Blar i UiS Brage på forfatter "Lemu, Hirpa G."
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Non-linear buckling analysis of ship hull stiffened panels
Hacihamud, Enes; Dahl, K; Gabrielsen, O.; Lemu, Hirpa G.; Siriwardane, Sudath C. (Peer reviewed; Journal article, 2023)Stiffened panels are crucial in maritime applications, where buckling is a primary structural failure concern. Typically, assessing the buckling capacity of these panels relies on established guidelines like DNV-RP-C201 ... -
A Novel Technique for Temporarily Repair and Improvement of Damaged Pin Joint Support Bores
Karlsen, Øyvind; Lemu, Hirpa G.; Berkani, Imad (Peer reviewed; Journal article, 2022)Damaged support bores due to wear and ovality can be critical for a machine and its operation, in addition to representing a safety problem and risk of pin breakage. It can be a costly operation to perform the required ... -
Numerical analysis of the influence of friction conditions on the pile-up effect in Vickers hardness measurements
Trzepiecinski, Thomasz; Lemu, Hirpa G. (Peer reviewed; Journal article, 2019)Vickers indentation load-depth curve may be used to determine basic mechanical properties of metallic materials such as hardness, yield stress, modulus of elasticity, and elastic and plastic work. The pile-up phenomenon ... -
Numerical Simulation and Customized DACM Based Design Optimization
Woldemariam, Endashaw Tesfaye (PhD thesis UiS;, Doctoral thesis, 2018)The diverse numerical modelling, analysis and simulation tools that have been developed and introduced to markets are intended to perform the virtual design and testing of products and systems without the construction of ... -
Numerical simulation of FDM manufactured parts by adopting approaches in composite material simulation
Akessa, Adugna Deressa; Gebisa, Aboma Wagari; Lemu, Hirpa G. (Peer reviewed; Journal article, 2019-11)Additive manufacturing (AM) process is a promising manufacturing method that can replace conventional manufacturing methods, particularly for parts with complex geometry. It is the process of joining materials layer by ... -
Numerical simulation-based effect characterization and design Optimization of micro cross-flow turbine
Woldemariam, Endashaw Tesfaye; Lemu, Hirpa G. (Peer reviewed; Journal article, 2019)In this era of high power demand along with a need for sustainability, small and micro-scale hydro turbines are indispensable, especially for off-grid power generation. These hydro-turbines are more appealing, particularly ... -
On Competition-driven Teaching of Multidisciplinary Engineering Education: Implementation cases at University of Stavanger
Lemu, Hirpa G. (Peer reviewed; Journal article, 2017)This article will reflect the experience gained on problem-based learning (PBL) projects implemented in the last six years at University of Stavanger (UiS). The PBL projects were implemented by establishing two ”student-driven” ... -
Overview study on challenges of additive manufacturing for a healthcare application
Wakjira, Yosef Adugna; Lemu, Hirpa G.; Akessa, Adugna Deressa (Peer reviewed; Journal article, 2021)Additive manufacturing is a rapidly evolving manufacturing technology bringing numerous and wide opportunities for the design team involved in the process by creating intricate and customized products with saving labor, ... -
Prediction of Fatigue Crack Initiation under Variable Amplitude Loading: Literature Review
Kedir, Yahiya Ahmed; Lemu, Hirpa G. (Peer reviewed; Journal article, 2023)Metallic materials are widely employed in engineering constructions, and one of the most common failure mechanisms in metals is fatigue failure. Even though metal fatigue has been studied for almost 160 years, many problems ... -
Prediction of springback in the air V-bending of metallic sheets
Trzepiecinski, Thomasz; Lemu, Hirpa G. (Peer reviewed; Journal article, 2019)Springback is a critical phenomenon in design and analysis of sheet metal forming process of metallic sheets. An accurate prediction of elastic recovery of material allows to design forming tools which take into account ... -
