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R K N D Rajapakse - One of the best experts on this subject based on the ideXlab platform.
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self heat generation in Piezoelectric Stack actuators used in fuel injectors
Smart Materials and Structures, 2009Co-Authors: M S Senousy, R K N D Rajapakse, D Mumford, M S GadalaAbstract:Multilayer Piezoelectric actuators are used in fuel injectors due to their quick response, high efficiency, accuracy, low power consumption, and excellent repeatability. Experimental results for soft lead zirconate titanate (PZT) Stack actuators have shown that a significant amount of heat is generated when they are driven under high frequency and/or high electric-field magnitudes, both of which occur in fuel injectors. Self-heat generation in these actuators, mainly caused by losses, can significantly affect their reliability and Piezoelectric properties, and may also limit their application. Other studies have demonstrated that at large unipolar electric-field magnitudes, displacement–electric-field loss (displacement hysteresis) shows a direct relation with polarization–electric-field loss (dielectric hysteresis). In this paper, a simplified analytical self-heating model is presented. The model directly relates self-heating in multilayer Piezoelectric actuators to displacement–electric-field loss (displacement hysteresis). The model developed is based on the first law of thermodynamics, and accounts for different parameters such as geometry, magnitude and frequency of applied electric field, duty cycle percentage, fuel type, and environmental properties. The model shows reasonable agreement with experimental results at low and high electric-field magnitudes.
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thermo electro mechanical performance of Piezoelectric Stack actuators for fuel injector applications
Journal of Intelligent Material Systems and Structures, 2009Co-Authors: M S Senousy, M S Gadala, D Mumford, R K N D RajapakseAbstract:Piezoelectric actuators are increasingly used in fuel injectors due to their quick response, high efficiency, accuracy, and excellent repeatability. Current understanding of their thermo-electro-mechanical performance under dynamic driving conditions appropriate for fuel injection is, however, limited. In this paper, the thermo-electro-mechanical performance of soft Lead Zirconate Titanate (PZT) Stack actuators is experimentally investigated over a temperature range of -30°C to 80°C, under driving electric fields of up to 2.0 kV/mm (using an AC drive method and a biased DC offset), different frequencies, and a constant preload of about 5 MPa. Experimental results show that the dynamic stroke of the actuators increases with the magnitude and frequency of the applied electric field, as well as ambient temperature. The dynamic stroke was also found to increase with decreased driving field rise time, which is equivalent to increasing the driving field frequency. At driving frequencies lower than the resonance...
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quasi static thermo electro mechanical behaviour of Piezoelectric Stack actuators
Smart Materials and Structures, 2008Co-Authors: R K N D Rajapakse, D Mumford, M S GadalaAbstract:Quasi-static thermo-electro-mechanical performance of annular and solid cylindrical Piezoelectric actuators was studied by experimental means under electric fields varying from 0.3 to 1.8 kV mm −1 with a preload of 4.6 MPa over the temperature range of −30 to 125 ◦ C. It was found that, for both annular and solid actuators, the electrically induced stroke increases steadily with temperature. Under electric fields larger than 1.0 kV mm −1 , a nonlinear transition zone exists in the stroke-temperature plot over the temperature range 25-50 ◦ C. The dielectric constant was also found to increase with temperature. Preload dependence of displacement was measured up to 42 MPa at room temperature and found to be negligible below 30 MPa. A mathematical model that includes the linear Piezoelectric effect and 90 ◦ domain switching effect was used to model the experimental results. The model shows reasonable agreement with experimental results at low and high driving fields. (Some figures in this article are in colour only in the electronic version)
M S Gadala - One of the best experts on this subject based on the ideXlab platform.
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self heat generation in Piezoelectric Stack actuators used in fuel injectors
Smart Materials and Structures, 2009Co-Authors: M S Senousy, R K N D Rajapakse, D Mumford, M S GadalaAbstract:Multilayer Piezoelectric actuators are used in fuel injectors due to their quick response, high efficiency, accuracy, low power consumption, and excellent repeatability. Experimental results for soft lead zirconate titanate (PZT) Stack actuators have shown that a significant amount of heat is generated when they are driven under high frequency and/or high electric-field magnitudes, both of which occur in fuel injectors. Self-heat generation in these actuators, mainly caused by losses, can significantly affect their reliability and Piezoelectric properties, and may also limit their application. Other studies have demonstrated that at large unipolar electric-field magnitudes, displacement–electric-field loss (displacement hysteresis) shows a direct relation with polarization–electric-field loss (dielectric hysteresis). In this paper, a simplified analytical self-heating model is presented. The model directly relates self-heating in multilayer Piezoelectric actuators to displacement–electric-field loss (displacement hysteresis). The model developed is based on the first law of thermodynamics, and accounts for different parameters such as geometry, magnitude and frequency of applied electric field, duty cycle percentage, fuel type, and environmental properties. The model shows reasonable agreement with experimental results at low and high electric-field magnitudes.
