Piezoelectric shunt damping has been widely used in vibration suppression, sound absorption, noise elimination, etc. In such applications, the variant elastic constants of piezoelectric materials are the essential par...Piezoelectric shunt damping has been widely used in vibration suppression, sound absorption, noise elimination, etc. In such applications, the variant elastic constants of piezoelectric materials are the essential parameters that determine the performances of the systems, when piezoelectric materials are shunted to normal electrical elements, i.e., resistance, inductance and capacitance, as well as their combinations. In recent years, many researches have demonstrated that the wideband sound absorption or vibration suppression can be realized with piezoelectric materials shunted to negative capacitance. However, most systems using the negative-capacitance shunt circuits show their instabilities in the optimal condition, which are essentially caused by the singular variation properties of elastic constants of piezoelectric materials when shunted to negative capacitance. This paper aims at investigating the effects of negative-capacitance shunt circuits on elastic constants of a piezoelectric ceramic plate through theoretical analyses and experiments, which gives an rational explanation for why negative capacitance shunt circuit is prone to make structure instable. First, the relationships between the elastic constants c11, c33, c55 of the piezoelectric ceramic and the shunt negative capacitance are derived with the piezoelectric constitutive law theoretically. Then, an experimental setup is established to verify the theoretical results through observing the change of elastic constant c55 of the shunted piezoelectric plate with the variation of negative capacitance. The experimental results are in good agreement with the theoretical analyses, which reveals that the instability of the shunt damping system is essentially caused by the singular variation property of the elastic constants of piezoelectric material shunted to negative capacitance.展开更多
The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)tr...The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)transducers for the production of facial masks in the welding process are in heavy demand.In the earlier days of the epidemic,the supply of ceramic transducers cannot meet its increasing demands,and efforts in materials,development,and production are mobilized to provide the transducers to mask producers for quick production.The simplest solution is presented with the employment of Rayleigh-Ritz method for the vibration analysis,then different materials can be selected to achieve the required frequency and energy standards.The fully tailored method and results can be utilized by the engineers for quick development of the PZT transducers to perform precise function in welding.展开更多
CuO added Pb0.92Sr0.06Ba0.02（Mg1/3Nb2/3）0.25（Ti0.53Zr0.47）0.75O3 ceramics were studied to prepare high-quality multilayer piezoelectric actuators with pure Ag electrodes at 900 ℃. CuO addition not only reduced th...CuO added Pb0.92Sr0.06Ba0.02（Mg1/3Nb2/3）0.25（Ti0.53Zr0.47）0.75O3 ceramics were studied to prepare high-quality multilayer piezoelectric actuators with pure Ag electrodes at 900 ℃. CuO addition not only reduced the sintering temperature significantly from 1260 ℃ to 900 ℃ but also improved the ceramic density to 7.742 g/cm3. The 0.7 wt.% CuO added ceramic sintered at 900 ℃ shows the remnant polarization （Pr） of 40 μC/cm2, 0.28% strain at 40 kV/cm, and the piezoelectric coefficient （d33） of 630 pC/N. This ceramic shows a strong relaxor characteristic with a Curie temperature of 200 ℃. Furthermore, the 0.7 wt.% CuO added ceramic and pure Ag electrodes were co-fired at 900 ℃ to prepare a high-quality multilayer piezoelectric actuator with a d33 of over 450 pC/N per ceramic layer.展开更多
Metal-core piezoelectric fibers （MPFs） are one of the new type piezoelectric devices. To investigate the piezoelectricity and the mechanical properties of the piezoelectric fibers, the constitutive equations are est...Metal-core piezoelectric fibers （MPFs） are one of the new type piezoelectric devices. To investigate the piezoelectricity and the mechanical properties of the piezoelectric fibers, the constitutive equations are established. It can describe the response of piezoelectric fibers subject to an axial force and an external voltage. A cantilever bar subject to a tip axial force and an external voltage on the electrodes is considered. The internal energy density in thermodynamic equilibrium is obtained. The total internal energy is calculated by integrating over the entire volume of the bar. The generalized displacement of the tip axial force is the tip elongation δ, and the generalized displacement of the voltage is the electrical charge Q on the electrodes. In the established constitutive equations, the excitation （input） parameters are the axial force and the external voltage, the response （output） parameters are the tip elongation and the electric charge. And the response parameters are related to the excitation parameters by a 2× 2 piezoelectric matrix. Finally, two experiments using MPF as a sensor or an actuator are performed to verify the constitutive equations. And experimental results are compared with analytical ones.展开更多
