Blar i UiS Brage på forfatter "Lemu, Hirpa Gelgele"
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Analysis of Thermomechanical Cracks of Disc Brake Used in Heavy Trucks
Bena, Welteji; Lemu, Hirpa Gelgele (Peer reviewed; Journal article, 2022)In the present work, the study of fatigue failure of the disc brake of Volvo truck under thermomechanical effects across the disc thickness is reported. Both analytical and numerical approaches have been used. In the ... -
A case study on use of 3D scanning for reverse engineering and quality control
Lemu, Hirpa Gelgele; Helle, Robin H. (Peer reviewed; Journal article, 2021-03)Reverse engineering is needed to acquire knowledge of design that is lost, obsolete or withheld. Techniques have evolved from manual measurements, to utilizing the possibilities that lie within 3D scanning technologies. ... -
Comparative study on loosening of anti-loosening bolt and standard bolt system
Karlsen, Øyvind; Lemu, Hirpa Gelgele (Peer reviewed; Journal article, 2022)In general, bolted connections are exposed to vibrations or repeated over-loads that could lead to self-loosening due to loss of preload. Pre-tensioned bolts in ring flanges are critical parts in Offshore Floating Wind ... -
Composite Overwrapped Pressure Vessel Design Optimization Using Numerical Method
Regassa, Yohannes; Gari, Jema; Lemu, Hirpa Gelgele (Journal article; Peer reviewed, 2022-08-05)Composite Overwrapped Pressure Vessels (COPVs) are widely used in fields including aeronautics and by companies such as SpaceX to hold high pressure fluids. They are favored for these applications because they are far ... -
Conceptual Design and Feasibility Study for a Generic Connector for Subsea Fluid Transfer
Helle, Robin Heimli (Master thesis, 2021)Hot stabs are connectors for subsea fluid transfer between Remote Operated Vehicle (ROV) power sources and subsea equipment. Current hot stab solutions, that are compliant with industry standards, have significant limitations ... -
Contact temperature analysis of the classical Geneva mechanism through numerical methods
Ambaye, Getachew A.; Lemu, Hirpa Gelgele; Tolcha, Mesay A. (Peer reviewed; Journal article, 2022)In this study, the flash temperature of the classical Geneva mechanism has been studied using the numer- ical method. An excessive sliding motion between the wheel and pin leads to the generation of heat at the contact ... -
Current Concepts for Cutting Metal-Based and Polymer-Based Composite Materials
Trzepieciński, Tomasz; Najm, Sherwan Mohammed; Lemu, Hirpa Gelgele (Peer reviewed; Journal article, 2022)Due to the variety of properties of the composites produced, determining the choice of the appropriate cutting technique is demanding. Therefore, it is necessary to know the problems associated with cutting operations, ... -
Design and control of ROV manipulators
Merenyi, Joachim Skjervik; Fjermedal, Sindre (Bachelor thesis, 2021)This thesis is about the design and production of a manipulator for a ROV for the student driven company UiS Subsea. The ROV will be used in the MATE ROV competition. The design and mechanisms were chosen based on weight ... -
Design and control of ROV manipulators
Fjermedal, Sindre; Merenyi, Joachim Skjervik (Bachelor thesis, 2021)This thesis is about the design and production of a manipulator for a ROV for the student driven company UiS Subsea. The ROV will be used in the MATE ROV competition. The design and mechanisms were chosen based on weight ... -
Determining Optimum Rotary Blade Design for Wind-Powered Water-Pumping Systems for Local Selected Sites
Mohammed, Abdulbasit; Lemu, Hirpa Gelgele; Sirahbizu, Belete (Peer reviewed; Journal article, 2021)The design of a windmill rotor is critical for harnessing wind energy. In this work, a study is conducted to optimize the design and performance of a rotor blade that is suitable for low wind conditions. The windmills’ ... -
Dynamic analysis of spur gear with backlash using ADAMS
