Study on Novel Relaxor Ferroelectric Single Crystal PMNT/Epoxy Composite

2013 ◽  
Vol 475-476 ◽  
pp. 1257-1261
Author(s):  
Guang Li ◽  
Gui Dong Luan ◽  
Hao Qu
Keyword(s):  
Epoxy Composite ◽  
Theoretical Calculations ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Relaxor Ferroelectric ◽  
Piezoelectric Composite ◽  
Mechanical And Thermal Properties ◽  
Piezoelectric Crystal ◽  
Piezoelectric Composites ◽  
Piezoelectric Phase

Use relaxor ferroelectric single crystals PMNT as piezoelectric phase, epoxy resin as a non-piezoelectric phase material, take the cutting - filling method fabricated piezoelectric composite. Its structure character is achieved 1-3 type piezoelectric composites and piezoelectric crystal substrate composite again inseries by the integration, the composite horizontal and vertical bracket to be supported by piezoelectric crystal frame, it has a good impact resistance and affected by changes in ambient temperature characteristics. This composite material both has the advantages of 1-3 type composites, and has stable mechanical and thermal properties. Based on R.E.Newnhams series-parallel theory, combined with the structural characteristics of this composite, given the formula of piezoelectric composites density, piezoelectric constant, and dielectric constant. Fabricated the PMNT / epoxy composites and piezoelectric PZT / epoxy piezoelectric composite materials samples, which have the same scale, the same structural parameters. The experimental results show that, the piezoelectric composite test parameter values match theoretical calculations. The PMNT/epoxy composite has batter function than PZT/epoxy composite.

Study on Novel Relaxor Ferroelectric Single Crystal PMNT/Epoxy Composite Transducer Array

2014 ◽  
Vol 511-512 ◽  
pp. 74-77 ◽  
Author(s):  
Guang Li ◽  
Gui Dong Luan
Keyword(s):  
Single Crystals ◽  
Epoxy Composite ◽  
Relaxor Ferroelectric ◽  
Piezoelectric Composite ◽  
Micro Structure ◽  
Transducer Array ◽  
Piezoelectric Phase ◽  
Filling Method ◽  
Ferroelectric Single Crystal ◽  
Higher Sensitivity

Using relaxor ferroelectric single crystals PMNT as piezoelectric phase and epoxy resin as a non-piezoelectric phase material, the piezoelectric composite is fabricated with the cutting - filling method. Using the same micro-structure parameters and the same process, the piezoelectric composite is prepared with the conventional piezoelectric ceramic PZT5 as piezoelectric phase material. The transducer array is respectively assembled with the PMNT /epoxy composites and PZT5/epoxy piezoelectric composite materials. Experimental results show that the relaxor ferroelectric single crystals PMNT / epoxy composite transducer array has higher sensitivity and less resonant impedance than PZT5/epoxy piezoelectric composite transducer array.

scholarly journals Optimization and simulation analysis of structure parameters of OPCM ultrasonic longitudinal wave actuating element

2019 ◽  
Vol 26 (1) ◽  
pp. 175-182
Author(s):  
Ziping Wang ◽  
Yangchun Ye ◽  
Zhujie Bao ◽  
Hao Ge
Keyword(s):  
Longitudinal Wave ◽  
Simulation Analysis ◽  
Piezoelectric Composite ◽  
Piezoelectric Composites ◽  
Mechanical And Electrical Properties ◽  
Piezoelectric Phase ◽  
Ultrasonic Phased Array ◽  
Wave Drive ◽  
Optimization And Simulation ◽  
Relationship Of

AbstractThe force-electric coupling relationship of the mechanical and electrical properties of piezoelectric composites has been the main factor in the research and development of piezoelectric composites in practical application. A novel orthotropic piezoelectric composite material (OPCM) element is studied in this paper. The properties of the piezoelectric phase and the polymer phase and the influence of the geometrical dimensions of the OPCM on the longitudinal wave drive element are analyzed from the perspective of mechanics and electric power, respectively, and the structural design is optimized. This provides a theoretical basis for the development of OPCM and of new longitudinal ultrasonic phased array actuators.

