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Öğe Analysis of an actively controlled composite box manipulator without external actuator(Sage Publications Ltd, 2024) Lok, Sefika, I; Malgaca, Levent; Uyar, MehmetThis study focuses on active vibration control for a single-link composite box manipulator by using a single actuator for driving and control actions. Model extraction and system identification techniques are studied to obtain mathematical models of the manipulator. The state space model is extracted from the finite element model using modal analysis conducted in ANSYS, while the system identification approach is an experimental modeling method using the input and output signals of the system. The input signals are defined as triangular and trapezoidal motion profiles, while the output signals are the acceleration signals of the manipulator. Proportional derivative and positive position feedback controllers are implemented on the obtained mathematical models to reduce residual vibrations. The simulation results are successfully verified by experiments, and uncontrolled/controlled results are evaluated with reduction rates.Öğe Enhanced thermal and angular velocity-induced hybrid piezoelectric energy harvesting of smart turbine blades(Elsevier, 2024) Uyar, MehmetIn this study, an approach is proposed to examine hybrid piezoelectric energy harvesting performances from vibrations induced by thermal and angular velocity loads in order to generate energy from the smart turbine blade. In the proposed method, a smart turbine blade is formed by patching the piezoelectric material to the root surface of the turbine blade. A finite element (FE) model of the smart turbine blade is established and then it is validated with a smart blade model in a reference study to test the reliability and accuracy of the FE method. The defined loads are applied to the smart blade to obtain energy from mechanical vibrations induced by thermal and angular velocity loads. Temperature distribution, voltage, and vibration results obtained from energy harvesting analysis under different thermal and angular velocity loads are presented. In order to investigate the energy conversion efficiency of the energy obtained from the system, the energy harvesting circuit is tested in terms of battery discharge times and power output values. The results show that while the maximum energy conversion in the thermally induced smart turbine blade is 11.9 W, a power output of 12.3 W is obtained from the hybrid energy harvesting mechanism under angular velocity and heat flux loads.Öğe Eşdeğer Kütle-Yay-Sönüm Elemanı Kullanılan Ankastre Kompozit Bir Kirişin Titreşim Analizi(2018) Yavuz, Şahin; Uyar, Mehmet; Malgaca, Levent; Karagülle, HiraKompozit malzemeler hafif ve dayanıklı oldukları için manipülatör olarak endüstriyel yapılarda yaygın olarak kullanılmaktadır. Bu çalışmada, [0/90] oryantasyona sahip ankastre kompozit bir kirişin titreşim analizi çalışılmıştır. Yapının ucuna kütle eklenmiştir. Başlangıç koşulu olarak deplasman uç noktaya uygulanmış ve deneysel sistemin serbest titreşimi elde edilmiştir. Eksponansiyel sönüm bulunmuştur. Titreşim sinyalinin Hızlı Fourier dönüşümü kullanılarak doğal frekanslar hesaplanmıştır. Sistem ANSYS programında analiz edilmiş ve simülasyon sonuçları elde edilmiştir. Sönüm katsayısı, deneyden elde edilen eksponansiyel sönümden yararlanılarak hesaplanmıştır. Deneysel ya da simülasyondan elde edilen statik çökme, doğal frekans ve eksponansiyel sönüm kullanılarak sistemin eşdeğer kütle-yay-sönüm elemanı oluşturulmuştur. Eşdeğer kütle-yay-sönüm elemanı sonuçları Laplace dönüşüm metodu ile elde edilmiştir. Deneysel, simülasyon ve analitik sonuçlar uç noktanın farklı başlangıç yer değiştirme değerleri için karşılaştırılmıştır. Sonuçların uyumluluğu gözlemlenmiştirÖğe Experimental Active Vibration Control of a Highly Flexible Composite Manipulator with Acceleration Feedback(Springer Science and Business Media Deutschland GmbH, 2022) Uyar, Mehmet; Malgaca, Levent; Lök, Ş.İpek; Can, Seda VatanIn this study, vibration control of a single-link flexible smart composite manipulator (FSCM) is experimentally studied. The experimental system includes a real-time data acquisition control card, accelerometer, amplifier, servo motor, and driver. The FSCM is an epoxy-glass composite manipulator with the piezoelectric actuator and has the orientation of [0/90] lay-up. Modal analysis is experimentally conducted to find the natural frequencies by applying a chirp signal to the piezoelectric actuator. Natural frequencies are found by taking the Fast Fourier Transform (FFT) in MATLAB. Triangular motion profiles are used to drive the FSCM. Motion parameters are found by utilizing the natural frequencies of the system for different deceleration times (tdec). with different deceleration times (tdec). Residual vibrations are suppressed by using PID control with acceleration feedback. The acceleration signals at the tip point are measured by utilizing the accelerometer. The controller gains are determined with the trial and error method. Experimental residual vibration results are presented for the active control. It is observed that the suppression of vibration amplitudes further increases with active control. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.Öğe Farklı Karakteristikli Piezoelektrik Algılayıcıların Dinamik Performanslarının Karşılaştırılması(2018) Malgaca, Levent; Uyar, MehmetGünümüzde piezoelektrik malzemeler algılayıcı veya uyarıcı olarak mühendislik uygulamalarında sıklıkla kullanılmaktadır. En yaygın kullanılan piezoelektrik malzeme kurşun-zirkonyumtitanyum (PZT) piezo seramiktir. Piezo seramikler karakteristik özelliklerine göre yumuşak ve sert olarak iki ana sınıfa ayrılırlar ve PZT-2, PZT-4, PZT-5A, PZT-5H, PZT-8 olarak isimlendirilirler. Bu çalışmada, akıllı bir kirişte farklı karakteristikti piezoelektrik algılayıcının dinamik cevapları sonlu elemanlar yöntemi kullanılarak ANSYS/Workbench programında incelenmiştir. Akıllı kiriş, alüminyum kiriş ile bir piezoelektrik algılayıcı ve bir piezoelektrik uyarıcıdan oluşmuştur. Akıllı kirişte hem uç noktasına tekil kuvvet, hem uyarıcıya voltaj, darbe ve adım girdiler şeklinde uygulanmıştır. Algılayıcı ve yer değiştirme sinyalleri dinamik analiz yapılarak elde edilmiştir. Akıllı kirişin piezoelektrik algılayıcı konumu ve karakteristiğine göre farklı dinamik cevaplar verdiği gözlemlenmiştir.Öğe Implementation of Active and Passive Vibration Control of Flexible Smart Composite Manipulators with Genetic Algorithm(Institute for Ionics, 2023) Uyar, Mehmet; Malgaca, L.Endpoint vibrations of flexible manipulators (FM) are suppressed using active or passive control techniques. Suppressing vibrations increases the dynamic performance of the FM in engineering applications. In this study, a model extraction approach is proposed for vibration suppression of single-link flexible smart and composite manipulators. Active and passive control (APC) of residual vibrations is studied theoretically and experimentally. The smart manipulator consists of patching a piezoelectric (PZT) actuator to an aluminum and composite link. The finite element (FE) model of smart manipulators, including revolute joint and PZT actuator, is created in ANSYS. The motion profile and actuator voltage are the inputs, the tip displacement is the output. Then, the state-space (SS) mathematical models of the smart manipulators are extracted from the FE models by using the inputs and outputs. The open-loop and closed-loop simulations are performed using the extracted mathematical models in MATLAB. Passive control is achieved by the motion profiles, while active control is achieved by the PZT actuators. The PD controller with the displacement feedback is used to create the actuation voltages. For the optimized APC, the PD gains are optimized with a genetic algorithm by using the integral of the squared error and integral of absolute magnitude of the error fitness functions. Residual vibrations of smart manipulators are successfully reduced by the optimized APC. To verify the simulation results, open-loop and closed-loop experiments are carried out. The SS mathematical model successfully predicts the dynamic performance of FSM for various motion profiles, according to experimental results. © 2022, King Fahd University of Petroleum & Minerals.Öğe Investigation of vibration performance of pure active single and multi-feedback controls for a tall RC building(Elsevier Science Inc, 2023) Uyar, Mehmet; Ergun, MustafaStructural control methods are applied to eliminate the structural damages caused by the vibrations in the buildings and to improve their dynamic behavior of them under dynamic lateral loads. In this paper, the pure active control performance of a tall building under the influence of earthquake records, in which the effective time duration is determined by considering the ARIAS energy distribution, is presented. The building's pure active control performance in the period when the earthquake records have the maximum effect on the structure is examined. Eleven earthquake records are selected to better evaluate the effect of vibration control perfor-mance. A genetic algorithm is used to determine the parameters of single and multi-feedback controllers, and its effect on the vibration eliminations at the top and all floors is studied. Also, the effect of displacement and velocity feedback on seismic vibration control is evaluated. To carry out the vibration control studies of the building, the mathematical model is extracted from the finite element model created in ANSYS and verified with finite element analysis. It is observed that the displacement value at a reference location on the building is reduced from 0.735 m to 0.019 m, 0.004 m, and 0.002 m, respectively, by the Proportional-Integral-Derivative, Direct Velocity Feedback, and Optimal controllers. The results show that the multi-feedback control is more effective than the single-feedback control application in reducing the vibration amplitudes at all floors in the pure active control system.