme wind speeds of up to 55 m/s, a critical factor for ensuring operational stability in windy regions like Ethiopia. Additionally, dynamic modeling and control system design were carried out using MATLAB/Simulink, where a PID controller was tuned for optimal tracking performance. Results from simulations showed that the system achieved a tracking accuracy of over 96%, with minimal errors even under disturbances. These findings underscore the importance of integrating advanced tracking mechanisms in renewable energy systems to maximize energy capture and utilization. By addressing key challenges identified in existing parabolic concentrators, this study contributes significantly to the body of knowledge on solar energy systems and presents a practical solution for enhancing their efficiency, particularly in resource-constrained settings like Ethiopia
Post-war Risk Assessment and Management in Tigray: case study on Small and Medium Manufacturing Enterprises at Mekelle
(Mekelle University, 2025-04-25) Berihu Teklay
Small and medium manufacturing enterprises are critical to economic back bone of countries, but their mission and objectives is highly affected by war and faced for various risks and challenges. Researchers were finds that the impact or damage assessment of war in small and medium manufacturing enterprises but those studies are insufficient to identify specific post war risks to be face in the sector during post war recovering and how manage the specific risks. This study aims to investigate the post-war risks affecting SMMEs in Tigray and proposes strategies for effective risk management and resiliency. This study employs mixed method approach combination of qualitative and quantitative research design. Data was collected from literatures, government reports and data’s and primary data from survey interviews and questionnaires. The sample size of 90 number of enterprises were selected from the total of 1349 including textiles and garment, manufacturing material manufacturers, metals works and furniture’s, agro processing and chemical packaging’s sectors and 10 SMMEs industry experts and questionnaires was distributed. Qualitative and quantitative data analysis such as interviews, questionaries’ and relative important index was conducted in the study. A total of 32 post-war risks were identified and categorized into seven groups: financial, supply chain, market, human resource, operational, technological, and socio-political. Using statistical tool Relative Importance Index (RII) method, the study prioritized risks based on their likelihood, impact and their risk levels. Findings reveal that limited access to financial loans and supports, supply chain disruptions, increasing overall manufacturing cost and inflations are among the most critical risks to the survival of SMMEs in the region after the war. The study recommends management strategies such as strengthening government support, enhancing human resource development through educational partnerships, promoting market and supply chain diversification, and leveraging automation technologies. These strategies aim to enhance SMMEs’ resilience, support sustainable economic recovery, and contribute to long-term regional development. The research concludes with strategic recommendations and future research studies in investigation interrelationships between identified post-war risk factors, which could provide a deeper insight into how these risks interact and compound each other.
OPTIMIZING BIOMASS COMBUSTION IN INDUSTRIAL BURNERS: A CASE STUDY ON MASS AND ENERGY BALANCE AT MAICHEW PARTICLE BOARD FACTORY
(Mekelle University, 2025-04-28) Haregeweiny Weldu Hailu
The growing need to reduce reliance on fossil fuels has prompted exploration of biomass as a sustainable energy source. Maichew Particle Board Factory, a sister company of EFFORT, producing 3,360 tons of sawdust annually, has untapped potential to utilize biomass for energy generation. This study aims to perform a mass and energy balance analysis on the factory's burner, optimize the air-to-fuel ratio, and identify challenges in transitioning to biomass as the primary fuel. A combustion analysis was conducted using the fuel combustion equation, and optimization of the air-to-fuel ratio was carried out using Microsoft Excel Solver. The analysis revealed that the burner consumes 376.95 kg of sawdust per hour and 6,1 80.9 kg of air per hour, producing 5,791 .5 MJ/hr of flue gas energy for the dryer. The findings underscore the factory's capacity to utilize sawdust effectively as fuel, offering a pathway to reduce fossil fuel dependence and enhance energy efficiency in biomass-based operations.
Experimental Characterization and Finite Element Analysis of Jute and Glass Fiber Reinforced Epoxy Composite Material for Structural Automotive Components.