Piezoelectric atomizers exhibit the advantages of structural simplicity,portability,low energy consumption,low production costs,and good atomization.They have been extensively used in various fields,including inhalati...Piezoelectric atomizers exhibit the advantages of structural simplicity,portability,low energy consumption,low production costs,and good atomization.They have been extensively used in various fields,including inhalation therapy,inkjet printing,and spray cooling.Here,the research of piezoelectric atomizers is first summarized from the perspectives of theoretical investigation and applications.Subsequently,the existing investigation and applications on piezoelectric atomizers are classified in terms of their functionalities.The functions of inkjet printing,spray cooling,and inhalation therapy are described in detail.Finally,the future trends in this field are analyzed.It is indicated that the vibrating-mesh atomizer has a promising prospect in the market,signaling strong demand especially in upgaraded consumption and medical scenarios.展开更多
Piezoelectric ceramic element (PCE) is a kind of actuator applied widely on the intelligent material & structure. Establishing the relationship between the transferring stress and the controlling signal, namely t...Piezoelectric ceramic element (PCE) is a kind of actuator applied widely on the intelligent material & structure. Establishing the relationship between the transferring stress and the controlling signal, namely the transferring and actuating equation, is a key step to analyze the actuating performance of the PCE. Based on the method of the shear lag theory, the procedure of the stress transferring is analyzed and the transferring and actuating model is established in this paper. Some measurements for PCE(PZT5) actuating the Glass Fiber/Epoxy laminate have been done to verify the model established. The experimental results show that the theoretical model agrees well with the practice. Finally, the effect of the main factors on PCE actuating the laminate is studied by using the experimental and theoretical results.展开更多
The principles and methods of active vibration control on a flexible cantilever beam using piezoelectric patches as actuators is studied. Active control of the first two modes of the flexible can- tilever beam is impl...The principles and methods of active vibration control on a flexible cantilever beam using piezoelectric patches as actuators is studied. Active control of the first two modes of the flexible can- tilever beam is implemented based on the independent modal control law. Experimental results show that the structural damping of the flexible cantilever beam is effectively improved and an excellent degree of vibration suppression is achieved with the active vibration control strategy.展开更多
In this paper, the preparation of 0.08BiGaO3–0.90BaTiO3–0.02LiNbO3 is investigated at pressure 3.8 GPa and temperature 1100–1200？C. Experimental results indicate that not only is the sintered rate more effective, ...In this paper, the preparation of 0.08BiGaO3–0.90BaTiO3–0.02LiNbO3 is investigated at pressure 3.8 GPa and temperature 1100–1200？C. Experimental results indicate that not only is the sintered rate more effective, but also the sintered temperature is lower under high pressure and high temperature than those of under normal pressure. It is thought that the adscititious pressure plays the key role in this process, which is discussed in detail. The composition and the structure of the as-prepared samples are recorded by XRD patterns. The result shows that the phases of Ba TiO3, BaBiO（2.77）, and Ba2Bi4Ti5O（18） with piezoelectric ceramic performance generate in the sintered samples. Furthermore, the surface morphology characteristics of the typical samples are also investigated using a scanning electron microscope. It indicates that the grain size and surface structure of the samples are closely related to the sintering temperature and sintering time. It is hoped that this study can provide a new train of thought for the preparation of lead-free piezoelectric ceramics with excellent performance.展开更多