Öğe Joule heating of carbon fiber in hybrid composites with glass fibers: Investigation of electro-thermal and vibration characteristics(Elsevier, 2025) Uslu, Emin; Yilmaz, Galip; Uyar, MehmetThis study explores the innovative dual-purpose use of carbon fiber, functioning both as a structural and a heating element, expanding its potential in hybrid composites. A prototype composite was fabricated using the vacuum infusion process, featuring a single carbon fiber layer at the core for dual-purpose and two outer layers of glass fiber. Electrical heating tests revealed a stable relationship between voltage, resistance, power, and temperature, demonstrating efficient heat generation as the voltage increased. Thermal imaging confirmed uniform heat distribution with minor variations. Free vibration tests evaluated the composite's dynamic behavior under various electro-thermal conditions. Results showed that increasing temperature reduced the natural frequencies, particularly in the second vibration mode. Changes in Rayleigh damping coefficients at higher temperatures highlighted the composite's sensitivity to thermal inputs. These findings underline the potential of hybrid composites for advanced applications like turbine blades and aerospace components, where multifunctionality, self-heating, and vibration control are critical.Öğe Performance analysis of piezoelectric-based energy harvesting in reinforced concrete buildings under seismic and live loads(Springer Heidelberg, 2025) Ergun, Mustafa; Uyar, Mehmet; Malgaca, LeventThe demand for autonomous energy solutions in seismic regions is increasing for the uninterrupted operation of structural health monitoring systems. In this context, energy harvesting systems offer a solution for low-power devices, especially in earthquake zones where external energy sources may be interrupted. This study evaluates the energy harvesting capacity of a piezoelectric energy harvesting mechanism placed at specific locations in the columns of a reinforced concrete structure, considering both earthquake and live load conditions. A smart building model is developed by placing sensor modules with piezoelectric material on the columns of a three-story reinforced concrete building. The finite element model of the smart building, which is formed by integrating various technologies and sensors, is created in ANSYS, and specific locations on the columns are selected as sensor points. Dynamic analyses are performed under earthquake conditions by considering seismic records from the Imperial Valley, Erzincan, and Darfield earthquakes. Experimental results of a smart structure with patched piezoelectric material are used to verify the simulation results. The voltage, current, and power responses obtained from the sensor points are examined with the payload effect placed at the end point of the sensor module. When the power values collected from the sensor points are compared, it can be said that the maximum power obtained from the smart building under both earthquake and live load is 0.355 W, while the minimum power value reaches 0.168 W. The results show that the energy harvesting mechanism can provide external power to support electronic devices in regions where earthquake effects are frequent and high. Thus, this study presents an innovative contribution to smart building systems by investigating the energy harvesting potential under earthquake and live loads in a reinforced concrete structure equipped with piezoelectric sensors. The model, validated with numerical and experimental analyses, proposes a sustainable energy source for structural health monitoring systems in seismic regions.Öğe Seismic behavior assessment of RC buildings controlled by passive and active techniques(2024) Ergün, Mustafa; Uyar, MehmetIn this paper, a numerical study was carried out on the effectiveness of the active earthquake control method in improving the earthquake response of RC buildings. High damping rubber bearing design was made according to the criteria of the Uniform Building Code. Three different types of isolators were obtained geometrically. Passive earthquake control of the building was provided by placing these isolators under the columns. For active earthquake control of the building, controller design was realized by integrating it into the FE transient analysis in ANSYS. The active earthquake control design was studied using a force-based and displacement-based controller with acceleration and displacement feedback. The linear dynamic earthquake analysis in the time history of all three states of the building (un-controlled, passive, and active-controlled) was made using the acceleration record of the Seferihisar (İzmir) earthquake. When the results are examined, it is seen that the active earthquake control method provides almost all of the positive behavior expected from the passive earthquake control method. In addition, it eliminates some of the disadvantages of the passive earthquake control method.