(Mekelle University, 2025-05-19) Haftom Hailemichael
Using of fiber-reinforced composite materials is rapidly advancing in the automotive and aerospace industries due to their superior properties, including lightweight, high strength-to-weight ratio, high impact strength, corrosion resistance, design flexibility, and dimensional stability. Traditionally, vehicle bodies have been constructed from heavy metals like steel, increasing vehicle weight and fuel consumption. This study focuses on enhancing the mechanical properties of Jute/Glass Fiber reinforced epoxy composites for automotive body applications. The research evaluates tensile, compression, impact, and flexural strengths of unidirectional jute and glass fiber composites by varying fiber weight ratios, orientation angles, and stacking sequences. Experimentation followed ASTM standards, and the composite car bonnet was designed and analyzed using Classical Laminate Theory and optimization via Opti-Struct in Altair Hyper Mesh 2019. Results indicated that a 50/50 weight ratio of jute to glass fibers with unidirectional orientation offered the best mechanical properties. Additionally, incorporating ±45° fiber orientations enhanced impact strength in both lateral and transverse directions. The bonnet design optimization led to a 67% weight reduction compared to conventional steel bumpers, resulting in an average fuel savings of 0.0034 L/100 km. Thermal analysis using FEM Ansys showed that the composite bonnet had lower thermal conductivity and heat flux, with higher temperature distribution at the edges due to constraints. The thermal stress remained within safe limits, indicating no immediate failure risk. In conclusion, the hybrid composite material with Jute/Glass fibers can effectively replace traditional steel Bonnet, offering significant weight reduction and fuel efficiency improvements without compromising safety.
DESIGN, DEVELOPMENT, AND EXPERIMENTAL INVESTIGATION OF A PORTABLE MULTI-BLOCK MAKING MACHINE
(Mekelle University, 2025-05-19) Kibrom Gidey
This thesis presents the design, development, and experimental investigation of a Portable MultiBlock Making Machine, aimed at overcoming the limitations of existing single-block and multiblock machines. The innovative design combines portability with high output efficiency and reduced energy consumption, making it suitable for small to medium-scale manufacturers in diverse construction environments. The developed prototype demonstrates the capability to produce five hollow cement blocks simultaneously, adhering to industry standards for block quality and structural integrity. Finite Element Analysis (FEA) was employed to validate the structural reliability and production efficiency of the machine. Key findings from the FEA indicate that stress distribution, displacement, and strain levels remain well within acceptable limits. The von Mises stress analysis confirms that all components experience stress values significantly below the yield strength of ASTM A36 mild steel, ensuring that the machine operates within the elastic deformation range, thereby preventing permanent failure. Additionally, the displacement analysis reveals minimal deformation across all structural components, indicating robust mechanical stability during operation. The strain analysis further validates effective stress distribution, demonstrating that material selection and design choices mitigate localized strain concentrations, enhancing overall durability. The Factor of Safety (FOS) analysis provides a minimum safety margin of 1.5, reinforcing the design's compliance with industrial safety standards and its ability to withstand operational loads. The successful fabrication and testing of the prototype confirm that the Portable Multi-Block Making Machine offers a high-output, energy-efficient alternative to conventional block-making methods, significantly improving productivity and lowering operational costs. Looking ahead, future enhancements should focus on fatigue analysis, structural reinforcement in high-stress areas, and optimization of mold alignment to further boost efficiency and lifespan. The integration of automated control systems and renewable energy sources could also enhance sustainability and operational flexibility.
Design and Optimization of Bamboo/Glass Fiber Reinforced Epoxy Composites for Sustainable Wall Panel Application
(Mekelle University, 2025-05-19) Amelewerk Halefom
The increasing demand for sustainable construction materials has driven interest in natural fiber reinforced composites as eco-friendly alternatives to conventional materials. This study focuses on the design and optimization of bamboo/glass fiber-reinforced epoxy composites for application in sustainable wall panels, aiming to achieve a balance between mechanical performances, weight reduction, improve water resistance and sustainability. Different stacking sequences (B-G-B, G-B-G, G-G-B, and B-B-B) of bamboo and glass fibers were fabricated using the hand lay-up technique, preparation of 40% fiber and 60% of epoxy matrix incorporating alkali-treated bamboo fibers to improve interfacial bonding. The mechanical and physical properties of the fabricated composites were experimentally determined according to ASTM standards. A multi-criteria decision-making approach, using the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS), was employed to identify the optimal composite configuration. And it tells that G-B-G, characterized by a stacking sequence comprising 30% Bamboo, 10% glass, 60% epoxy, stands out as the optimal choice. The structural behavior of the optimized wall panel design was analyzed using Classical Lamination Theory. The optimization process, incorporating a genetic algorithm in MATLAB, aimed to minimizing weight and the constraint function is Tsai-Wu failure criterion. It results weight of the composite is 23.04kg, which reduced weight of the plywood weight by 15%, gypsum board by 5.8% and concrete panel by 38.4% and brick by 36%. Using literature review optimization, the water absorption of composite is 2.98% which reduced water absorption of the plywood by 7.11% of the gypsum board dry well is 9.11%, and concrete panel 2.11%, brick panel reduce by 8%. The optimized results were validated using ABAQUS of FEA. The maximum stress obtained from Genetic algorithm is 4.466Mpa and the maximum Von Mises stress is 8.511Mpa. The maximum deformation of the composite laminate is 12.2mm. This is less than the ultimate strength, proving the composite wall panel is safe and shows the safety factor is 2.5 against failure. The results of this study contribute to the development of sustainable and high performance wall panels using locally available bamboo resources.
