共查询到20条相似文献,搜索用时 10 毫秒
1.
Chabok HR Cannata JM Kim HH Williams JA Park J Shung KK 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(1):206-214
This paper reports the design, fabrication, and characterization of a 1-3 composite annular-array transducer. An interdigital bonded (IB) 1-3 composite was prepared using two IB operations on a fine-grain piezoelectric ceramic. The final composite had 19-μm-wide posts separated by 6-μm-wide polymer kerfs. A novel method to remove metal electrodes from polymer portions of the 1-3 composite was established to eliminate the need for patterning and aligning the electrode on the composite to the electrodes on a flexible circuit. Unloaded epoxy was used for both the matching and backing layers and a flexible circuit was used for interconnect. A prototype array was successfully fabricated and tested. The results were in reasonable agreement with those predicted by a circuit-analogous model. The average center frequency estimated from the measured pulse-echo responses of array elements was 33.5 MHz and the -6-dB fractional bandwidth was 57%. The average insertion loss recorded was 14.3 dB, and the maximum crosstalk between the nearest-neighbor elements was less than -37 dB. Images of a wire phantom and excised porcine eye were obtained to show the capabilities of the array for high-frequency ultrasound imaging. 相似文献
2.
The performance of 3-3 connectivity composite piezoelectric transducers is discussed. This type of transducer has been successfully used in ultrasonic imaging (frequency range: 150~600 kHz). Using a simple hardware system, this type of transducer can recognize a very thin aluminum plank (6 mm in thickness) in water, and it can clearly recognize a multilayer body. 相似文献
3.
Samarium and manganese-doped lead titanate ceramic fiber/epoxy 1-3 composite for high-frequency transducer application 总被引:1,自引:0,他引:1
Li K Chan HL Choy CL 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2003,50(10):1371-1376
Samarium- (Sm) and manganese- (Mn) doped lead titanate ceramic fibers with a diameter of 35 /spl mu/m were prepared using a sol-gel method. The X-ray diffraction pattern shows that the fibers have a pure perovskite structure. The 1-3 composite disks with a thickness of 31-41 /spl mu/m and with ceramic volume fraction of /spl sim/0.68 have been prepared using the samarium and manganese doped lead titanate (PSmT) fibers. The resonance characteristics of the poled composite disks were measured. A focused transducer was fabricated using a concave 1-3 composite disk with nonuniform thickness in order to enhance its bandwidth. The insertion loss (IL), pulse-echo response and frequency spectrum of the composite transducer were measured. The center frequency of the transducer was /spl sim/31 MHz with a -3 dB bandwidth of /spl sim/123% and a low IL of 29.3 dB. 相似文献
4.
水声高频换能器在水声领域具有广泛运用,然而常规厚度振动高频换能器在高频段存在强烈的高次径向耦合振动,制作出的换能器出现了阻抗曲线杂乱,相位一致性差,电声效率低的问题。设计制作了一种单一振动模态的换能器,通过将常规厚度振动换能器陶瓷片切割成密排矩形颗粒,再用环氧树脂将切缝填充满。制作两片直径为55mm的准1-3复合材料,由该材料制作的换能器谐振频率为293kHz,谐振点阻抗50,3dB阻抗带宽23.5 kHz,3dB开角为5.75°,50W电功率输出声源级达到217.5dB。通过该工艺可以消除高频厚度振动换能器的高次径向耦合振动,提高高频厚度振动换能器的电声转换效率和一致性,并能实现批量制作,为高频换能器在水声领域的广泛运用提供了新的手段。 相似文献
5.
The development of a 200-kHz air ultrasonic transducer that consists of a piezoceramic disc and metal housing, the latter acting as a radiating membrane, is discussed. Theoretical analysis of the axially symmetric transducer structure is based upon the finite-element method. Calculations of the resonance frequencies, corresponding transducer deformations and input electrical admittance are performed using triangular ring elements with six degrees of freedom. Measured values on experimentally built transducers show good agreement with theory. 相似文献
6.
A cylindrical traveling wave ultrasonic motor using a circumferential composite transducer 总被引:1,自引:0,他引:1
Liu Y Liu J Chen W 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2011,58(11):2397-2404
This paper intends to present and verify a new idea for constructing traveling wave ultrasonic motors that may effectively avoid the drawbacks of conventional traveling wave motors using bonded PZT plates as the exciting elements. In the configuration of the motor's stator, a composite sandwich type transducer is used to excite a traveling wave in a cylinder with two cantilevers as the coupling bridges between the transducer and the cylinder. The design process of the stator is described using the FEM modal analysis method, and the establishment of traveling wave on the cylindrical stator was simulated by FEM transient analysis. To verify the theoretical analysis results, a laser Doppler scanner was employed to test the mode shapes of a prototype stator excited by the longitudinal and bending vibrations respectively. Finally, to validate the design idea, a prototype motor was fabricated and tested; the typical output features are no-load speed of 156 rpm and maximum torque of 0.75 N·m under exciting voltages of 70 V(rms) applied to excite the longitudinal vibration of the transducer and 200 V(rms) applied to excite the bending vibration. 相似文献
7.
