scholarly journals Dynamic Properties of Microresonators with the Bionic Structure of Tympanic Membrane

Sensors ◽  
2020 ◽  
Vol 20 (23) ◽  
pp. 6958
Author(s):  
Yongpeng Tai ◽  
Kai Zhou ◽  
Ning Chen
Keyword(s):  
Tympanic Membrane ◽  
Dynamic Properties ◽  
Structural Characteristics ◽  
Structural Parameters ◽  
Geometric Model ◽  
Effective Area ◽  
The Finite Element Method ◽  
Vibration Displacement ◽  
Bionic Structure ◽  
Contour Surface

The structure of a microresonator will affect the vibration characteristics and the performance of the system. Inspired by the structural characteristics of the human tympanic membrane, this paper proposed a microresonator with the bionic structure of a tympanic membrane. The structure of a tympanic membrane was simplified to a regular shape with three structural parameters: diameter, height, and thickness. To imitate the tympanic membrane, the contour surface of the bionic structure was modeled based on the formula of transverse vibration mode of a circular thin plate. The geometric model of the bionic structure was established by using the three structural parameters and the contour surface equation. The dynamic properties of the bionic model were studied by the finite element method (FEM). We discuss the modal characteristics of the bionic structure and study the effect of structural parameters and scale on the dynamic properties. The advantages of the bionic structure were investigated by a comparison with circular plate microresonators. The results illustrate that the bionic structure can significantly improve the resonant frequency and have a much larger effective area of vibration displacement.

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.

scholarly journals Pose Measurement for Unmanned Aerial Vehicle Based on Rigid Skeleton

2021 ◽  
Vol 11 (4) ◽  
pp. 1373
Author(s):  
Jingyu Zhang ◽  
Zhen Liu ◽  
Guangjun Zhang
Keyword(s):  
Measurement Errors ◽  
Structural Characteristics ◽  
Geometric Model ◽  
Formation Flight ◽  
Depth Information ◽  
Feature Points ◽  
Feature Point Extraction ◽  
Aerial Vehicle ◽  
Uav Navigation ◽  
Rigid Skeleton

Pose measurement is a necessary technology for UAV navigation. Accurate pose measurement is the most important guarantee for a UAV stable flight. UAV pose measurement methods mostly use image matching with aircraft models or 2D points corresponding with 3D points. These methods will lead to pose measurement errors due to inaccurate contour and key feature point extraction. In order to solve these problems, a pose measurement method based on the structural characteristics of aircraft rigid skeleton is proposed in this paper. The depth information is introduced to guide and label the 2D feature points to eliminate the feature mismatch and segment the region. The space points obtained from the marked feature points fit the space linear equation of the rigid skeleton, and the UAV attitude is calculated by combining with the geometric model. This method does not need cooperative identification of the aircraft model, and can stably measure the position and attitude of short-range UAV in various environments. The effectiveness and reliability of the proposed method are verified by experiments on a visual simulation platform. The method proposed can prevent aircraft collision and ensure the safety of UAV navigation in autonomous refueling or formation flight.

A Study of the Anchor Effect Based on Structural Parameters of Flexible Pressurized Anchor and Pressure from Surrounding Rock

2011 ◽  
Vol 71-78 ◽  
pp. 4634-4637
Author(s):  
Tian Lin Cui ◽  
Jing Kun Pi ◽  
Yong Hui Liu ◽  
Zhen Hua He
Keyword(s):  
Structural Parameters ◽  
Structural Features ◽  
Surrounding Rock ◽  
Design Parameters ◽  
Optimized Design ◽  
Anchor Effect ◽  
The Finite Element Method ◽  
Anchor System ◽  
New Type ◽  
Stress Relation

In order to optimize the design of flexible pressurized anchor, this paper gives a further analysis on structural features of the new type of flexible pressurized anchor and carries out a contact analysis on anchor system by using the finite element method. It calculates as well as researches the contact stress relation of interactional anchor rod and surrounding rock under the circumstance of anchoring, obtaining the law of all major design parameters of anchor rod structure and pressure from surrounding rock influencing the anchoring performance and arriving at the conclusion that the anchor rod is adapted to various conditions of surrounding rock. They not only serve as important references for optimized design and application of anchor rod, but also provide a basis for the experiment of new type of anchor rod.

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.