Design and Optimization of a Hybrid Polyester Composite for Bus Roof Plates Using Jute and Reused PET Fiber Reinforcement
(Mekelle University, 2025-05-19) Natnael Abera
The automotive sector faces rising fuel consumption and pollution due to the increasing vehicle numbers. To mitigate these challenges, lightweight materials have become imperative to diminish the weight of automotive components. Additionally, addressing the pervasive issue of plastic pollution necessitates innovative solutions, such as recycling or reusing the primary plastic pollutant, polyethylene terephthalate (PET). This study tackles two interconnected issues: reducing vehicular weight through material substitution and mitigating plastic waste by reusing PET from discarded water bottles. The main objective of this study is to design and optimise a hybrid polyester composite material for bus roof plates for the modified ISUZU NPR71 4570cc, utilizing jute and reused PET fibers as reinforcement. Samples were prepared using the hand lay-up method, with fiber-to-matrix weight fractions ranging from 40% to 60%. Five laminates were created, incorporating alkali-treated jute fibers to enhance interfacial adhesion. Through a series of experimental tests, the tensile, compressive, flexural, impact strengths, density, and water absorption rates were conducted. The TOPSIS method was applied to assess and evaluate the properties of prepared laminate samples. Results indicate that the P-J-J-P orientation of NaOH treated jute fiber stands out as the optimal choice. The NaOH-treated jute fiber reduces water absorption by 47% (1.13% compared to 2.13% for untreated jute). A hybrid composite with a PJ-J-P layup and a 0°-90°-0° orientation was used to design a bus roof plate, optimised using Hyper Works-Optistruct and validated through re-analysis with ABAQUS. The optimised jute/PET hybrid polyester composite roof plate achieved a 34.58% weight reduction compared to a mild steel plate, decreasing from 210.38 kg to 137.63 kg, and saved 0.2765 litres of fuel per 100 km. This demonstrates that jute/PET hybrid polyester composites can effectively replace steel structures, offering significant environmental benefits and fuel savings without compromising performance or vehicle load capacity.
Feasibility Study and Energy Management System of Mini Grid Hybrid Systems for Energy Intensive Industries: A Case Study of Industries in Mekelle
(Mekelle University, 2025-05-30) Hiwot Nigusie
Hybrid systems integrate renewable energy sources with battery storage to supply energy in offgrid or on-grid setups. Many studies on hybrid power generation focus primarily on rural electrification, the socio economic benefits for households and local communities and remote areas, often overlooking the impact on industrial development. This literature gap limits our understanding of how reliable electricity access could drive industrial growth, enhance productivity, and foster economic diversification. This study focused on the techno-economic feasibility of a mini hybrid power generation system for electrification of three energy intensive manufacturing industries that are located in Mekelle city of Tigray namely Mesfin Industrial Engineering, MOHA soft drinks industry, and Desta Alcohol & Liquor Factory. The aim was to study the feasibility of a hybrid renewable energy solution to make industries energy independent and provide sufficient power and tied them with reliable power system by avoiding their grid dependency. The software packages utilized is used to design, analyze, and optimize the hybrid power system were HOMER Pro modeling tool. The mini grid has a peak capacity of 230 kW requires 3005 kWh/day. The Generic PV system has a nominal capacity of 720 kW. The annual production is 1,321,381 kWh per year for Mesfin Industrial Engineering. The electric needs for MOHA soft drinks industry are met with 720 kW of PV, 320 kW of generator capacity, 330 kW of wind generation capacity with operating costs for energy of $388,003 per year without battery storage. An addition of 1,000 kWh of battery capacity is proposed. This will reduce the operating costs to $458,636 per year. A 50 kW of generator capacity, 1,000 kWh of battery capacity and for Desta Alcohol & Liquor Factory 50 kW of wind generation capacity, with operating costs of $154,451 per year. It is proposed that adding 110 kW of hydropower generation capacity would reduce operating costs to $154,421/yr.