Finite Element Analysis of 1-3-2 Piezoelectric Composite Resonance Frequency Characteristics

2014 ◽  
Vol 511-512 ◽  
pp. 70-73
Author(s):  
Gui Dong Luan ◽  
Guang Li
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Material ◽  
Resonant Frequency ◽  
Theoretical Calculations ◽  
Structural Parameters ◽  
Piezoelectric Composite ◽  
The Finite Element Method ◽  
Element Analysis ◽  
The Relationship

Taking the finite element method, the resonant frequency of the 1-3-2 type piezoelectric composites is calculated by finite element analysis software ANSYS. The relationship between the thickness of the composite material and its resonant frequency of admittance characteristics are calculated. The different structural parameters 1-3-2 type piezoelectric composite material samples are designed and prepared. The results show that the theoretical calculations are well matched with experimental results .

scholarly journals Coupled Fluid–Solid Numerical Simulation for Flow Field Characteristics and Supporting Performance of Flexible Support Cylindrical Gas Film Seal

Aerospace ◽  
2021 ◽  
Vol 8 (4) ◽  
pp. 97
Author(s):  
Junfeng Sun ◽  
Meihong Liu ◽  
Zhen Xu ◽  
Taohong Liao ◽  
Xiangping Hu ◽  
...  
Keyword(s):  
Flow Field ◽  
Film Thickness ◽  
Fluid Dynamic ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
High Rotational Speed ◽  
Flexible Support ◽  
Flow Field Characteristics

A new type of cylindrical gas film seal (CGFS) with a flexible support is proposed according to the working characteristics of the fluid dynamic seal in high-rotational-speed fluid machinery, such as aero-engines and centrifuges. Compared with the CGFS without a flexible support, the CGFS with flexible support presents stronger radial floating characteristics since it absorbs vibration and reduces thermal deformation of the rotor system. Combined with the structural characteristics of a film seal, an analytical model of CGFS with a flexible wave foil is established. Based on the fluid-structure coupling analysis method, the three-dimensional flow field of a straight-groove CGFS model is simulated to study the effects of operating and structural parameters on the steady-state characteristics and the effects of gas film thickness, eccentricity, and the number of wave foils on the equivalent stress of the flexible support. Simulation results show that the film stiffness increases significantly when the depth of groove increases. When the gas film thickness increases, the average equivalent stress of the flexible support first decreases and then stabilizes. Furthermore, the number of wave foils affects the average foils thickness. Therefore, when selecting the number of wave foils, the support stiffness and buffer capacity should be considered simultaneously.

The 3-D Numerical Simulation of Heat Transfer Process of Finned Copper Tube

2011 ◽  
Vol 393-395 ◽  
pp. 412-415
Author(s):  
Jian Hua Zhong ◽  
Li Ming Jiang ◽  
Kai Feng
Keyword(s):  
Heat Transfer ◽  
Transfer Process ◽  
Theoretical Calculations ◽  
Structural Parameters ◽  
Convection Heat Transfer ◽  
Heat Transfer Process ◽  
Finned Tube ◽  
Copper Tube ◽  
Central Air Conditioning ◽  
Fin Thickness

In this article, finned copper tube used in the central air conditioning was acted as the discussed object. According to the combination with actual processing and theoretical calculations, Five finned tube was selected with typical structural parameters, and established their entity model using Pro/E, then the heat transfer process of finned tube was simulated through the ANSYS, the effect of the fin height, fin thickness and other structure parameters to the heat transfer enhancement of finned tube was researched. Meantime the efficiency of the heat transfer under different convection heat transfer coefficient was also studied.