The FitzHugh–Nagumo neuron circuit integrates a piezoelectric ceramic to form a piezoelectric sensing neuron,which can capture external sound signals and simulate the auditory neuron system.Two piezoelectric sensing ...The FitzHugh–Nagumo neuron circuit integrates a piezoelectric ceramic to form a piezoelectric sensing neuron,which can capture external sound signals and simulate the auditory neuron system.Two piezoelectric sensing neurons are coupled by a parallel circuit consisting of a Josephson junction and a linear resistor,and a binaural auditory system is established.Considering the non-singleness of external sound sources,the high–low frequency signal is used as the input signal to study the firing mode transition and synchronization of this system.It is found that the angular frequency of the high–low frequency signal is a key factor in determining whether the dynamic behaviors of two coupled neurons are synchronous.When they are in synchronization at a specific angular frequency,the changes in physical parameters of the input signal and the coupling strength between them will not destroy their synchronization.In addition,the firing mode of two coupled auditory neurons in synchronization is affected by the characteristic parameters of the high–low frequency signal rather than the coupling strength.The asynchronous dynamic behavior and variations in firing modes will harm the auditory system.These findings could help determine the causes of hearing loss and devise functional assistive devices for patients.展开更多
Block piezoelectric ceramics(PZTs)are often used in impact igniters to provide activation energy for electric initiators.Under the action of strong impact stress,PZTs release electric energy accompanied by crack initi...Block piezoelectric ceramics(PZTs)are often used in impact igniters to provide activation energy for electric initiators.Under the action of strong impact stress,PZTs release electric energy accompanied by crack initiation,propagation and crushing.At present,the electrical output performance of PZTs in projectile is usually calculated by quasi-static piezoelectric equation without considering the dynamic effect caused by strong impact and the influence of crack propagation on material properties.So the ignition parameters are always not accurately predicted.To tackle this,a PZT dynamic damage constitutive model considering crack propagation is established based on the dynamic impact test and the crack propagation theory of brittle materials.The model is then embedded into the ABAQUS subroutine and used to simulate the electromechanical response of the impact igniter during the impact of a small caliber projectile on the target.Meanwhile,the experiments of projectile with impact igniter impact on the target are carried out.The comparison between experimental and numerical simulation results show that the established dynamic damage model can effectively predict the dynamic electromechanical response of PZTs in the missile service environment.展开更多
To study the non-linear fracture, a non-linear constitutive model for piezoelectric ceramics was proposed, in which the polarization switching and saturation were taken into account. Based on the model, the non-linear...To study the non-linear fracture, a non-linear constitutive model for piezoelectric ceramics was proposed, in which the polarization switching and saturation were taken into account. Based on the model, the non-linear fracture analysis was implemented using reproducing kernel particle method （RKPM）. Using local J-integral as a fracture criterion, a relation curve of fracture loads against electric fields was obtained. Qualitatively, the curve is in agreement with the experimental observations reported in literature. The reproducing equation, the shape function of RKPM, and the transformation method to impose essential boundary conditions for meshless methods were also introduced. The computation was implemented using object-oriented programming method.展开更多
文摘Piezoelectric shunt damping has been widely used in vibration suppression, sound absorption, noise elimination, etc. In such applications, the variant elastic constants of piezoelectric materials are the essential parameters that determine the performances of the systems, when piezoelectric materials are shunted to normal electrical elements, i.e., resistance, inductance and capacitance, as well as their combinations. In recent years, many researches have demonstrated that the wideband sound absorption or vibration suppression can be realized with piezoelectric materials shunted to negative capacitance. However, most systems using the negative-capacitance shunt circuits show their instabilities in the optimal condition, which are essentially caused by the singular variation properties of elastic constants of piezoelectric materials when shunted to negative capacitance. This paper aims at investigating the effects of negative-capacitance shunt circuits on elastic constants of a piezoelectric ceramic plate through theoretical analyses and experiments, which gives an rational explanation for why negative capacitance shunt circuit is prone to make structure instable. First, the relationships between the elastic constants c11, c33, c55 of the piezoelectric ceramic and the shunt negative capacitance are derived with the piezoelectric constitutive law theoretically. Then, an experimental setup is established to verify the theoretical results through observing the change of elastic constant c55 of the shunted piezoelectric plate with the variation of negative capacitance. The experimental results are in good agreement with the theoretical analyses, which reveals that the instability of the shunt damping system is essentially caused by the singular variation property of the elastic constants of piezoelectric material shunted to negative capacitance.
