Aiming at a kind of middle ear implant（MEI）, the driving voltage of a piezoelectric floating mass actuator is analyzed using a 0. 7Pb （Mg1/3Nb2/3） O3-0. 3PbTiO3 （ PMN- 30% PT）stack as a new type of vibrator. For...Aiming at a kind of middle ear implant（MEI）, the driving voltage of a piezoelectric floating mass actuator is analyzed using a 0. 7Pb （Mg1/3Nb2/3） O3-0. 3PbTiO3 （ PMN- 30% PT）stack as a new type of vibrator. For the purpose of facilitating the analysis, a simplified coupling model of the ossicular chain and the piezoelectric actuator is constructed. First, a finite element model of a human middle ear is constructed by reverse engineering technology, and the validity of this model is confirmed by comparing the simulated motion of the stapes footplate obtained by this model with experimental measurements. Then the displacement impedance of the incus long process is analyzed, and a single mass-spring-damper equivalent model of the ossicular chain attached with the clamp is derived. Finally, a simplified coupling model of the ossicular chain and the piezoelectric actuator is established and used to analyze the driving voltage property of the actuator. The results show that the required driving voltage decreases with the increase in the frequency, and the maximum required driving voltage is 20. 9 V in the voice frequencies. However, in the mid-high frequencies where most sensorineural hearing loss occurs, the maximum required driving voltage is 3.8 V, which meets the low-voltage and low-power requirements of the MEI.展开更多
To overcome some of the problems inherent in conventional heating aids such as low gain at high fi'equencies due to acoustic feedback,discomfort in occlusion of the extemal ear canal and so on,implantable middle e...To overcome some of the problems inherent in conventional heating aids such as low gain at high fi'equencies due to acoustic feedback,discomfort in occlusion of the extemal ear canal and so on,implantable middle ear hearing devices(IMEHDs)have been developed over the past two decades.For such kinds of IMEHDs,this paper presents the design of a floating mass piezoelectric actuator using a PMN-30%PT stack as a new type of vibrator.The proposed piezoelectric actuator consists of only three components of a piezoelectric stack,a metal case and a clamp.For the purpose of aiding the design of this actuator,a coupling biomechanics model of human middle ear and the piezoelectric actuator was constructed.This model was built based on a complete set of computerized tomography section images of a healthy volunteer's left ear by reverse engineering technology.The validity of this model was confirmed by comparing the motion of the tympanic membrane and stapes footplate obtained by this model with published experimental measurements on human temporal bones.It is shown that the designed actuator can be implanted on the incus long process by a simple surgical operation,and the stapes footplate displacement by its excitation at 10.5 V root-mean-square(RMS)voltage was equivalent to that from acoustic stimulation at 100 dB sound pressure level(SPL),which is adequate stimulation to the ossicular chain.The corresponding power consumption is 0.04 mW per volt of excitation at 1 kHz,which is low enough for the transducer to be used in an implantable middle ear device.展开更多