Öğe Seismic behavior assessment of RC buildings controlled by passive and active techniques(2024) Ergün, Mustafa; Uyar, MehmetIn this paper, a numerical study was carried out on the effectiveness of the active earthquake control method in improving the earthquake response of RC buildings. High damping rubber bearing design was made according to the criteria of the Uniform Building Code. Three different types of isolators were obtained geometrically. Passive earthquake control of the building was provided by placing these isolators under the columns. For active earthquake control of the building, controller design was realized by integrating it into the FE transient analysis in ANSYS. The active earthquake control design was studied using a force-based and displacement-based controller with acceleration and displacement feedback. The linear dynamic earthquake analysis in the time history of all three states of the building (un-controlled, passive, and active-controlled) was made using the acceleration record of the Seferihisar (İzmir) earthquake. When the results are examined, it is seen that the active earthquake control method provides almost all of the positive behavior expected from the passive earthquake control method. In addition, it eliminates some of the disadvantages of the passive earthquake control method.Öğe SimMechanics ile Esnek Bir Yapının Modellenmesi ve Titreşim Sönümlemesi(Osman SAĞDIÇ, 2021) Uyar, MehmetBu çalışmada, SimMechanics'te esnek bir kirişin modellenmesi ve simülasyonu incelenmiş ve ardından ANSYS'te sonlu elemanlar (FE) modeli ile titreşim sonuçları doğrulanmıştır. MATLAB'de SimMechanics tabanlı esnek kiriş modeli oluşturulurken, FE modeli ANSYS'de kurulmuştur. Sistemin girdileri, bir kuvvet tabanlı uyarıcı ve bozucu kuvvet olarak belirlenir. Sistemin çıkışları, esnek kirişin uç noktasındaki yer değiştirme ve ivme sinyalleri olarak seçilir. Sönümsüz doğal frekanslar, ANSYS'de modal analiz ve MATLAB'da frekans analizi ile belirlenir. Titreşim cevaplarını elde etmek için geçici analizler yapılır. Açık döngü cevapları için, yer değiştirme ve ivme titreşim sonuçları, adım ve harmonik uyarılar kullanılarak doğrulanır. Uç nokta konumunu kontrol etmek için FE ve SimMechanics modellerine PID kontrolörlü kapalı döngü kontrol uygulanır. Açık ve kapalı döngü titreşim sonuçları, farklı kontrolör kazançları için belirlenmiştir. Açık ve kapalı döngü sonuçlarının, FE modeli ve SimMechanics ile başarılı bir şekilde eşleştirildiği gözlemlenmiştir. SimMechanics tabanlı esnek kiriş modelinin doğruluğu FE modeli ile doğrulanmıştır.Öğe Study on dynamic modelling and vibration analysis of single-link flexible manipulator(2023) Uyar, MehmetIn this study, SimMechanics-based dynamic modeling and vibration analysis of a single-link flexible manipulator are studied. A flexible beam model is set up for modeling the manipulator. Transient analysis is performed to obtain the endpoint acceleration vibration responses of the manipulator moved with different motion profiles. Both the experimental and simulation acceleration results are presented for different cases. The root means square (RMS) values of the acceleration responses are calculated to evaluate the compatibility performance in verifying the simulation results with the experimental results. It has been observed that the results match each other successfully for different cases. The reliability of the SimMechanics-based dynamic modeling method of manipulators is discussed with the experimental results.Öğe Study on dynamic modelling and vibration analysis of single-link flexible manipulator(Gumushane University, 2023) Uyar, MehmetIn this study, SimMechanics-based dynamic modeling and vibration analysis of a single-link flexible manipulator are studied. A flexible beam model is set up for modeling the manipulator. Transient analysis is performed to obtain the endpoint acceleration vibration responses of the manipulator moved with different motion profiles. Both the experimental and simulation acceleration results are presented for different cases. The root means square (RMS) values of the acceleration responses are calculated to evaluate the compatibility performance in verifying the simulation results with the experimental results. It has been observed that the results match each other successfully for different cases. The reliability of the SimMechanics-based dynamic modeling method of manipulators is discussed with the experimental results. © 2023, Gumushane University. All rights reserved.
