Displacement and Blocking Force Performance of Piezoelectric T-Beam Actuators

2010 ◽  
Author(s):  
Hareesh K. R. Kommepalli ◽  
Kiron Mateti ◽  
Christopher D. Rahn ◽  
Srinivas A. Tadigadapa
Keyword(s):  
Theoretical Prediction ◽  
Cross Section ◽  
Experimental Validation ◽  
Analytical Models ◽  
Out Of Plane ◽  
Cantilevered Beam ◽  
Beam Displacement ◽  
T Beam ◽  
Meso Scale ◽  
Shaped Cross Section

In this paper, we present the experimental validation of the detailed models developed for the flexural motion of piezoelectric T-beam actuators. With a T-shaped cross-section, and bottom and top flange and web electrodes, a cantilevered beam can bend in both in-plane and out-of-plane directions upon actuation. Analytical models predict the tip displacement and blocking force in both directions. Mechanical dicing and flange electrode deposition was used to fabricate six meso-scale T-beam prototypes. The T-beams were experimentally tested for in-plane and out-of-plane displacements, and out-of-plane blocking force. The analytical models closely predict the T-beam displacement and blocking force performance. A nondimensional analytical model predict that all T-beam designs for both in-plane and out-of-plane actuation, regardless of scale, have nondimensional displacement and blocking force equal to nondimensional voltage. The results from experiments are favorably compared with this theoretical prediction.

Piezoelectric T-Beam Actuators

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Hareesh K. R. Kommepalli ◽  
Kiron Mateti ◽  
Christopher D. Rahn ◽  
Srinivas A. Tadigadapa
Keyword(s):  
Cross Section ◽  
Performance Optimization ◽  
Mechanical Energy ◽  
Analytical Models ◽  
Width Ratio ◽  
Maximum Displacement ◽  
Out Of Plane ◽  
Cantilevered Beam ◽  
Beam Displacement ◽  
T Beam

This paper develops models, fabricates, experimentally tests, and optimizes a novel piezoelectric T-beam actuator. With a T-shaped cross-section, and bottom and top flanges and web electrodes, a cantilevered beam can bend in both in-plane and out-of-plane directions upon actuation. Analytical models predict the tip displacement and blocking force in both directions. Six mesoscale T-beam prototypes are monolithically fabricated by machining and microfabrication techniques and experimentally tested for in-plane and out-of-plane displacements and out-of-plane blocking force. The analytical models closely predict the T-beam displacement and blocking force performance. A nondimensional analytical model predicts that all T-beam designs for both in-plane and out-of-plane actuations, regardless of scale, have nondimensional displacement and blocking force equal to nondimensional voltage. Another form of nondimensional model optimizes the T-beam cross-section for maximum performance. Optimization study shows that a cross-section with width ratio, b*, and thickness ratio, t*, approaching zero produces maximum displacement, b*=t*=0.381 produces maximum blocking force, and b*≈0.25, t*≈0.33 produces maximum mechanical energy.

Piezoelectric T-Beam Microactuators

2008 ◽  
Author(s):  
Hareesh K. R. Kommepalli ◽  
Andrew D. Hirsh ◽  
Christopher D. Rahn ◽  
Srinivas A. Tadigadapa
Keyword(s):  
Cross Section ◽  
Fabrication Process ◽  
Mems Fabrication ◽  
Out Of Plane ◽  
Cantilevered Beam ◽  
Piezoelectric Mems ◽  
The Cross ◽  
T Beam ◽  
Cross Section Geometry

This paper introduces a novel T-beam actuator fabricated by a piezoelectric MEMS fabrication process. ICP-RIE etching from the front and back of a bulk PZT chip is used to produce stair stepped structures through the thickness with complex inplane shapes. Masked electrode deposition creates active and passive regions in the PZT structure. With a T-shaped crosssection, and bottom and top flange and web electrodes, a cantilevered beam can bend in-plane and out-of-plane with bimorph actuation in both directions. One of these T-beam actuators is fabricated and experimentally tested. An experimentally validated model predicts that the cross-section geometry can be optimized to produce higher displacement and blocking force.