Ambaye, Getachew A.; Lemu, Hirpa Gelgele (Peer reviewed; Journal article, 2020)Gear tooth profile can deviate from its initial design shape and size as a result of increasing service time under time-varying load, introducing external agents like debris, overheating due to friction, wear, and in ... -
Effect and consequence analysis of expanding PIN-technology in various types of heavy machinery
Karlsen, Øyvind (PhD thesis UiS;, Doctoral thesis, 2023)Expanding pin systems can be applied in any joint, moveable, or fixed, in any type of machine, crane, or equipment, in almost any type of industry, globally. There are a variety of different versions of expanding pins ... -
Expanding PIN system – Combined radial and axial locking system
Akhtar, Muhammad Maaz (Masteroppgave/UIS-TN-IMBM/2020;, Master thesis, 2020-07-15)In the side by side plate joints or flange joints, the standard practice is to have a bolted connection that provides the axial clamping load as well as, avoiding any radial or rotational movement. This can be problematic ... -
Experience in Use of 3D Printing in Engineering Education at University of Stavanger
Lemu, Hirpa Gelgele; Mikkelsen, Ove (Peer reviewed; Journal article, 2021)This article is based on a project run in 2018 and 2019 entitled “Educating Mechanical Engineering using 3D Printing – Under3DP”. The project was funded by Faculty of Science and Technology, University of Stavanger (UiS). ... -
Experimental Investigation and Prediction of Mechanical Properties in a Fused Deposition Modeling Process
Tura, Amanuel; Lemu, Hirpa Gelgele; Mamo, Hanna (Journal article; Peer reviewed, 2022-06-15)Additive manufacturing, also known as three-dimensional printing, is a computer-controlled advanced manufacturing process that produces three-dimensional items by depositing materials directly from a computer-aided design ... -
Experimental Investigation of Al-CuMgMn Alloy Developed by Laser Beam Surface Modification for Wear Resistance
Tolcha, Mesay A.; Jiru, Moera G.; Lemu, Hirpa Gelgele (Peer reviewed; Journal article, 2021-04)Laser surface alloying is one of the recent technologies used in the manufacturing sector for improving the surface properties of metals. Aluminum alloys are key materials in the manufacturing sector. This favors their ... -
Exploration of Mechanical Properties of Enset–Sisal Hybrid Polymer Composite
Bekele, Abera E.; Lemu, Hirpa Gelgele; Jiru, Moera G. (Peer reviewed; Journal article, 2022-02)Enset and sisal fibers are among the most widely used reinforcement to fabricate natural fiber-based composite materials. Hand lay-up techniques were employed in this study to fabricate enset–sisal (E/S) hybrid fiber ... -
Internal Corrosion Damage Mechanisms of the Underground Water Pipelines
Yeshanew, Desalegn A.; Jiru, Moera G.; Lemu, Hirpa Gelgele; Tolcha, Mesay A. (Peer reviewed; Journal article, 2022)Internal water pipe corrosion is a complicated problem due to the interaction of water quality parameters with pipe wall. This study presents investigations of internal pipe surface corrosion mechanisms related to water ... -
Investigation of mechanical properties of false banana/glass fiber reinforced hybrid composite materials
Batu, Temesgen; Lemu, Hirpa Gelgele (Peer reviewed; Journal article, 2020)The objective of the work presented in this article is to investigate the mechanical properties of false banana/glass fiber reinforced hybrid composite materials at different fiber volume fractions and orientation of hybrid ... -
Investigation of the mechanical properties of Acacia tortilis fiber reinforced natural composite
Dawit, Jonathan B.; Lemu, Hirpa Gelgele; Regassa, Yohannes; Akessa, Adugna Deressa (Peer reviewed; Journal article, 2020-10)The work presented in this paper is motivated by the fact that use of natural fiber materials for structural and non-structural applications have increased within the last two decades. In addition to the known benefits of ...