2022 Cilt 27 Sayı 3

Permanent URI for this collectionhttps://hdl.handle.net/11452/30951

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Now showing 1 - 9 of 9

Comparative study for BIM-based LEED industrial building and non-LEED industrial building
(Bursa Uludağ Üniversitesi, 2022-11-02) Seyis, Senem
This study intends to do architectural and structural designs of a sustainable industrial building using BIM and LEED as well as compare the LEED industrial building and non-LEED industrial building. In this scope, the additional costs related to water and energy efficient systems were analyzed to calculate the respective break-even points. Literature review and case study were performed to achieve the research objective. In the case study, a reinforced concrete industrial building was designed via Autodesk Revit 2021 considering the selected sustainability criteria under the LEED v4.1 BD+C for New Construction rating system. The LEED industrial building can fulfill 31 credits and 8 prerequisites which allow to obtain 73 points and LEED Gold certificate. The initial cost of LEED industrial building is 154.222.607 TL while the initial cost of non-LEED industrial building is 139.080.060 TL. Break-even point for the cost of energy-efficient systems utilized in the LEED industrial building is 14 years. Breakeven point for the cost of water-efficient systems utilized in the LEED industrial building is 8 years. Results contribute to the architecture, engineering and construction industry and literature by providing constructive information about the design requirements and energy, water, and cost performance of the LEED industrial buildings.
Developing a motion mechanism for a single module in a self-reconfigurable modular microrobotics system by using external magnetic actuators
(Bursa Uludağ Üniversitesi, 2022-11-10) Dokuyucu, Halil İbrahim; Özmen, Nurhan Gürsel; Çora, Ömer Necati
In microrobotics field, self-reconfigurable modular robots (SRMRs) offer several advantages including adaptation to uneven environments, the capability of handling various sets of tasks, and continuous operation in the case of a malfunction of a single module. The current research direction in self-reconfigurable robotic systems is towards reaching million level number of modules working in coherence by means of locomotion, self-reconfiguration, and information flow. This research direction comes with new challenges such as miniaturizing the modules. One should consider looking for alternative ways of locomotion and self-reconfiguration when dealing with SRMRs having million level number of modules. Externally actuating the modules can be a good alternative to micro SRMRs. In this study, we developed a novel motion mechanism for a single module in a micro SRMR system by using external magnetic actuators. An assembly of elastic microtubes and permanent magnets is attached inside a cube-shaped module and periodic motion of the assembly is applied. The motion of a single microtube with permanent magnets inside is generated by using COMSOL Multiphysics software. The results of the simulations are compared with theoretical values to validate the motion mechanism that is introduced in the study.
Dynamic modeling and control of an electromechanical fin loading system
(Bursa Uludağ Üniversitesi, 2022-09-01) Özkan, Bülent
In this study, the design of an electro-mechanical fin loading system which is utilized to simulate the effects of the aerodynamic moment occurring in an atmospheric flight on a missile system is dealt with. In this extent, the dynamic modeling of the dedicated loading system is constructed and then the control system is designed on that model. As the control algorithm, the classical control system operating with regard of the PID (proportional plus integral plus derivative) control action and the robust control system designed according to the H∞ norm are taken into consideration. Once the mentioned control systems are built, the relevant computer simulations are performed with the inclusion of a realistic control actuation system model in accordance with the consistent numerical values of the necessary parameters. As a result of this work, it is observed that the robust control system yields more satisfactory results than its classical counterpart even under more severe conditions.
Experimental investigation of crush energy absorption and strength properties of sandwich plates with aluminum facesheet/expanded polypropylene foam core
(Bursa Uludağ Üniversitesi, 2022-10-05) Türkoğlu, İbrahim Kürşad
Due to the developing electric vehicle industry in the last decade, weight reduction studies on vehicle bodies have gained great importance. Foam core sandwich structures stand out as the most ideal materials in terms of providing both weight reduction and strength conditions in the bodies of electric individual and public transportation vehicles. In this study, EPP foams with two different densities were placed between aluminum plates and sandwich structures were obtained by combining the two structures with an EVA-based adhesive. Compression and bending behaviors of the produced sandwich structures were investigated under quasi-static and dynamic loading conditions. With the tests carried out, the strength of the sandwich structures and the amount of energy they absorb were calculated and compared experimentally. According to the results obtained, it was observed that the denser D2 foam exhibited approximately 1.4 to 2.05 times more strength than the lower density D1 foam in all tests. In terms of the energy they absorb, the D2 foam absorbs 1.25 to 2.5 times more energy than the other foam. Contrary to this situation, only the dynamic compression test occurred in the tests performed. When the post-damage behavior of the sandwich structures was examined, it was also observed that the D2 foam returned to a very similar dimensions to its original size, giving more of the deformation after the damage at the end of 72 hours.
Heat input effect of the FCAW process on the microstructure and mechanical properties of structural steel joints
(Bursa Uludağ Üniversitesi, 2022-12-09) Gürol, Uğur