Vibrations in a spatial K-shaped metallic frame: an exact analytical study with experimental validation

2016 ◽  
Vol 23 (19) ◽  
pp. 3147-3161
Author(s):  
C Mei
Keyword(s):  
Cross Section ◽  
Experimental Validation ◽  
Analytical Study ◽  
Torsional Rigidity ◽  
Space Frame ◽  
Bending Vibrations ◽  
Beam Elements ◽  
Out Of Plane ◽  
Vibration Responses ◽  
Shear Distortion

In a spatial K-shaped metallic frame, there exist in- and out-of-plane bending, axial, and torsional vibrations. A wave-based vibration analysis approach is applied to obtain free and forced vibration responses in a space frame. In order to validate the analytical approach, a steel K-shaped space frame was built by welding four beam elements of rectangular and square cross-section together. Bending vibrations are modeled using both the classical Euler–Bernoulli theory and the advanced Timoshenko theory. This allows the effects of rotary inertia and shear distortion, which were neglected in the classical Euler–Bernoulli theory, to be studied. In addition, the effect of torsional rigidity adjustment for structures of rotationally non-symmetric cross-section is also examined.

Uniform Horizontal Groundwater Flow against Dispersion in a Shallow Aquifer: Two Analytical Models

1992 ◽  
Vol 23 (1) ◽  
pp. 1-12
Author(s):  
Ram Raj Vinda ◽  
Raja Ram Yadava ◽  
Naveen Kumar
Keyword(s):  
Point Source ◽  
Groundwater Flow ◽  
Cross Section ◽  
Analytical Solutions ◽  
Concentration Distribution ◽  
Analytical Models ◽  
Shallow Aquifer ◽  
Horizontal Cross Section ◽  
Flow Components ◽  
Reactive Pollutant

Analytical solutions converging rapidly at large and small values of times have been obtained for two mathematical models which describe the concentration distribution of a non reactive pollutant from a point source against the flow in a horizontal cross-section of a finite saturated shallow aquifer possessing uniform horizontal groundwater flow. Zero concentration or the conditions in which the flux across the extreme boundaries are proportional to the respective flow components are applied. The effects of flow and dispersion on concentration distribution are also discussed.

scholarly journals Influence of technical parameters on the structure of annular axis braided preforms

2021 ◽  
Vol 28 (1) ◽  
pp. 160-168
Author(s):  
Xi Wang ◽  
Guoli Zhang ◽  
Xiaoping Shi ◽  
Ce Zhang
Keyword(s):  
Cross Section ◽  
Rotation Speed ◽  
Technical Parameters ◽  
Braiding Angle ◽  
Shaped Cross Section

Abstract A modified vertical braiding machine and closed annular axis mandrels with a special-shaped cross section were used to braid annular axis preforms under four different technical parameters. After measuring the braiding angles and yarn spacing of the braided preform in different areas of the mandrels, it was found that the braiding angle increased by 20.9% and the yarn spacing decreased by 19.8% when the speed of the yarn carrier was doubled. The braiding angle decreased by 31.1% and the yarn spacing increased by 28.6% when the rotation speed of the mandrels was doubled. The results show that the rotation speed of the mandrel has a slightly greater influence on the braiding angle and the yarn spacing. By using the modified braiding machine to braid the annular axis preforms, multi-layer continuous braided preforms can be achieved on compact equipment. And the structure of the annular axis braided preforms can be changed by changing the technical parameters.

Comparison of Analytical and Empirical Models to Capture Variations in Off-Road Vehicle Dynamics

2005 ◽  
Author(s):  
Paul J. Pearson ◽  
David M. Bevly
Keyword(s):  
Empirical Data ◽  
Vehicle Dynamics ◽  
Experimental Validation ◽  
Inertial Sensors ◽  
Analytical Models ◽  
Control Algorithms ◽  
Model Parameters ◽  
Steering Control ◽  
Steering Angle ◽  
Yaw Rate

This paper develops two analytical models that describe the yaw dynamics of a farm tractor and can be used to design or improve steering control algorithms for the tractor. These models are verified against empirical data. The particular dynamics described are the motions from steering angle to yaw rate. A John Deere 8420 tractor, outfitted with inertial sensors and controlled through a PC-104 form factor computer, was used for experimental validation. Conditions including different implements at varying depths, as would normally be found on a farm, were tested. This paper presents the development of the analytical models, validates them against empirical data, and gives trends on how the model parameters change for different configurations.