The Dynamic Characteristics of Rigid Frame Single-Rib Arch Bridge

2013 ◽  
Vol 368-370 ◽  
pp. 1426-1430
Author(s):  
Li Xiong Gu ◽  
Rong Hui Wang
Keyword(s):  
Dynamic Characteristics ◽  
Bending Strength ◽  
Dynamic Properties ◽  
Structural Parameters ◽  
Bending Stiffness ◽  
Torsional Stiffness ◽  
Lateral Stiffness ◽  
Arch Bridge ◽  
Vertical Stiffness ◽  
Rigid Frame

In this paper, by establishing the finite element model to study the dynamic characteristics of rigid frame single-rib arch bridge. By respectively changing structural parameters of the span ratios, and the compressive stiffness of arch, and the bending stiffness of arch, and the bending stiffness of bridge girder, and the layout of boom to find out the regularity of the structure on lateral stiffness, and vertical stiffness, and torsional stiffness as well as dynamic properties, it come out the results of that lateral stiffness of the structure is weaker, and increasing the span ratios and the compressive strength of arch are conducive to the improvement of the overall stiffness, and improving the bending strength of arch and layout of boom are less effect on the overall stiffness and mode shape.

scholarly journals Influence of the flexibility of beams and slabs in static response and dynamic properties

2016 ◽  
Vol 9 (6) ◽  
pp. 842-855 ◽  
Author(s):  
J. R. BUENO ◽  
◽  
D. D. LORIGGIO ◽  
Keyword(s):  
Finite Element Method ◽  
Natural Frequencies ◽  
Dynamic Properties ◽  
Vibration Modes ◽  
Linear Regime ◽  
Static Response ◽  
The Finite Element Method ◽  
Standard Code ◽  
The Relationship ◽  
Brazilian Standard

Abstract This article examines numerically the flexibility influence of support beams in static response and dynamic properties of a symmetric plate formed by massive slabs of reinforced concrete in elastic linear regime, using the Finite Element Method. In the static response the variation of bending mo-ments and displacements are evaluated, which depend on the relationship between the flexibility of the slab and the beam. The evaluation of dynamic properties is held in undamped free vibration, through which the vibration modes and the values of the natural frequencies is obtained, which are compared with the limits of the Brazilian standard code for design of concrete structures. Results show that the response may show great variation due to the change in the relationship between bending stiffness of the slabs and the beams.

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.

scholarly journals Design and Fabrication of a Wideband Cymbal Transducer for Underwater Sensor Networks

Sensors ◽  
2019 ◽  
Vol 19 (21) ◽  
pp. 4659 ◽  
Author(s):  
Hayeong Shim ◽  
Yongrae Roh
Keyword(s):  
Power Efficiency ◽  
Structural Parameters ◽  
Mechanical Quality Factor ◽  
Voltage Response ◽  
Underwater Sensor Networks ◽  
The Finite Element Method ◽  
Network Systems ◽  
Power Requirement ◽  
Cymbal Transducer ◽  
Mechanical Quality

Cymbal transducers are characterized by a high mechanical quality factor and low power efficiency. The research conducted so far on cymbal transducers has focused on improving the power efficiency and structural stability, but modern underwater sensor network systems need transducers to have a wide frequency bandwidth as well. In this study, a wideband cymbal transducer was designed to fill that need. First, the effect of various structural parameters on the performance of the cymbal transducer was analyzed with emphasis on the bandwidth using the finite element method. Based on the analysis results, the structure of the cymbal transducer was optimized to have the widest possible bandwidth while maintaining its transmitting voltage response (TVR) level over a typical power requirement as well. The validity of the design was verified by fabricating a prototype of the optimized cymbal transducer and comparing its measured performance with the design.

scholarly journals Modelling a Cracked Beam Structure Using the Finite Element Displacement Method

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Hui Long ◽  
Yilun Liu ◽  
Changzheng Huang ◽  
Weihui Wu ◽  
Zhaojun Li
Keyword(s):  
Finite Element ◽  
Dynamic Model ◽  
Structural Parameters ◽  
Element Model ◽  
Beam Element ◽  
The Finite Element Method ◽  
Displacement Method ◽  
Beam Structure ◽  
Cracked Beam ◽  
Local Flexibility

A new model is presented for studying the effects of crack parameters on the dynamics of a cracked beam structure. The model is established by the finite element displacement method. In particular, the stiffness matrix of the cracked beam element is firstly derived by the displacement method, which does not need the flexibility matrix inversion calculation compared with the previous local flexibility approaches based on the force method. Starting with a finite element model of cracked beam element, the equation of strain energy of a cracked beam element is formed by the displacement method combined with the linear fracture mechanics. Then, based on the finite element method, the dynamic model of the cracked beam structure is obtained. The results show that the dynamic model discovers the internal relation between the dynamic characteristics of cracked beam structure and structural parameters, material parameters, and crack parameters. Finally, an example is presented to validate the proposed dynamic model.

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