Process parameter modelling and optimization techniques applied to fused deposition modelling: A review
Batu, Temesgen; Lemu, Hirpa G.; Shimels, H.G.; Zebenay, M. (Peer reviewed; Journal article, 2023)Manufacturing is the foundation of any industrialized country and involves making products from raw materials using various processes. Additive manufacturing (AM) was originally created as a method for swift prototyping, ... -
Produktutvikling og Konstruering av ROV Ramme og Float med Hensyn på Design for Miljø konseptet
Nordal, Christine; Nygård, Sandra (Bachelor thesis, 2022)Denne oppgåva har som mål å designa og konstruera ramma til ROVen, kalla Fenris, og den indre og ytre konstruksjonen av flytaren, kalla Frøya, ved å følgja produktutviklingsprosessen (PUP). Dette inkluderer utviklinga av ... -
Produktutvikling og konstruering av ROV ramme og flyter med omsyn til design for miljø konseptet
Nordal, Christine; Nygård, Sandra (Bachelor thesis, 2022)Denne oppgåva har som mål å designa og konstruera ramma til ROVen, kalla Fenris, og den indre og ytre konstruksjonen av flytaren, kalla Frøya, ved å følgja produktutviklingsprosessen (PUP). Dette inkluderer utviklinga av ... -
Property characterization of acacia tortilis for natural fiber reinforced polymer composite
Dawit, Jonathan B.; Regassa, Yohannes; Lemu, Hirpa G. (Peer reviewed; Journal article, 2019-12)Eco-friendliness and availability of green fiber reinforced based composites attracted many as a potential replacement for non-biodegradable synthetic fiber. Green composites are biodegradable and less susceptible to health ... -
Recent developments and trends in the friction testing for conventional sheet metal forming and incremental sheet forming
Trzepiecinski, Thomasz; Lemu, Hirpa G. (Peer reviewed; Journal article, 2020)Friction is the main phenomenon that has a huge influence on the flow behavior of deformed material in sheet metal forming operations. Sheet metal forming methods are one of the most popular processes of obtaining finished ... -
Review and synthesis of a walking machine (Robot) leg mechanism
Terefe, Tesfaye Olana; Lemu, Hirpa G.; K/Mariam, Addisu (Peer reviewed; Journal article, 2019-08)A walking machine (robot) is a type of locomotion that operates by means of legs and/or wheels on rough terrain or flat surface. The performance of legged machines is greater than wheeled or tracked walking machines on an ... -
Review on fatigue life assessment methods for welded joints in orthotropic steel decks of long-span bridges
Villoria, Bruno; Siriwardane, Sudath C.; Lemu, Hirpa G. (Peer reviewed; Journal article, 2021)Orthotropic Steel Decks have been used in long-span bridges for several decades because of their high capacity to weight ratio. However, many fatigue related issues have been reported. This paper provides an overview of ... -
Safety related study of Expanding Pin systems application in lifting and drilling equipment within Construction, Offshore, and Marine sectors
Karlsen, Øyvind; Lemu, Hirpa G. (Peer reviewed; Journal article, 2021)A questionnaire-based survey has been performed among original equipment manufacturers (OEMs), sub-suppliers, engineering companies, end-users, service & maintenance, and “others”, as part of an investigation to clarify ... -
State-of-the-art of crack propagation modelling in tubular joints
Atteya, Mostafa Ahmed; Mikkelsen, Ove; Lemu, Hirpa G. (Peer reviewed; Journal article, 2019)Offshore structures are conventionally designed for a service life between 20-30 years and mostly used beyond their service life. They are operated up to the point where costs of operations, maintenance and repair exceed ... -
Study of Bondura® Expanding PIN System – Combined Axial and Radial Locking System
Akhtar, Muhammad Maaz; Karlsen, Øyvind; Lemu, Hirpa G. (Peer reviewed; Journal article, 2021)Bolted connections are widely used in parallel plates and flanged joints to axially lock using the preload generated by the tightening torque and to constrain radial movements of the flanges by the surface friction between ...