George Lesieutre • Mary Frecker • Chris Rahn • Zoubeida ... structures.pdf · • Testing,...

ADAPTIVE STRUCTURES AND NOISE CONTROLFaculty Members

• George Lesieutre• Mary Frecker• Chris Rahn• Zoubeida Ounaies• Reginald Hamilton• Kenji Uchino

Dr. Lesieutre projects• Piezoelectric-based Vibration Reduction of

Turbomachinery Bladed Disks via Resonance Frequency Detuning – NASA GRC; student: Jeff Kauffman

• Actuation of Miniature Trailing Edge Effectors for Rotorcraft – NRTC; student: Mike Thiel

• Multistate Fluidic Lag Damper– Lord Corp (w/ Smith); student: Conor Marr

• High-Strength High-Strain Structures Using Ceramic Cellular Contact-Aided Compliant Mechanisms (C3M)– NSF (w/ Frecker, Adair); student: Samantha Cirrone

2

k

short-circuitopen-circuit

Dr. Frecker’s research projects focus on optimal design & fab of compliant mechanisms for medical & aerospace apps

1 mm Compliant Forceps

Collaborators:Dr. J. Adair, MSEDr. C. Muhlstein, MSEDr. R. Haluck, SurgeryDr. A. Mathew, Gastroenterology

Students:Milton AguirreGreg Hayes

Sponsor: NIH NIBIB

Collaborators:Dr. J. Adair, MSEDr. G. Lesieutre, AeroE

Students:Vipul MehtaSamantha CironeGreg Hayes

Sponsor: NSF CMII

Cellular Contact-Aided Compliant Mechanisms

Collaborator:Dr. J. Hubbard, U. Maryland

Student: Yash Tummala

Sponsor: AFOSR

Compliant Spine for Passive Morphing of Ornithopter Wings

• High Performance Piezoelectric Actuators and Wings for Nano Air Vehicles

– AFOSR; Hareesh Kommepalli (PhD 2010), Mark Zhang (MS 2010), Kiron Mateti (PhD 2012), Rory Byrne-Dugan (MS 2012).

• Braille Display Using EAP– NIH; Paul Diglio (MS 2010), Thomas Levard (MS 2011), Michael Robinson (MS 2012).

• EFRI-BSBA: Learning from Plants – Biologically-Inspired Multi-Functional Adaptive Structural Systems

– NSF, Bin Zhu (PhD 2013)• LORD Rotorcraft Center Fellowship

– Lloyd Scarborough (PhD 2012)• Micro Air Vehicle Tether Recovery Apparatus

– AFOSR, Varma Gottimukulla (MS 2011)• Testing, Simulation and Control of Lead-Acid Batteries for Energy

Storage and Regenerative Braking of Hybrid Locomotives– DOE; Ying Shi (PhD 2012), Zheng Shen (PhD 2013), Chris Ferone (MS 2012).

• Development and Experimental Validation of an Electrochemical Control Model of Li-Ion Batteries for Hybrid Electric Vehicles

– Cummins Technical Center, Githin Prasad (PhD 2012).

Dr. Rahn – Mechatronics Research Lab

ADAPTIVE STRUCTURES AND NOISE CONTROLFaculty Members – Featured Research

• George Lesieutre• Mary Frecker• Chris Rahn• Zoubeida Ounaies• Reginald Hamilton• Kenji Uchino

Research in the ElectroactiveMaterials Characterization Laboratory

Zoubeida Ounaies and Group

+

Research Focus

Materials exhibiting electro-mechanical coupling, such as piezoelectric and ferroelectric ceramics, electro-active polymers, and nano-composites for sensing, actuation, electrical energy harvesting, conversion and storage

Health monitoring

Inflatable Antenna

Ultrasonic imaging

Capabilities for synthesis and fabrication

Fabrication

What we do…Develop, synthesize, process, and characterize new adaptive/smart materials

Structure-property relationship for Sensing-

Actuation-Storage

0 V 3 V

Presenter

Presentation Notes

Extensive Expertise in active materials and smart structures Extensive experimental, characterization and modelingof shape memory allows and magnetic shape memory alloys, electroactive polymers and multifunctional nanocomposites: electromechanial, dielectric spectroscopy, thermal and mechancial characterization, synthesis and characterization Modeling: hieracrhical multiscale modeling, discrete to continuum mechanics for scale transitions and thermodynamically-based constitutive modeling for multifunctional materials

ACTIVE NANOCOMPOSITES: ENERGY HARVESTING AND STRESS GENERATION MEDIA FOR FUTURE MULTIFUNCTIONAL AEROSPACE STRUCTURES

Structure-Property Relationship for Sensor-Actuator-Storage

Limitations in Current ElectroactivePolymers (EAPs)

•Inadequate recovery force and work density

•Restricted operation temperatures and frequencies

•Limited development of additional ‘functionality’

•High activation voltages (low dielectric)

EAPFree

strain(%)

E(MV/m)

Polyurethane

Silicone

PVDF-based electrostrictors

PVDF and copolymers

11

100

5

<0.1

150

140

>10

>10

Current Soft Smart Materials: Limitations

Conflicting requirements!

Polymeric Advantages•Form, Shape,

Processing•Large deformation•Multiple Processes

Presenter

Presentation Notes

Nanotechnology is rapidly entering the world of smart materials and taking them to the next level. Nanotechnology and Smart Materials is in depth look at how nanotechnology is enhancing the smart materials area, providing both intrinsic smartness and enhancement of existing smart materials.

• Introduce small amounts of nanoparticles to achieve dramatic changes in Mechanical, Thermal,

Physical, Electrical and / or Chemical Properties

• Establish a tool set for control of nanoparticledistribution: moving to spatially engineered and

designed nano-’composite’ material systems.

