THUNDER Actuator

1
THUNDER Actuator
Gevale R. Ashford
Finite Element Modeling of Thin-layer composite
unimorph ferroelectric driver and sensor
(THUNDER) actuators.

• Acknowledgments
• Kenneth Ulibarri
• Adalia Cabanyog
• Alec Sim
• Chris Kennedy
• Tim Usher
• Funding Provided by
• California State University, San Bernardino
• National Aeronautic Space Administration
• Grant 0051-0078

2
How are they manufactured?

• THUNDER actuators are manufactured by binding a
  thin sheet of piezoelectric ceramic under
  hydrostatic pressure between a metal substrate
  and an aluminum electrode at a 320 C.
• During the cooling process a difference in the
  coefficients of thermal expansion between the
  layers cause the actuator to deform to a shallow
  dome shape.
• The fabrication of THUNDER actuators is completed
  by the perpendicular poling of the ceramic to the
  metal interface.

3
How does it work?

• When a voltage is applied to the actuator the
  ceramic layer tends to contract resulting in a
  flatter actuator.
• When the voltage is released the actuator tends
  to return to its natural dome shape.
• If any type of mass or load were placed on top of
  the actuator and a voltage was applied and
  released the actuator would act as a spring
  ultimately moving the load or mass.
• Varying the applied voltage can alter the force
  that is created when the actuator returns from
  its displaced position.

4
Where did the idea originate?

• RAINBOW (Reduced and Internally Biased Oxide
  Wafer)
• Displacement for RAINBOW actuators showed to be
  10-25 lower than THUNDER actuators.
• THUNDER actuators are very rugged in comparison.
• In addition standard commercial manufacturing
  techniques have been developed for THUNDER
  actuators.
• To date there has been no such manufacturing
  techniques developed for RAINBOW actuators.

5
Potential Applications

• Engineers in the Aerospace industry will greatly
  benefit from the added technology that THUNDER
  actuators have to offer.
• These actuators could potentially change the
  surface of aircraft wings while in flight.
  Improving on maneuvers such as takeoffs and
  landings.
• For NASA scientist further development of THUNDER
  actuators may lead to improvements on the quality
  and reliability of the data that their space
  exploration robots collect.
• A computer could apply a voltage to the actuators
  located on the wheels of a moon rover and insure
  that its readings were not interrupted by any
  vibrations caused by debris on the planets
  surface.

6
Finite Element Modeling Theory

• FEM consists of a computer model of a material or
  design that is loaded and analyzed for specific
  results.
• Mathematically, the structure to be analyzed is
  subdivided into a mesh of finite sized elements
  of simple shape.
• Within each element the variation of displacement
  is determined by simple polynomial shape
  functions and nodal displacement.
• From this, the equations of equilibrium are
  assembled in a matrix form that can be easily
  programmed and solved by a computer.

7
Research Goals

• To develop better mathematical and computer
  models for HDAs.
• To fabricate new and better actuators-via design
  templates as opposed to the crude trial and error
  method.
• To improve the performance of THUNDER actuators
  by improving their manufacturing process.
• We will also assist NASA research team in
  producing more effective actuators with our data.

8
Experimental Procedures

• Utilizing the ANSYS modeling software, several
  computer models have been constructed.
• These models have been constructed using input
  variables directly from the command line as well
  as from the toolbars via the GUI interface.
• The dimensions as well as the material properties
  of each element being used in the construction of
  each model have been defined in order to emulate
  its physical counterpart.

9
Experimental Procedures, Cont.

• It will be our focus to compare the data obtained
  from the models and laboratory experiments to
  data recorded in previously related experiments.
• These comparisons will insure two things
• 1. Our experiments are on track and relevant to
  previously found data.
• 2. Keep the focus of our experiments at exceeding
  and improving on related NASA experimental
  findings.

10
Results

• Researchers have been diligently working on the
  NASA project through out the summer and now
  continuing during the fall quarter.
• After spending numerous hours in the laboratory
  working with the ANSYS software researchers have
  gained substantial knowledge and experience in
  constructing computer generated models.
• We still have a notable amount of experience and
  knowledge to gain before we are to be considered
  leading experts in the field of computer
  modeling.
• Recently we have began construction of a computer
  modeled static mode actuator.

11
Results, Cont.

• We have defined the dimensions to exactly
  represent THUNDER model TH 8-R in every aspect.
• Currently we are testing the actuator under a
  range of applied voltages to measure its
  displacement.
• The next goal on the agenda for our research team
  will be to compare the data that is currently
  being recorded from our ANSYS models to the data
  being recorded from our laboratory experiments.
• The comparisons of these results will give our
  research team a better understanding of these
  THUNDER actuators maximum potential.

12
Layer composition of THUNDER actuator before
bonding occurs.

• The top layer (purple) is the aluminum electrode.
• The middle layer (teal) is the piezoelectric
  ceramic.
• The bottom layer (purple) is the metal (stainless
  steel) substrate.

13
Layer composition of THUNDER actuator after
bonding has occurred.
14
(No Transcript)
15
(No Transcript)
16
(No Transcript)
17
(No Transcript)
18
(No Transcript)
19
(No Transcript)
20
Technology used in research

• ANSYS 6.0
• Finite Element Modeling Program
• Hummingbird Exceed 7.1.1
• X Windows Emulator Program
• Solaris 5.8
• Unix Operating System
• Red Hat Linux 7.2, Windows XP OS

21
Related Documents

• A Feasibility Study To Control Airfoil Shape
  Using THUNDER Actuators
• Jennifer L. Pinkerton and Robert W. Moses
• National Aeronautic and Space Administration
• Langley Research Center, Hampton, Virginia
• November 1997
• Load Characterization of High Displacement
  Piezoelectric Actuators with Various End
  Conditions
• James Mulling, Tim Usher, Brian Dessent, Jeremy
  Palmer, Paul Franzon, Eddie Grant and Angus
  Kingon
• Materials Research Center, North Carolina State
  University
• May 2000

22
Related Documents, Cont.

• Validation of High Displacement Piezoelectric
  Actuator Finite Element Models
• Barmac K. Taleghani
• U.S. Army Research Laboratory
• Vehicle Technology Directorate
• Langley Research Center, Hampton, Virginia
• August 2000
• Modeling and Simulation of THUNDER Actuators
  Using ANSYS Finite Element Analysis
• Chris Kennedy, Tim Usher, James Mulling and Angus
  Kingon
• Fourth International Conference on Modeling and
  Simulation of Microsystems, Head Island, South
  Carolina
• March 2001