Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2025Scopus SJRQ2Performance analysis of piezoelectric-based energy harvesting in reinforced concrete buildings under seismic and live loads
Ergün, Mustafa; Uyar, Mehmet; Malgaca, Levent
The 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.
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İncele - MakaleAçık Erişim2024Scopus SJRQ2Analysis of an actively controlled composite box manipulator without external actuator
Lök, Şefika İ; Malgaca, Levent; Uyar, Mehmet
This 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.
AtıfScopus3WoS3OpenAlex2İncele - BildiriAçık Erişim2022Experimental Active Vibration Control of a Highly Flexible Composite Manipulator with Acceleration Feedback
Uyar, Mehmet; Malgaca, Levent; Lök, Ş.İpek; Can, Seda Vatan; Herisanu, N.; Marinca, V.
In 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.
AtıfScopus2OpenAlex2İncele - MakaleAçık Erişim2018Farklı Karakteristikli Piezoelektrik Algılayıcıların Dinamik Performanslarının Karşılaştırılması
Uyar, Mehmet; Malgaca, Levent
Günümüzde 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.
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İncele - MakaleAçık Erişim2018Vibration Analysis of a Cantilever Composite Beam by Equivalent MassSpring-Damper Systems
Uyar, Mehmet; Malgaca, Levent; Yavuz, Sahin; Karagülle, Hira
Composite materials are widely used in industrial structures such as manipulators because they are lightweight and durable. In this work, the vibration analysis of a cantilever composite beam with [0/90] lay-up was studied. An end point mass was added to the structure. An initial displacement was applied to the end point and the free vibration was analyzed experimentally first. Exponential decay was found. Natural frequencies were determined by taking the Fast Fourier Transform of the vibration signal. The system was analyzed in ANSYS and simulation results were obtained. The damping coefficient was determined by trial using the experimental exponential decay. An equivalent massspring-damper model (MSD) was established using static deflection, natural frequency and exponential decay obtained experimentally or by simulation. MSD-analytical results were obtained by the Laplace transform method. The experimental, simulation, and analytical results were compared for different end point initial displacement values. It was observed that the results are in good agreement.
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