A novel method for the in-situ repair of composite sandwich structures using microvascular networks and cyanoacrylate (CA) adhesive systems has been presented. Upon a damage event, the vascules become ruptured, providing a route for the introduction of adhesive directly into the damage site. The efficacy of the two repair agents was first assessed under static and fatigue conditions using a modified double cantilever beam (DCB) method. Once baseline fracture behaviour of the cyanoacrylates has been established, they were further assessed by injection into a series of pre-damaged T-joint specimens. The presence of the vasculature was shown to have no detrimental impact on mechanical performance, whilst both of the cyanoacrylates were shown to be highly effective in the recovery of stiffness and ultimate strength of the T-joint specimens. 相似文献
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10.
Y. Cui D. Liu M. Y. Fan G. P. Deng L. X. Sun Y. Zhang 《Materials Science & Technology》2020,36(4):425-433
ABSTRACT The microstructure and mechanical properties of explosively welded TA1/3A21 composite plate were studied. The results suggested that the bonding interface had a wavy appearance, and two types of Ti–Al solid solutions were found in the crest region. Most of the interfaces had a thin diffusion layer with a thickness of approximately 3?µm, and no brittle intermetallic compounds were formed. The interface of the explosively welded TA1 Ti/3A21 Al composite plate exhibited reliable shear and bending properties. The propagation of the facile cracks initiated at the Ti–Al solid solution/Al interface, and the Ti–Al solid solution region at the vortex could be terminated by the Ti matrix. In addition, the complex bonding interface structure inhibited the crack propagation along the interface. 相似文献
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12.
Finite-element analysis of 1-3 composite transducers 总被引:1,自引:0,他引:1
Hossack JA Hayward G 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1991,38(6):618-629
The vibrational and electromechanical characteristics of a wide range of 1-3 composite structures, comprising ceramic pillars aligned within a polymer phase, are considered using finite-element analysis. The influence of pillar geometry, ceramic volume fraction, and pillar orientation is described in terms of overall transduction efficiency. It is shown that the finite-element method provides a versatile means of analysis and the results obtained permit a set of useful design guidelines to be developed. In general, a small pillar aspect ratio and a relatively high volume fraction provides the most satisfactory performance, in terms of electromechanical efficiency and uniformity of thickness dilation. 相似文献
13.
采用磁控溅射工艺以Cu、Ag为靶材在1-3型压电复合材料表面制备电极.研究了两种金属材料的溅射镀膜工艺,系统地分析了溅射功率对金属沉积速率、电极导电性能及附着力的影响.结果表明,两种金属的沉积速率随溅射功率的增加呈线性增加,电极方阻及电阻率均随功率增大而减小,溅射功率为100W时电极的附着力较好. 相似文献
14.
In this paper, an analysis for active constrained layer damping (ACLD) of rotating composite beams undergoing geometrically non linear vibrations has been carried out. Commercially available vertically/obliquely reinforced 1-3 piezoelectric composite (PZC) material has been used as the material of the constraining layer of the ACLD treatment. A finite element (FE) model has been derived to carry out the analysis. The substrate beam is considered thin and hence, first order shear deformation theory (FSDT) and von-Karman type nonlinear strain–displacement relations are used to derive the coupled electromechanical nonlinear FE model. The rotary effect has been suitably modelled by incorporating extensional strain energy due to centrifugal force. The Golla–Hughes–McTavish method has been employed to model the constrained viscoelastic layer of the ACLD treatment in the time domain. The numerical responses revealed that the ACLD treatment with 1-3 PZC constraining layer efficiently performs the task of active damping of geometrically nonlinear vibrations of the rotating composite beams. The effects of the fibre orientation angles of the angle-ply substrate beams and the 1-3 PZC constraining layer on the ACLD of the geometrically nonlinear vibrations have been investigated. Also, the effect of the thickness variations of the 1-3 PZC layer and the viscoelastic constrained layer on the damping characteristics of the overall rotating composite beams has been studied. 相似文献
15.
Mehdi Kalantari Mohammad Rahim NamiMohammad Hasan Kadivar 《International Journal of Impact Engineering》2010
The present paper deals with the optimization of composite sandwich panels subjected to low-velocity impact using advanced genetic algorithm (GA). Equivalent multi degree-of-freedom system is used to predict the contact force history and deformation response of the sandwich panels. Also, analytical solutions are used to determine the impact force and velocity at damage initiation. The GA's objective is to maximize the strength of panel by varying the ply angles of the facesheets. The results show that the stacking sequence of facesheets plays an important role in the strength of the composite sandwich panels subjected to impact loading. 相似文献
16.
