Person: Gültekin, Erol
Loading...
Email Address
Birth Date
Research Projects
Organizational Units
Job Title
Dr. Öğr. Üyesi
Last Name
Gültekin
First Name
Erol
Name
Erol GÜLTEKİN
4 results
Search Results
Now showing 1 - 4 of 4
Publication A Study About Shape and Topology Optimizations on A Connecting Rod(International Journal of Automotive Science and Technology, 2021-06-30) Mehmet YAHŞİ; Gültekin, ErolInternal combustion engines have progressed since they undertook a crucial role to convert chemical energy of fuel to mechanical energy with the reciprocat-ing motion of the piston. Structural elements performed a role under heavy con-ditions with their facing dynamic stresses especially on the connecting rod with compression and tensile stresses. To overcome these stresses, manufacturing methods and design of the connecting rod have studied by the engineers for the different size and types of the engines so far. Many software are interested in structural optimization due to the demand of the field and present means on the application of finite element methods. Instead of focusing on kinetics of the con-necting rod, this study, first, introduces design steps and optimization methods. Then, limitations were determined for a connecting rod, which had critical im-portance in a novel rhombic drive internal combustion engine (ICE). Shape and topology optimizations were used for the ICE part to reduce mass while keeping endurance limit of the structure. In the analyses, Hypermesh, Optistruct and Hy-perView tools of the HyperWorks were used. 50% mass reduction as a constraint was accomplished while the critical compression stress was increased only 26%, which was under the demanded limit of 320 MPa in topology optimization. In the shape optimization, maximum stress was increased to 304 MPa from 191 MPa while 20% mass reduction obtained. The results were compared with the former data.Publication Dynamic compression and impact analyses of the lattice structures for battery safety(SAGE Publications, 2022-12-27) Mehmet Yahşi; Gültekin, ErolIn this study, a battery pack consisting of 18650-lithium-ion cells and battery housing was designed considering lattice structures instead of the plain sheet to improve crashworthiness. The behavior of lattice structures, including a novel design, cross semicircle, semicircle lattices, and topology-optimized model, in total seven different lattice models in dynamic compression and impact loading were examined. Displacement, energy absorption, and specific energy absorption values were compared with the 1.5 mm thick plain sheet model, which is common in the market. In the dynamic compression loading, honeycomb, and plain sheet models absorb more energy with the value of 97.34, and 88.67 J, respectively. Specific energy absorption is best for the plain sheet with the value of 3122.05 J/g, but honeycomb and cross semicircle lattices still have an impressive result of 2923.04, and 2158.30 J/g respectively. On the other hand, in the impact loading, the plain sheet is causing the jellyroll deformation with the highest value of 141.65 MPa, while the best protective structure is 3D kagome with a value of 4.85 MPa. However, the cross-semicircle keeps an average safety performance for both loading conditions.Publication Experimental investigation of trimethyl borate as a fuel additive for a SI engine(Informa UK Limited, 2023-01-25) Alper Calam; Mükerrem Şahin; Gültekin, ErolPublication Investigation of Lattice Structures for the Battery Pack Protection(2021) Erol Gültekin Mehmet Yahşi; Gültekin, Erol; Türk Hava Kurumu Üniversitesi, Mühendislik Fakültesi, Makine Mühendisliği Bölümü, Ankara, Türkiye Bursa Uludağ Üniversitesi, Mühendislik Fakültesi, Makine Mühendisliği Bölümü, Bursa, TürkiyeTransportation market once more put emphasis on electrical and hybrid vehicles to satisfy environmental regulations and disregard fossil fuel price variations. Leading companies in the market and the researchers study on critical units of electrical and hybrid vehicles such as electric motors and batteries which directly affect the vehicle performance on different operating modes. However, battery safety on unusual cases such as crash, explosion or fire caused by the short cut inside the battery pack could damage the other units and the human inside or around the vehicle. On that point, generally, protection of the battery system accomplished by the battery housing with the usage of steel or aluminum sheets. In this study, battery housing designed with sandwich panels constructed with different lattice structures, which could be used in aviation, aerospace, manufacturing industries and biomechanical applications. High strength and stiffness, thermal flow and mass reduction opportunities makes the lat-tices foremost solution when compared with plain sheet metals. In this scope, the lat-tice structures were introduced and six different lattice types designed in Solidworks and analyzed in HyperWorks from the point of static loading with 0.2 MPa on upper cover while keeping the lower one fix. Compliance value evaluated for each lattice structure to find linear static response when loaded. Results show that hexagonal honeycomb lattice have superiority on other structures regarding to the compliance value noted as 3.82 Nmm for the load case while 23% mass increase according to plain sheet metal. For the mass reduction output, cross semicirlcle and 3D kagome lattices presents superiority.