Optimization of Supply Chain Management on Financial Performance through Simulation Modeling (A Case Study in Moha Soft Drink Industry, Mekelle)
(Mekelle University, 2025-05-30) Godefa Berhe Weldegebrial
Nowadays, industries are trying to maintain their competitiveness in the market by optimizations of SCM on the financial performance industry using simulation model tools. One of the simulation model tools that help in visualizing the processes required to create a product and deliver it to the final customer. The research purpose was to optimize Supply Chain Management on the financial performance in the Soft drinks industry, Mekelle. This study used a descriptive analysis; it relied on testing the average of four financial metrics for performance: Return on Asset machine, Return on Investment inventory, Return on Equity capital and gross profit Margin sales and the simulation modeling between them prior running the SCM and its validation optimization. The simulation modeling were made between their ten years average values of the system, and optimizations, hybrid analysis used with a quantitative and qualitative approach method secondary data collection instrument of financial ratio from audited financial statements was used. Simple random sampling existing SCM financial performances have been used to optimize the financial. Ten years data (2014-2024) consist of the existing SCM period. A paired t-test hypothesis test was performed on the calculated means at a 95% confidence interval level with the tool Arena version 14 Simulation to determine whether there was a significant the means of the ten periods for each ratio. Means for each recorded ratio was calculated to obtain the existing and optimizations. The study reveals best fit manufacturing 65.27%, which is 8.27% higher than the starting point of 57% of the existing supply chain management that respective each other the existed and significantly optimization of SCM on financial performance. Therefore, the study concluded that SCM was simulation modeling significant with optimizations on financial performance in the MOHA industry. SCM on Financial indicator replication average 60, half width (corresponding p-value) 1.5,minimum average 60.13%, maximum average 69.14%,minimuim value 0.0013,maxium value added 662.88, resource and queue zero there is no delay, utilization value added (VA)6% chi square p-value 0.05 and ks test 0.15 contributing to enhanced financial performance. Overall financial performance optimization using simulation models based on the findings the study recommended that other manufacturing companies can also initiate to use optimization SCM as a sample study area by taking the success of financial performance optimization in MOHA soft drink industry.
Investigation of the Effects and Optimization of Shielded Metal Arc Welding Process Parameters on Mechanical properties of ST37-2 Low Carbon Steel
(Mekelle University, 2025-06-12) Hadera Berhe
Shielded metal arc welding (SMAW) is the most widely used application process in manufacturing industries and maintenance components of low carbon steel (ST37). Due to simplicity, versatility and low price, it has always been the center of concern for industrialists and researchers. However, selection of optimum setting of welding parameters is the vital in achieving high performance of the welded joints. In this study, welding process parameters are the main factors that affect the quality of welded joints. This study aims to enhance the quality of the welding joints in industrial applications made from low carbon steel (ST37-2) by optimizing the welding parameters for SMAW. Current, electrode diameter and thickness of material were selected as input parameters of the study. SMAW welding has been carried out as per L9 orthogonal design considering an orthogonal array consists of three factors and three levels. The mechanical properties of the weld joint have been assessed in terms of ultimate tensile strength and yield strength of the fusion zone in the study. Grey relational analysis (GRA) based on Taguchi has been used to optimize the process parameters. ANOVA approach was performed to determine the effect (significant) of the SMAW parameters and optimal of the parameters using Minitab 20 software. The thickness of material was the most important parameter, followed by electrode diameter and current according to the ANOVA result with grey based Taguchi optimization methods (81.92%, 14.61% &2.82% respectively). The confirmatory test was conducted to verify the optimization process, which proved the grey-based Taguchi method to be easy and effective method for multi objective optimization of welded joints. The confirmation test revealed that the Taguchi grey relational analysis (GRA) methods of optimal SMAW process parameters increased the ultimate tensile strength and yield strength of the joints. The experimental outcome also demonstrated the viability of the Taguchi-based GRA approach for resolving multi-response optimization issues in the SMAW process. The error between the experimental and predication values for GRG is within the range. The validation outcomes obtained shows that the optimization technique is reliable tool for improving the quality responses of shielded metal arc welding. Clearly, this confirms good experimental and reproducibility of conclusion