Modeling 1-3 composite piezoelectrics: thickness-mode oscillations 总被引:11,自引:0,他引:11
Smith WA Auld BA 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1991,38(1):40-47
A simple physical model of 1-3 composite piezoelectrics is advanced for the material properties that are relevant to thickness-mode oscillations. This model is valid when the lateral spatial scale of the composite is sufficiently fine that the composite can be treated as an effective homogeneous medium. Expressions for the composite's material parameters in terms of the volume fraction of piezoelectric ceramic and the properties of the constituent piezoelectric ceramic and passive polymer are derived. A number of examples illustrate the implications of using piezocomposites in medical ultrasonic imaging transducers. While most material properties of the composite roughly interpolate between their values for pure polymer and pure ceramic, the composite's thickness-mode electromechanical coupling can exceed that of the component ceramic. This enhanced electromechanical coupling stems from partially freeing the lateral clamping of the ceramic in the composite structure. Their higher coupling and lower acoustic impedance recommend composites for medical ultrasonic imaging transducers. The model also reveals that the composite's material properties cannot be optimized simultaneously; tradeoffs must be made. Of most significance is the tradeoff between the desired lower acoustic impedance and the undesired smaller electromechanical coupling that occurs as the volume fraction of piezoceramic is reduced. 相似文献
17.
Modeling 1-3 composite piezoelectrics: hydrostatic response 总被引:1,自引:0,他引:1
A simple physical model of 1-3 composite piezoelectrics that was advanced for the material properties relevant to thickness-mode oscillations is extended to address the hydrostatic response. The model is valid when the lateral spatial scale of the composite is sufficiently fine that the composite can be treated as an effective homogeneous medium. Expressions are derived for the composite's material parameters in terms of the volume fraction of piezoelectric ceramic and the properties of the constituent piezoelectric ceramic and passive polymer. The results are similar to those derived by Haun and Newnham (1983, 1986) using a parallel-series connectivity model. The model is illustrated by analyzing composites made from conventional PZT5 and anisotropic modified lead titanate piezoelectric ceramics. For PZT5, the composite structure enhances its hydrostatic charge coefficient, hydrostatic voltage coefficient, hydrophone figure of merit, and hydrostatic coupling coefficient, while three of these quantities fall short of their pure ceramic values in the modified lead titanate composites. The shortfall is due to an enhanced composite that arises from lateral stress on the polymer being transferred to a longitudinal stress along the ceramic rods by the Poisson effect in the polymer, thus producing a charge through the ceramic's d(33). 相似文献
18.
Certon D Guyonvarch J Férin G Patat F 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2006,53(12):2471-2480
An analytical model is presented to achieve simultaneous prediction of the elementary electroacoustic response and directivity pattern of a one-dimensional (1-D) piezocomposite array. The theoretical approach was based on guided wave theory in a multilayered structure in which the 1-3 piezocomposite material is considered as a homogeneous piezoelectric plate. A matrix method was applied to simulate the displacement fields generated at the surface of the array when one element was excited with an electrical pulse. A test device was manufactured, then characterized through measurements of displacement performed with an interferometric laser probe when the array vibrated in air and in water. The experimental results are presented and compared with theory. 相似文献
19.
A model for the hydrostatic pressure response of a 1-3 composite 总被引:1,自引:0,他引:1
Montgomery R.E. Richard C. 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1996,43(3):457-466
An analytical model has been developed for predicting the mechanical response of a composite cylinder that is composed of a solid right circular cylinder of one material surrounded by a cylindrical tube composed of some other material. It is assumed that there is no slippage at the boundary between the two phases. The model employs, throughout, the exact equations of linear elasticity and, thus, provides a solution that is exact for the specific boundary conditions that are imposed, In this paper, the specific case of hydrostatic pressure applied to the surface of the composite cylinder is discussed, The model yields the displacement and stress fields throughout the entire structure. The model was verified by comparing the results with a finite element model at several surfaces and interfaces in the structure, The model can be readily applied to the analysis of passive composite structures as well as to some of the recent active materials such as 1-3 piezocomposites 相似文献
20.
The conventional manufacturing of composite sandwich structures is completed by adhesive bonding separately prepared composite faces to cores. The joining process during sandwich fabrication is a most difficult process, which requires strict quality control. However, the joining process can be eliminated when the sandwich structures are manufactured by the co-cure method inside a mold using the large difference of coefficient of thermal expansion between foam cores and steel mold.
In this work, the robot hands and wrists for handling large LCD glass panel displays were designed and manufactured using the co-cure method. Considering the non-linear thermal expansion properties of the foam during co-cure manufacturing, the pressure generated inside a mold was analyzed and the required pre-compression strain of the foam for sandwich beams was determined for enough consolidation. Finally, the composite sandwich robot hands and wrists were co-cure manufactured and the deflections of hands were measured under the weight of large LCD glass panel. 相似文献