考虑到海上浮式风机(floating offshore wind turbine,FOWT)因存在整体晃动导致背景响应强烈,在频域上有时表现为激励频率,且随激励频率的变化而变化,在使用传统调谐质量阻尼器(tuned mass damper,TMD)对其进行振动控制时出现频率失调...考虑到海上浮式风机(floating offshore wind turbine,FOWT)因存在整体晃动导致背景响应强烈,在频域上有时表现为激励频率,且随激励频率的变化而变化,在使用传统调谐质量阻尼器(tuned mass damper,TMD)对其进行振动控制时出现频率失调和效果不佳等现象,该研究设计并提出了一种带碰撞的磁流变弹性体变刚度调谐质量阻尼器(magnetorheological elastomer-pounding tuned mass damper,MRE-PTMD)对FOWT实施半主动控制。在该控制装置中,利用MRE的刚度可调特性,通过半主动控制技术实现阻尼器频率的实时调节,保持对FOWT的最优控制,同时引入限位挡板对MRE材料加以保护并实现碰撞耗能。以驳船型FOWT为例,建立了包含控制装置的17自由度动力方程,对其在风浪联合作用下的减振性能及参数影响进行了研究,并与传统TMD进行了对比。结果表明,所提控制装置能通过对结构响应的实时追踪适时调节阻尼器的控制参数,相比传统TMD有更佳的减振性能和适应性。参数分析表明,增大阻尼器质量比是提升MRE-PTMD工作性能的有效途径,通过对阻尼器质量比及碰撞参数的合理设计可在不过多影响减振效果的情况下实现对MRE的保护及控制装置小型化。展开更多
对隧道、桥梁结构和沿线建筑而言,浮置板减振性能优异,但其对轨道板及其上部结构的耗能能力有限。针对此问题,将调谐质量粒子阻尼技术应用于轨道交通振动控制领域,提出一种基于调谐质量粒子阻尼器(Tuned Mass Particle Damper,TMPD)的...对隧道、桥梁结构和沿线建筑而言,浮置板减振性能优异,但其对轨道板及其上部结构的耗能能力有限。针对此问题,将调谐质量粒子阻尼技术应用于轨道交通振动控制领域,提出一种基于调谐质量粒子阻尼器(Tuned Mass Particle Damper,TMPD)的耗能型钢弹簧浮置板结构。基于调谐质量阻尼器(Tuned Mass Damper,TMD)及粒子阻尼理论,利用1:1浮置板轨道进行室内试验,通过落轴试验研究调谐质量粒子阻尼器安装前后钢弹簧浮置板轨道动力学特性。研究结果表明:TMPD能显著降低浮置板轨道在固有频率11.7 Hz附近的振动响应,浮置板加速度分频振级损失最大可达11.9 dB;安装TMPD的耗能型钢弹簧浮置板轨道从钢轨到地面的振动衰减最大可达23.6 dB,表明其具有优异的隔振效果;进行Z振级评价分析可得,耗能型钢弹簧浮置板Z振级约降低5 dB,在保证隔振效率基础上,调谐质量粒子阻尼器可提高浮置板轨道的耗能能力。展开更多
近海环境复杂多变,风和波浪的综合载荷会对浮式风力涡轮机平台和塔顶产生较大振动,严重威胁风力涡轮机系统的结构安全。为了应对这一挑战,在驳船浮式风力涡轮机的机舱内安装了一个调谐质量阻尼器(tuned mass damper,TMD),并通过采用H∞...近海环境复杂多变,风和波浪的综合载荷会对浮式风力涡轮机平台和塔顶产生较大振动,严重威胁风力涡轮机系统的结构安全。为了应对这一挑战,在驳船浮式风力涡轮机的机舱内安装了一个调谐质量阻尼器(tuned mass damper,TMD),并通过采用H∞控制算法利用主动驱动力形成混合质量阻尼器(hybrid mass damper,HMD)。通过仿真比较了无控制、被动控制和H∞控制的效果,结果表明H∞控制能有效减小平台纵向角度和塔顶纵向位移,抑振效果明显。展开更多
基金The National Natural Science Foundation of China(No10772121)the Med-Science Cross Research Foundation of Shanghai Jiao-tong University (NoYG2007MS14)
文摘Aiming at a kind of middle ear implant（MEI）, the driving voltage of a piezoelectric floating mass actuator is analyzed using a 0. 7Pb （Mg1/3Nb2/3） O3-0. 3PbTiO3 （ PMN- 30% PT）stack as a new type of vibrator. For the purpose of facilitating the analysis, a simplified coupling model of the ossicular chain and the piezoelectric actuator is constructed. First, a finite element model of a human middle ear is constructed by reverse engineering technology, and the validity of this model is confirmed by comparing the simulated motion of the stapes footplate obtained by this model with experimental measurements. Then the displacement impedance of the incus long process is analyzed, and a single mass-spring-damper equivalent model of the ossicular chain attached with the clamp is derived. Finally, a simplified coupling model of the ossicular chain and the piezoelectric actuator is established and used to analyze the driving voltage property of the actuator. The results show that the required driving voltage decreases with the increase in the frequency, and the maximum required driving voltage is 20. 9 V in the voice frequencies. However, in the mid-high frequencies where most sensorineural hearing loss occurs, the maximum required driving voltage is 3.8 V, which meets the low-voltage and low-power requirements of the MEI.