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thermo electro mechanical performance of Piezoelectric Stack actuators for fuel injector applications
Journal of Intelligent Material Systems and Structures, 2009Co-Authors: M S Senousy, M S Gadala, D Mumford, R K N D RajapakseAbstract:Piezoelectric actuators are increasingly used in fuel injectors due to their quick response, high efficiency, accuracy, and excellent repeatability. Current understanding of their thermo-electro-mechanical performance under dynamic driving conditions appropriate for fuel injection is, however, limited. In this paper, the thermo-electro-mechanical performance of soft Lead Zirconate Titanate (PZT) Stack actuators is experimentally investigated over a temperature range of -30°C to 80°C, under driving electric fields of up to 2.0 kV/mm (using an AC drive method and a biased DC offset), different frequencies, and a constant preload of about 5 MPa. Experimental results show that the dynamic stroke of the actuators increases with the magnitude and frequency of the applied electric field, as well as ambient temperature. The dynamic stroke was also found to increase with decreased driving field rise time, which is equivalent to increasing the driving field frequency. At driving frequencies lower than the resonance...
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quasi static thermo electro mechanical behaviour of Piezoelectric Stack actuators
Smart Materials and Structures, 2008Co-Authors: R K N D Rajapakse, D Mumford, M S GadalaAbstract:Quasi-static thermo-electro-mechanical performance of annular and solid cylindrical Piezoelectric actuators was studied by experimental means under electric fields varying from 0.3 to 1.8 kV mm −1 with a preload of 4.6 MPa over the temperature range of −30 to 125 ◦ C. It was found that, for both annular and solid actuators, the electrically induced stroke increases steadily with temperature. Under electric fields larger than 1.0 kV mm −1 , a nonlinear transition zone exists in the stroke-temperature plot over the temperature range 25-50 ◦ C. The dielectric constant was also found to increase with temperature. Preload dependence of displacement was measured up to 42 MPa at room temperature and found to be negligible below 30 MPa. A mathematical model that includes the linear Piezoelectric effect and 90 ◦ domain switching effect was used to model the experimental results. The model shows reasonable agreement with experimental results at low and high driving fields. (Some figures in this article are in colour only in the electronic version)
Tobias Melz - One of the best experts on this subject based on the ideXlab platform.
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EACS 2016 paper - OPTIMAL TUNING OF SHUNT PARAMETERS FOR LATERAL BEAM VIBRATION ATTENUATION WITH THREE COLLOCATED Piezoelectric Stack TRANSDUCERS
2017Co-Authors: Enedic Gotz, Roland Platz, Olive Heuss, Tobias MelzAbstract:EACS 2016 Paper No. 149Structural vibration may occur in mechanical systems leading to fatigue, reduced durability or undesirable noise. In this context, shunting Piezoelectric transducers to RL-shunts can be an appropriate measure for attenuating lateral beam vibrations. The achieved vibration attenuation significantly depends on an adequate tuning of the shunt to the structural resonance mode. In this paper, an existing method for resonant shunt circuit tuning based on electrical impedances is extended for lateral vibration attenuation of the first mechanical mode of a beam with circular cross-section and three collocated resonantly shunted Stack transducers. It is shown by numerical simulation that a presented electrical impedance model including only the first beam mode can be used for the shunt parameter optimization if higher beam modes are taken into account
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lateral vibration attenuation of a beam with circular cross section by a support with integrated Piezoelectric transducers shunted to negative capacitances
Smart Materials and Structures, 2016Co-Authors: Benedict Gotz, Maximilian Schaeffner, Roland Platz, Tobias MelzAbstract:Undesired vibration may occur in lightweight structures due to excitation and low damping. For the purpose of lateral vibration attenuation in beam structures, Piezoelectric transducers shunted to negative capacitances can be an appropriate measure. In this paper, a new concept for lateral vibration attenuation by integrated Piezoelectric Stack transducers in the elastic support of a beam with circular cross-section is presented. In the piezoelastic support, bending of the beam in an arbitrary direction is transformed into a significant axial deformation of three Stack transducers and, thus, the beam's surface may remain free from transducers. For multimodal vibration attenuation, each Piezoelectric transducer is shunted to a negative capacitance. It is shown by numerical simulation and experiment that the concept of an elastic beam support with integrated shunted Piezoelectric Stack transducers is capable of reducing the lateral vibration of the beam in an arbitrary direction.
D Mumford - One of the best experts on this subject based on the ideXlab platform.
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self heat generation in Piezoelectric Stack actuators used in fuel injectors
Smart Materials and Structures, 2009Co-Authors: M S Senousy, R K N D Rajapakse, D Mumford, M S GadalaAbstract:Multilayer Piezoelectric actuators are used in fuel injectors due to their quick response, high efficiency, accuracy, low power consumption, and excellent repeatability. Experimental results for soft lead zirconate titanate (PZT) Stack actuators have shown that a significant amount of heat is generated when they are driven under high frequency and/or high electric-field magnitudes, both of which occur in fuel injectors. Self-heat generation in these actuators, mainly caused by losses, can significantly affect their reliability and Piezoelectric properties, and may also limit their application. Other studies have demonstrated that at large unipolar electric-field magnitudes, displacement–electric-field loss (displacement hysteresis) shows a direct relation with polarization–electric-field loss (dielectric hysteresis). In this paper, a simplified analytical self-heating model is presented. The model directly relates self-heating in multilayer Piezoelectric actuators to displacement–electric-field loss (displacement hysteresis). The model developed is based on the first law of thermodynamics, and accounts for different parameters such as geometry, magnitude and frequency of applied electric field, duty cycle percentage, fuel type, and environmental properties. The model shows reasonable agreement with experimental results at low and high electric-field magnitudes.