Flux-cored wires are commonly used in structural and pipeline welding, shipbuilding, offshore constructions, and petrochemical and power generation industries. The higher heat inputs in the multipass welding result in shorter production time while considerably changing the properties of the welded joint. In this study, robotic flux cored arc welding with varying heat inputs (between 0.56-2.52 kJ/mm) was performed to determine the effect of heat input on weld microstructure, hardness, tensile properties, and impact toughness in the structural steel joints. Results exhibited that decrease in heat input from 2.52 to 0.56 kJ/mm changed the majority of the microstructure from polygonal ferrite to acicular ferrite. Furthermore, this increased by 56%, 37%, and 47% in yield strength, tensile strength, and hardness values, respectively, while decreasing by 30% and 15% in elongation and Charpy impact test results, respectively. Moreover, all welded joints displayed a satisfying toughness value higher than the requested value of 47 J, even at the test temperature of -50 °C. Finally, it can be concluded that the optimum results were obtained with a heat input of 1.26 kJ/mm, considering the minimum requirements of the AWS A5.20 standard and the expectations in applications.
Impact of covid-19 lockdown precautions on air pollutants in Turkey
(Bursa Uludağ Üniversitesi, 2022-08-29) Durak, Sevgi Güneş
Due to the COVID-19 pandemic, the precautions taken in the early period of the pandemic have had a significant impact on the reduction of air pollutants. In this research, the changes in the concentrations of some air pollutants (PM10, NO2, SO2, CO, O3) concentrations have been investigated and evaluated between March 15 - May 31, 2019 and March 15 - May 31, 2020 in Turkey. According to the results, PM10, NO2 and SO2 concentrations decreased by up to 75%, 80% and 77% respectively. However, there has been an increase in CO and O3 concentrations in many cities. Pearson’s correlation analysis showed that there is a strong relevance between NO2 - CO and O3 - CO concentrations in the lockdown period. In addition, with the precautions, the positive correlation between PM10 and NO2 and between SO2 and CO increased, and the negative correlation between PM10 and O3 decreased.
Mechanics of a hyperelastic inflated tube with emphasis on biological soft tissues
(Bursa Uludağ Üniversitesi, 2022-11-10) Büyükkaya, Ömer Faruk; Okyar, Ali Fethi
Inflated hollow cylinder is an important problem encountered in a variety of fields in engineering. In industry, tires and fire hoses are pressurized from inside. In biomechanics, veins, arteries and intervertebral discs can also be modeled using the inflated cylinder problem. The soft ground substance of biological tissues in question are incompressible and portray large non-linear deformations under loading. Classical theories of linear elasticity are incapable of modeling such behavior. Instead, continuum mechanics based large displacement formulation and hyperelasticity are necessary to understand the deformation and mechanics of soft materials. In this study, inflation of a cylinder composed of an isotropic neo-Hookean type of material is analyzed in plane strain and generalized plane strain conditions. First, an analytical solution is established using a continuum mechanical framework. Second, the finite element method is employed to model the same problem. The numerical approach is verified by using a mesh sensitivity analysis and validated by using analytical solution. Therefore, the proposed analytical benchmark can quantify the accuracy of any commercial finite element software solution of neo-Hookean tube inflation. As a side result, it was also revealed that the hydrostatic pressure in the tube is more than six times the inflation pressure.
Optimum design of thermo-plunger support in commercial vehicles by using structural design and finite element methods
(Bursa Uludağ Üniversitesi, 2022-11-28) Kılıçarpa, Ulaş Aytaç; Yıldız, Betül Sultan; Yıldız, Ali Rıza; Bursa Uludağ Üniversitesi/Mühendislik Fakültesi/Makine Mühendisliği Bölümü.; 0000-0002-7493-2068; 0000-0003-1790-6987
This paper focuses on creating an optimum design and development of thermo-plunger parts for commercial vehicles in order to save material, reduce mass and make more sustainable automobiles. In this paper, natural frequency analysis, topology, and topography optimization methods have been used to create a new design for the thermo-plunger part. Thermo-plunger means an electric heater that is used for heating the inside of automobiles effectively and quickly and providing customer thermal comfort. It is positioned in the vehicle body, and its support parts have been developed by structural optimization techniques because there is not enough space in the engine compartment for automatic transmission commercial vehicles. The aim of this study is to make a lightweight and reinforced thermo-plunger support part design. Initially, a draft design was created in 3D model software. After that, topology and topography optimizations were applied on this draft design. At the end of studies, a final optimum support design has been obtained. The final design is 41.1% lighter than the initial design. At the same time, above 50 Hz natural frequency value has been obtained on the final design to avoid resonance problems.
Production and characterization of nanocomposites with graphene and graphene oxide
(Bursa Uludağ Üniversitesi, 2022-12-06) Koçyiğit, Nihayet
The aim of this study was to i.) obtain Graphene (G)/epoxy, Graphene Oxide (GO)/epoxy, G/carbon fiber reinforced plastic (CFRP), GO/CFRP nanocomposites by G and GO addition to epoxy and CF matrices and ii.) investigate the effect of G and GO addition on tensile strength of the nanocomposites produced. The graphene was not homogeneously distributed in polymer matrices; therefore, the G was converted into the GO using hummers method. The characterization GO was carried out by SEM, EDX, FTIR and X-RD analysis, which confirmed the successful production of the GO. The G/epoxy, GO/epoxy, G/CFRP and GO/CFRP nanocomposites were obtained by adding G and GO to epoxy and CF at a rate of 0.1, 0.2, and 0.3%. The effect of G and GO on tensile strength of the nanocomposites was determined using a tensile test. The addition of G and GO at 0.2% rate yielded the best results. The effect of GO on tensile strength was better compared to that of the G.

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