基金supported in part by the National Natural Science Foundation of China(No.11672142)the Technology Innovation 2025 Program of the Municipality of Ningbo(No.2019B10122)。
文摘The explosive demands for facial masks as vital personal protection equipment(PPE)in the wake of Covid-19 have challenged many industries and enterprises in technology and capacity,and the piezoelectric ceramic(PZT)transducers for the production of facial masks in the welding process are in heavy demand.In the earlier days of the epidemic,the supply of ceramic transducers cannot meet its increasing demands,and efforts in materials,development,and production are mobilized to provide the transducers to mask producers for quick production.The simplest solution is presented with the employment of Rayleigh-Ritz method for the vibration analysis,then different materials can be selected to achieve the required frequency and energy standards.The fully tailored method and results can be utilized by the engineers for quick development of the PZT transducers to perform precise function in welding.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51472118,51602156,52177072,and 11274174)the Fundamental Research Funds for the Central Universities,China(Grant Nos.30916011104 and 30916011208)
文摘CuO added Pb0.92Sr0.06Ba0.02（Mg1/3Nb2/3）0.25（Ti0.53Zr0.47）0.75O3 ceramics were studied to prepare high-quality multilayer piezoelectric actuators with pure Ag electrodes at 900 ℃. CuO addition not only reduced the sintering temperature significantly from 1260 ℃ to 900 ℃ but also improved the ceramic density to 7.742 g/cm3. The 0.7 wt.% CuO added ceramic sintered at 900 ℃ shows the remnant polarization （Pr） of 40 μC/cm2, 0.28% strain at 40 kV/cm, and the piezoelectric coefficient （d33） of 630 pC/N. This ceramic shows a strong relaxor characteristic with a Curie temperature of 200 ℃. Furthermore, the 0.7 wt.% CuO added ceramic and pure Ag electrodes were co-fired at 900 ℃ to prepare a high-quality multilayer piezoelectric actuator with a d33 of over 450 pC/N per ceramic layer.
基金the National High Technology Research and Development Program of China(863Pro-gram)(2007AA03Z104)~~
文摘Metal-core piezoelectric fibers （MPFs） are one of the new type piezoelectric devices. To investigate the piezoelectricity and the mechanical properties of the piezoelectric fibers, the constitutive equations are established. It can describe the response of piezoelectric fibers subject to an axial force and an external voltage. A cantilever bar subject to a tip axial force and an external voltage on the electrodes is considered. The internal energy density in thermodynamic equilibrium is obtained. The total internal energy is calculated by integrating over the entire volume of the bar. The generalized displacement of the tip axial force is the tip elongation δ, and the generalized displacement of the voltage is the electrical charge Q on the electrodes. In the established constitutive equations, the excitation （input） parameters are the axial force and the external voltage, the response （output） parameters are the tip elongation and the electric charge. And the response parameters are related to the excitation parameters by a 2× 2 piezoelectric matrix. Finally, two experiments using MPF as a sensor or an actuator are performed to verify the constitutive equations. And experimental results are compared with analytical ones.
基金This work was supported by the National Natural Science Foundation of China(No.51375227)。
文摘Piezoelectric atomizers exhibit the advantages of structural simplicity,portability,low energy consumption,low production costs,and good atomization.They have been extensively used in various fields,including inhalation therapy,inkjet printing,and spray cooling.Here,the research of piezoelectric atomizers is first summarized from the perspectives of theoretical investigation and applications.Subsequently,the existing investigation and applications on piezoelectric atomizers are classified in terms of their functionalities.The functions of inkjet printing,spray cooling,and inhalation therapy are described in detail.Finally,the future trends in this field are analyzed.It is indicated that the vibrating-mesh atomizer has a promising prospect in the market,signaling strong demand especially in upgaraded consumption and medical scenarios.
文摘Piezoelectric ceramic element (PCE) is a kind of actuator applied widely on the intelligent material & structure. Establishing the relationship between the transferring stress and the controlling signal, namely the transferring and actuating equation, is a key step to analyze the actuating performance of the PCE. Based on the method of the shear lag theory, the procedure of the stress transferring is analyzed and the transferring and actuating model is established in this paper. Some measurements for PCE(PZT5) actuating the Glass Fiber/Epoxy laminate have been done to verify the model established. The experimental results show that the theoretical model agrees well with the practice. Finally, the effect of the main factors on PCE actuating the laminate is studied by using the experimental and theoretical results.
基金Supported by the National Natural Science Foundation of China (11172026)
文摘The principles and methods of active vibration control on a flexible cantilever beam using piezoelectric patches as actuators is studied. Active control of the first two modes of the flexible can- tilever beam is implemented based on the independent modal control law. Experimental results show that the structural damping of the flexible cantilever beam is effectively improved and an excellent degree of vibration suppression is achieved with the active vibration control strategy.