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thermo electro mechanical performance of Piezoelectric Stack actuators for fuel injector applications
Journal of Intelligent Material Systems and Structures, 2009Co-Authors: M S Senousy, M S Gadala, D Mumford, R K N D RajapakseAbstract:Piezoelectric actuators are increasingly used in fuel injectors due to their quick response, high efficiency, accuracy, and excellent repeatability. Current understanding of their thermo-electro-mechanical performance under dynamic driving conditions appropriate for fuel injection is, however, limited. In this paper, the thermo-electro-mechanical performance of soft Lead Zirconate Titanate (PZT) Stack actuators is experimentally investigated over a temperature range of -30°C to 80°C, under driving electric fields of up to 2.0 kV/mm (using an AC drive method and a biased DC offset), different frequencies, and a constant preload of about 5 MPa. Experimental results show that the dynamic stroke of the actuators increases with the magnitude and frequency of the applied electric field, as well as ambient temperature. The dynamic stroke was also found to increase with decreased driving field rise time, which is equivalent to increasing the driving field frequency. At driving frequencies lower than the resonance...
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quasi static thermo electro mechanical behaviour of Piezoelectric Stack actuators
Smart Materials and Structures, 2008Co-Authors: R K N D Rajapakse, D Mumford, M S GadalaAbstract:Quasi-static thermo-electro-mechanical performance of annular and solid cylindrical Piezoelectric actuators was studied by experimental means under electric fields varying from 0.3 to 1.8 kV mm −1 with a preload of 4.6 MPa over the temperature range of −30 to 125 ◦ C. It was found that, for both annular and solid actuators, the electrically induced stroke increases steadily with temperature. Under electric fields larger than 1.0 kV mm −1 , a nonlinear transition zone exists in the stroke-temperature plot over the temperature range 25-50 ◦ C. The dielectric constant was also found to increase with temperature. Preload dependence of displacement was measured up to 42 MPa at room temperature and found to be negligible below 30 MPa. A mathematical model that includes the linear Piezoelectric effect and 90 ◦ domain switching effect was used to model the experimental results. The model shows reasonable agreement with experimental results at low and high driving fields. (Some figures in this article are in colour only in the electronic version)
Xiaoting Rui - One of the best experts on this subject based on the ideXlab platform.
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modeling and control of a two axis fast steering mirror with Piezoelectric Stack actuators for laser beam tracking
Smart Materials and Structures, 2015Co-Authors: Wei Zhu, Gangli Che, Yi A, Xiaoting RuiAbstract:This paper outlines an optical beam steering system built using a two-axis fast steering mirror (FSM) with Piezoelectric Stack actuators to maintain precise pointing control. A novel mathematical model of the FSM is put forward by using a transfer matrix method of a multibody system to describe the dynamics characteristics and a hysteresis model to represent the hysteresis. Based on the proposed model, a model-based hybrid control is applied to force the output angle of the FSM to track the laser beam accurately thereafter. The experimental results are in accordance with the theoretical analysis. The results highlight significantly improved accuracy in the beam tracking control of the FSM.
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transfer matrix method for multibody systems for Piezoelectric Stack actuators
Smart Materials and Structures, 2014Co-Authors: Wei Zhu, Gangli Che, Xiaoting RuiAbstract:In order to achieve a large displacement output from a Piezoelectric actuator, we realized the Piezoelectric Stack actuator (PSA) by mechanically layering/Stacking multi-chip Piezoelectric wafers in a series and electrically connecting the electrodes in parallel. In this paper, in order to accurately model the hysteresis and the dynamic characteristics of a PSA, the transfer matrix method for multibody systems (MSTMM) was adopted to describe the dynamic characteristics, and the Bouc-Wen hysteresis operator was used to represent the hysteresis. The vibration characteristics of a PSA and a piezo-actuated positioning mechanism (PPM) are derived and analyzed by the MSTMM; then, the dynamic responses of the PSA and the PPM are calculated. The experimental results show that the new method can accurately portray the hysteresis and the dynamic characteristics of a PSA and a PPM. On one hand, if we use this method to model the dynamic response of the PSA and the PPM, the PSA can be considered as a flexible body, as opposed to a mass-spring-damper system, which is in better agreement with the actual condition. On the other hand, the global dynamics equation is not needed for the study of system dynamics, and the dynamics equation has a small-sized matrix and a higher computational speed. Therefore, this method gives a broad range of possibilities for model-based controller design.