基金supported by National Natural Science Foundation of China(Grant No.10772121)
文摘To overcome some of the problems inherent in conventional heating aids such as low gain at high fi'equencies due to acoustic feedback,discomfort in occlusion of the extemal ear canal and so on,implantable middle ear hearing devices(IMEHDs)have been developed over the past two decades.For such kinds of IMEHDs,this paper presents the design of a floating mass piezoelectric actuator using a PMN-30%PT stack as a new type of vibrator.The proposed piezoelectric actuator consists of only three components of a piezoelectric stack,a metal case and a clamp.For the purpose of aiding the design of this actuator,a coupling biomechanics model of human middle ear and the piezoelectric actuator was constructed.This model was built based on a complete set of computerized tomography section images of a healthy volunteer's left ear by reverse engineering technology.The validity of this model was confirmed by comparing the motion of the tympanic membrane and stapes footplate obtained by this model with published experimental measurements on human temporal bones.It is shown that the designed actuator can be implanted on the incus long process by a simple surgical operation,and the stapes footplate displacement by its excitation at 10.5 V root-mean-square(RMS)voltage was equivalent to that from acoustic stimulation at 100 dB sound pressure level(SPL),which is adequate stimulation to the ossicular chain.The corresponding power consumption is 0.04 mW per volt of excitation at 1 kHz,which is low enough for the transducer to be used in an implantable middle ear device.
文摘考虑到海上浮式风机(floating offshore wind turbine,FOWT)因存在整体晃动导致背景响应强烈,在频域上有时表现为激励频率,且随激励频率的变化而变化,在使用传统调谐质量阻尼器(tuned mass damper,TMD)对其进行振动控制时出现频率失调和效果不佳等现象,该研究设计并提出了一种带碰撞的磁流变弹性体变刚度调谐质量阻尼器(magnetorheological elastomer-pounding tuned mass damper,MRE-PTMD)对FOWT实施半主动控制。在该控制装置中,利用MRE的刚度可调特性,通过半主动控制技术实现阻尼器频率的实时调节,保持对FOWT的最优控制,同时引入限位挡板对MRE材料加以保护并实现碰撞耗能。以驳船型FOWT为例,建立了包含控制装置的17自由度动力方程,对其在风浪联合作用下的减振性能及参数影响进行了研究,并与传统TMD进行了对比。结果表明,所提控制装置能通过对结构响应的实时追踪适时调节阻尼器的控制参数,相比传统TMD有更佳的减振性能和适应性。参数分析表明,增大阻尼器质量比是提升MRE-PTMD工作性能的有效途径,通过对阻尼器质量比及碰撞参数的合理设计可在不过多影响减振效果的情况下实现对MRE的保护及控制装置小型化。
文摘对隧道、桥梁结构和沿线建筑而言,浮置板减振性能优异,但其对轨道板及其上部结构的耗能能力有限。针对此问题,将调谐质量粒子阻尼技术应用于轨道交通振动控制领域,提出一种基于调谐质量粒子阻尼器(Tuned Mass Particle Damper,TMPD)的耗能型钢弹簧浮置板结构。基于调谐质量阻尼器(Tuned Mass Damper,TMD)及粒子阻尼理论,利用1:1浮置板轨道进行室内试验,通过落轴试验研究调谐质量粒子阻尼器安装前后钢弹簧浮置板轨道动力学特性。研究结果表明:TMPD能显著降低浮置板轨道在固有频率11.7 Hz附近的振动响应,浮置板加速度分频振级损失最大可达11.9 dB;安装TMPD的耗能型钢弹簧浮置板轨道从钢轨到地面的振动衰减最大可达23.6 dB,表明其具有优异的隔振效果;进行Z振级评价分析可得,耗能型钢弹簧浮置板Z振级约降低5 dB,在保证隔振效率基础上,调谐质量粒子阻尼器可提高浮置板轨道的耗能能力。
文摘近海环境复杂多变,风和波浪的综合载荷会对浮式风力涡轮机平台和塔顶产生较大振动,严重威胁风力涡轮机系统的结构安全。为了应对这一挑战,在驳船浮式风力涡轮机的机舱内安装了一个调谐质量阻尼器(tuned mass damper,TMD),并通过采用H∞控制算法利用主动驱动力形成混合质量阻尼器(hybrid mass damper,HMD)。通过仿真比较了无控制、被动控制和H∞控制的效果,结果表明H∞控制能有效减小平台纵向角度和塔顶纵向位移,抑振效果明显。