基金Project supported by the National Natural Science Foundation of China(Grant No.51172089)the Natural Science Foundation of Education Department of Guizhou Province,China(Grant Nos.KY[2013]183 and LH[2015]7232)the Research Fund for the Doctoral Program of Tongren University,China(Grant No.DS1302)
文摘In this paper, the preparation of 0.08BiGaO3–0.90BaTiO3–0.02LiNbO3 is investigated at pressure 3.8 GPa and temperature 1100–1200？C. Experimental results indicate that not only is the sintered rate more effective, but also the sintered temperature is lower under high pressure and high temperature than those of under normal pressure. It is thought that the adscititious pressure plays the key role in this process, which is discussed in detail. The composition and the structure of the as-prepared samples are recorded by XRD patterns. The result shows that the phases of Ba TiO3, BaBiO（2.77）, and Ba2Bi4Ti5O（18） with piezoelectric ceramic performance generate in the sintered samples. Furthermore, the surface morphology characteristics of the typical samples are also investigated using a scanning electron microscope. It indicates that the grain size and surface structure of the samples are closely related to the sintering temperature and sintering time. It is hoped that this study can provide a new train of thought for the preparation of lead-free piezoelectric ceramics with excellent performance.
基金Project supported by the National Natural Science Foundation of China(Grant No.11605014)。
文摘The FitzHugh–Nagumo neuron circuit integrates a piezoelectric ceramic to form a piezoelectric sensing neuron,which can capture external sound signals and simulate the auditory neuron system.Two piezoelectric sensing neurons are coupled by a parallel circuit consisting of a Josephson junction and a linear resistor,and a binaural auditory system is established.Considering the non-singleness of external sound sources,the high–low frequency signal is used as the input signal to study the firing mode transition and synchronization of this system.It is found that the angular frequency of the high–low frequency signal is a key factor in determining whether the dynamic behaviors of two coupled neurons are synchronous.When they are in synchronization at a specific angular frequency,the changes in physical parameters of the input signal and the coupling strength between them will not destroy their synchronization.In addition,the firing mode of two coupled auditory neurons in synchronization is affected by the characteristic parameters of the high–low frequency signal rather than the coupling strength.The asynchronous dynamic behavior and variations in firing modes will harm the auditory system.These findings could help determine the causes of hearing loss and devise functional assistive devices for patients.
基金supported by the National Natural Science Foundation of China(Grant No.12172232)the project of Key Laboratory of Impact and Safety Engineering(Ningbo University,China)+1 种基金Ministry of Education(CJ202206)supported by the scientific research support plan of introducing high-level talents from Shenyang Ligong University。
文摘Block piezoelectric ceramics(PZTs)are often used in impact igniters to provide activation energy for electric initiators.Under the action of strong impact stress,PZTs release electric energy accompanied by crack initiation,propagation and crushing.At present,the electrical output performance of PZTs in projectile is usually calculated by quasi-static piezoelectric equation without considering the dynamic effect caused by strong impact and the influence of crack propagation on material properties.So the ignition parameters are always not accurately predicted.To tackle this,a PZT dynamic damage constitutive model considering crack propagation is established based on the dynamic impact test and the crack propagation theory of brittle materials.The model is then embedded into the ABAQUS subroutine and used to simulate the electromechanical response of the impact igniter during the impact of a small caliber projectile on the target.Meanwhile,the experiments of projectile with impact igniter impact on the target are carried out.The comparison between experimental and numerical simulation results show that the established dynamic damage model can effectively predict the dynamic electromechanical response of PZTs in the missile service environment.
基金Foundation of Southwest Jiaotong Univer-sity (No.2005B25)
文摘To study the non-linear fracture, a non-linear constitutive model for piezoelectric ceramics was proposed, in which the polarization switching and saturation were taken into account. Based on the model, the non-linear fracture analysis was implemented using reproducing kernel particle method （RKPM）. Using local J-integral as a fracture criterion, a relation curve of fracture loads against electric fields was obtained. Qualitatively, the curve is in agreement with the experimental observations reported in literature. The reproducing equation, the shape function of RKPM, and the transformation method to impose essential boundary conditions for meshless methods were also introduced. The computation was implemented using object-oriented programming method.