A Probabilistic High-Pressure Zone Model of Dynamic Ice Structure Interactions and Associated Ice-Induced Vibrations

2021 ◽  
Author(s):  
Ridwan Hossain ◽  
Rocky Taylor ◽  
Lorenzo Moro
Keyword(s):  
High Pressure ◽  
Theoretical Calculations ◽  
Structural Parameters ◽  
Structural Response ◽  
Zone Model ◽  
Modelling Framework ◽  
Lower Amplitude ◽  
Average Strain Rate ◽  
High Pressure Zone ◽  
Lock In

Abstract During ice-structure interactions that are dominated by ice compressive failure, the majority of the ice loads are transmitted through localized contact regions known as high-pressure zones (hpzs). This paper presents a probabilistic modelling framework for dynamic ice-structure interaction based on the mechanics of hpzs. Individual hpzs are modelled as a nonlinear spring-damper system where the stiffness is modelled as a function of nominal strain, with the degree of softening depending on the average strain-rate. Both spalling and crushing failure mechanisms were assessed in the context of periodical sinusoidal response. For spall dominated failure, the model structure showed presence of frequency lock-in in the speed range of 100–125mm/s, beyond which the failure was found to be random in nature with lower amplitude of structural response. The amplitude was also found to be significantly influenced by structural parameters with structural damping having the highest contribution. For pure crushing, an estimated equilibrium layer thickness based on theoretical calculations also showed presence of frequency lock-in. The work highlights the importance of understanding the interplay between these mechanisms, as well as the role of ice conditions and structural parameters on the processes that dominate an interaction.

Synthetic Transfer Zone Characterization Using Seismic Attributes: An Example from the Parihaka Fault System in the Taranaki Basin, New Zealand.

2021 ◽  
pp. 1-73
Author(s):  
Pierre Karam ◽  
Shankar Mitra ◽  
Kurt Marfurt ◽  
Brett M. Carpenter
Keyword(s):  
New Zealand ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Seismic Attributes ◽  
Fault System ◽  
Structural Interpretation ◽  
Transfer Zones ◽  
Seismic Characterization ◽  
The Individual ◽  
Transfer Zone

Synthetic transfer zones develop between fault segments which dip in the same direction, with relay ramps connecting the fault blocks separated by the different fault segments. The characteristics of the transfer zones are controlled by the lithology, deformation conditions, and strain magnitude. The Parihaka fault is a NE-SW trending set of three major en-echelon faults connected by relay ramps in the Taranaki Basin, New Zealand. The structure in the basin is defined by extension during two episodes of deformation between the late Cretaceous and Paleocene and between the Late Miocene and recent. To better understand the evolution of a synthetic transfer zone, we study the geometry and secondary faulting between the individual fault segments in the Parihaka fault system using structural interpretation of 3D seismic data and seismic attributes. This interpretation allows for a unique application of seismic attributes to better study transfer zones. Seismic attributes, including coherence, dip, and curvature are effective tools to understand the detailed geometry and variation in displacement on the individual faults, the nature of secondary faulting along the transfer zones, and the relationship between the faults and drape folds. Seismic characterization of the fault system of Miocene to Pliocene age horizons highlights variations in the degree of faulting, deformation, and growth mechanism associated with different stages of transfer zone development. Coherence, dip, and curvature attributes show a direct correlation with structural parameters such as deformation, folding, and breaching of relay ramps.. All three attributes enhance the visualization of the major and associated secondary faults and better constrain their tectonic history. The observed correlation between seismic attributes and structural characteristics of transfer zones can significantly improve structural interpretation and exploration workflow.

Periodicity of Piezoelectric Ceramic Rods on Properties of 1-3 Type Cement Based Piezoelectric Composite

2010 ◽  
Vol 123-125 ◽  
pp. 161-164
Author(s):  
Dong Yu Xu ◽  
Shi Feng Huang ◽  
Chao Ju ◽  
Zong Zhen Zhang ◽  
Xin Cheng ◽  
...  
Keyword(s):  
Piezoelectric Ceramic ◽  
Electromechanical Coupling ◽  
Resonant Mode ◽  
Piezoelectric Composite ◽  
Electromechanical Coupling Coefficient ◽  
Frequency Spectra ◽  
Piezoelectric Composites ◽  
Periodic Composites ◽  
Periodic Composite ◽  
Periodic Arrangement