Coupled Pitch Links for Multiharmonic Isolation Using Fluidic Circuits

2014 ◽  
Vol 59 (4) ◽  
pp. 1-11
Author(s):  
Lloyd H. Scarborough III ◽  
Christopher D. Rahn ◽  
Edward C. Smith ◽  
Kevin L. Koudela
Keyword(s):  
Experimental Validation ◽  
Analytical Models ◽  
Main Rotor ◽  
Fluidic Devices ◽  
Simulation Results ◽  
Fluidic Circuits ◽  
Blade Loads

Replacing stiff pitch links on rotorcraft with coupled fluidic devices has the potential to reduce the aerodynamic blade loads transmitted through the pitch links to the swashplate. Analytical models of two fluidic devices coupled with three different fluidic circuits are derived. These passive fluidlastic systems are tuned, by varying the fluid inertances and capacitances of each fluidic circuit, to reduce the transmitted pitch-link loads. The different circuit designs result in transmitted pitch-link loads reduction at up to three main rotor harmonics. The simulation results show loads reduction at the targeted out-of-phase and in-phase harmonics of up to 88% and 93%, respectively. Experimental validation of two of the fluidic circuits demonstrates loads reduction of up to 89% at the out-of-phase isolation frequencies and up to 81% at the in-phase isolation frequencies.

Stress concentration factors for the torsion of curved beams of arbitrary cross-section

2006 ◽  
Vol 220 (12) ◽  
pp. 1709-1726 ◽  
Author(s):  
R E Cornwell
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Cross Section ◽  
Cross Sections ◽  
Shear Stresses ◽  
Curved Beams ◽  
Finite Element Implementation ◽  
Out Of Plane ◽  
Concentration Factors ◽  
Stress Concentration Factors

There are numerous situations in machine component design in which curved beams with cross-sections of arbitrary geometry are loaded in the plane of curvature, i.e. in flexure. However, there is little guidance in the technical literature concerning how the shear stresses resulting from out-of-plane loading of these same components are effected by the component's curvature. The current literature on out-of-plane loading of curved members relates almost exclusively to the circular and rectangular cross-sections used in springs. This article extends the range of applicability of stress concentration factors for curved beams with circular and rectangular cross-sections and greatly expands the types of cross-sections for which stress concentration factors are available. Wahl's stress concentration factor for circular cross-sections, usually assumed only valid for spring indices above 3.0, is shown to be applicable for spring indices as low as 1.2. The theory applicable to the torsion of curved beams and its finite-element implementation are outlined. Results developed using the finite-element implementation agree with previously available data for circular and rectangular cross-sections while providing stress concentration factors for a wider variety of cross-section geometries and spring indices.

scholarly journals Design of an Edge Slotted Waveguide Antenna Array Based on T-Shaped Cross-Section Waveguide

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Teng Li ◽  
Wenbin Dou
Keyword(s):  
Surface Wave ◽  
Antenna Array ◽  
Cross Section ◽  
Mutual Coupling ◽  
Dominant Mode ◽  
Waveguide Structure ◽  
Center Frequency ◽  
Sidelobe Level ◽  
Slotted Waveguide ◽  
Shaped Cross Section

An edge slotted waveguide antenna array based on T-shaped cross-section radiating waveguide is proposed. The T-shaped waveguide is analyzed and designed to operate in dominant mode around the center frequency, which has a lower profile compared with the rectangular one. The radiating slots are etched and rotated alternatively on the broadened top plate without cutting into the adjacent walls. The metal fences are inserted between slots to reduce the mutual coupling and surface wave. Therefore, the sidelobe level in E-plane is well suppressed. A 2 × 8 antenna array working at Ka-band is designed and fabricated. The measured results agree well with simulations which demonstrate this novel waveguide structure.

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