Periodic and non-periodic 1-3 type cement based piezoelectric composites were fabricated by cut and filling technique, using P(MN)ZT ceramic as functional material and cement as matrix. The influences of periodicity of piezoelectric ceramic rods in the composites on electrical properties of all the composites were discussed. The results show that the non-periodic composites have larger dielectric factor and piezoelectric strain constant than those of the periodic composite. The impedance-frequency spectra analysis indicates that the non-periodic arrangement of ceramic rods can effectively restrict the lateral structural mode of the composite, accordingly reduces the coupling resonant between the thickness resonant mode and lateral resonant mode. The thickness electromechanical coupling coefficient of non-periodic composites is larger than that of the periodic composite. With increasing the non-periodic level of P(MN)ZT ceramic in the composites, the mechanical quality factor of the composites increases gradually. Therefore, 1-3 type cement based piezoelectric composites with different special abilities can be obtained by varying the periodic arrangement of P(MN)ZT ceramic rods in the composites.

Abstract TP436: Dysfunctional Cerebral Neovascularization And Remodeling Patterns In Obese And Lean Models Of Type 2 Diabetes

Stroke ◽  
2013 ◽  
Vol 44 (suppl_1) ◽  
Author(s):  
Roshini Prakash ◽  
Maribeth Johnson ◽  
Susan C Fagan ◽  
Adviye Ergul
Keyword(s):  
Type 2 Diabetes ◽  
Glycemic Control ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Volume Density ◽  
3 Dimensional ◽  
Gk Rats ◽  
Dimensional Reconstruction ◽  
Branch Density

We previously reported intense pial cerebral collateralization and arteriogenesis in a mild and lean model of type 2 diabetes, Goto-Kakizaki (GK) rats. Further 3-dimensional fluroscein (FITC) imaging studies revealed regional differences in increased cerebral neovascularization which was associated with poor vessel wall maturity. Building upon these findings, the goals of this study were a) to compare and contrast this pathological neovascularization pattern in db/db mice and GK models of diabetes, and b) determine the effect of glycemic control on erratic cerebral neovascularization. Total vascular volume, density and surface area as well as structural parameters including microvessel/macrovessel ratio, non-FITC perfusing vessel abundance, penetrating arteriole (PA) branching density and diameter, and tortuosity were measured by 3 dimensional reconstruction of FITC stained vasculature using Z-stacked images obtained with confocal microscopy. Lean GK rats exhibited an increase in both micro and macrovessel density, non-perfusing vessel abundance, branch density, diameter and tortuosity. Glycemic control with metformin prevented these changes. Obese db/db mice, on the other hand, showed an increase in only microvascular density but this was not associated with an increase in non-FITC perfusing vessels. PA branch density was higher than controls but branch diameter was reduced. Diabetes also promoted astrogliosis. These results suggests that type 2 diabetes leads to cerebral neovascularization and remodeling but structural characteristics of newly formed vessels differ between lean and obese models that have mild or severe hyperglycemia, respectively. The prevention of dysfunctional cerebral neovascularization by early glucose control suggests that hyperglycemia is a mediator of this response. N=4-8 * p≤ 0.05, ** p≤ 0.005 *** 0.0005

Optimal Design of Composite Material Maintenance Structure for Aircraft Based on ANSYS Workbench

2021 ◽  
Vol 871 ◽  
pp. 216-221
Author(s):  
Jing Tao Dai ◽  
Pei Zhong Zhao ◽  
Hong Bo Su ◽  
Hao Dong Liu ◽  
Yu Bo Wang ◽  
...  
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Optimal Design ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Element Model ◽  
Composite Cement ◽  
Composite Patch ◽  
Length Width ◽  
Ansys Workbench

Composite material is widely used to maintain damaged structures of aircraft. The 3D finite element model of composite cement maintenance for aircraft is established by finite element method software ANSYS Workbench. The structural characteristics and usage status of the composite cement maintenance model is analyzed, and then the optimal structural parameters of the composite patch are obtained, including the length, width and thickness. The results show that the composite cement maintenance method could effectively restore the rigidity, and improve the strength of the structure. Furthermore, the optimal design for composite patch ensures safety of aircraft, economics of maintenance, and operability of repair methods.

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