Approaches:

Technical Objectives:

• Control morphology of nanoparticles and polymer through processing andelectric field-tailoring to enable optimization of mechanical and electricalcontrast throughout the material, and thus increase “active” response.

• Elucidate critical aspects of the resulting structures to determine limitationsof nanoparticle-based enhancement of performance and enable novelactuation and energy harvesting.

Our Program: Objectives and Approach

Piezoelectric amorphous polymer (β-CN) APB-ODPA—Enhanced Piezoelectricity

Pr= ∆ε.ε0 .Ep

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0.016

0 2 4 6 8 10 12

thickness strain for 0% and 0.1% SWNT in (b-CN)A/O at 10 Hz

out-o

f-pla

ne s

train

(%)

E(MV/m)

0.1%SWNT

0.0%SWNT

d33=6 pm/V

d33=20 pm/V

SWNT-Polyimide Piezoelectric polymer

+

O

CN

N

O

O

N

O

O

O O

n

O

CN

N

O

O

N

O

O

N

O

O

N

O

O

O O

n

Nanocomposites—Enhanced Electrostriction.

0.1% SWNT+ CP2

0.1% SWNT+ polar polyimide

2% SWNT+CP22% SWNT+ polar

polyimide0.26% SWNT+PVDF

Low E

Thickness strain, AC 1Hz

Nanocomposites—Enhanced Electrostriction.

0.1% SWNT+ CP2

0.1% SWNT+ polar polyimide

2% SWNT+CP22% SWNT+ polar

polyimide0.26% SWNT+PVDF

Low E

Thickness strain, AC 1Hz

•Presence of nanoparticles (such as SWNTs) created or enhanced an electrostrictiveresponse. Shown are the electrostrictive coupling coefficients for some of the polymer nanocomposites we developed.

•Achieved higher performance than other existing EAPS, such as PVDF and polyurethane.

Coefficient of Electrostriction

Advantage: Low driving electric fields and high effective dielectric constant

•We have quantified electrostriction performance and associated energy densities.•We have compared the response to state-of-the-art electromechanical actuators.

(PNCs from current study in yellow)

Addition of SWNTs creates a response at low fields with high energy density:

Presenter

Presentation Notes

Advantage position, presence

Processing Approach

Achieved good dispersion of nanoparticles in a variety of thermosetting and thermoplastic polymers:

In Situ PolymerizationUnder Sonication

9 months 1 year

0 min 7 hours

CP-2 (Polyimide)-SWNT, φc = 0.06 vol%

Direct mixing SWNT/Polyimide

In-Situ polymerization+Sonication

Impact on polymer morphology:

Impact on mechanical performance at low vol. % reinforcement better than Halpin-Tsai.

Impact on dielectric behavior at low vol. %

1 year0 min

Demonstrated that nanoparticles improve properties critical for electromechanical coupling:

% CrystallinityPure PVDF 47.284.6 vol% NanoSpheres 52.624.6 vol% NanoWhiskers 51.70

Presenter

Presentation Notes

Notes on acronyms and symbols used: -SWNT refers to Single Wall Nanotubes -NP refers to Nanoparticle -PVDF refers to the piezoelectric polymer Poly(Vinylidene) Fluoride. -PNC refers to Polymer Nanocomposites -(beta-CN) APB/ODPA refers to a polar polyimide. -CP2 refers to a non-polar polyimide. -E or E-field: Electric field. -M refers to the electrostrictive coefficient, which is a fourth-rank tensor. In our case, we measured the in-plane electrostricitve coefficient M1333 and out-of-plane M3333.

How It Works

-SWNTs are extensions of electrodes at high content: high local field increases polarization of mobile regions.

-“Nano-capacitive” network: high effective field for a given potential.

-Joule heating.

E (MV/m)0.0 0.1 0.2 0.3 0.4

Stra

in S

11

0.0000

0.0002

0.0004

0.0006

0.0008

0.0010

0.00120.1vol% SWNT0.5vol% SWNT1vol% SWNT2vol% SWNTPure CP2

Processing Anisotropy Leads to Bending Actuation

DC V

Only bends in one direction

0.5 vol%

0 V 1 V 2 V 3 V

• Functionally graded due to solution-casting

• Processing dependent performance

• Measured strain not material property but

“laminate” –“unimorph” response

Actual

Polymer skin

Presenter

Presentation Notes

M11 and M33 should be comproable.. Experiment: Sample strip dimensions L: 3 cm x W: 0.5 cm x T: ~50 microns Sample electroded with 100 nm Ag on both sides via thermal evaporation One end of strip clamped between two glass slides in vertical manner Electrical contact is supplied via Cu leads running between the slides and the sample V is applied and tip displacement recorded using a high speed camera setup The video is analyzed to determine tip displacement, and subsequently strain Experiments performed within plastic housing to negate environmental effects I take the displacement measured, convert to strain.. (either with 2wt/L2 ) or I take the M33*posion to get M11 and displacement.. Get same strain. Via 4 beam model.. I also get from that model.. A inactive layer of 5 microns.. – get same number Chole sees it bends toward the inactive layer The beam bends toward the resin rich side.. That side is in compression or at zero strain.. Zoubedia see it bend toward the tube rich side.. Since they see expansion in the measuremetns.. Layer with tubes is active layer M11 = S11/E2

Surface Actuation of SWNT-CP2 Films via Resistive Heating

45 mm

45 mm

1 Hz

0.1 Hz

1 vol% SWNT-CP2

Vapp = 280 V AC → Eapp ~ 0.006 MV/mImax = 7.85 mA

Assume catenary shape: y = c cosh(x/c)→ Length of actuated sample (L) = 2(y2 – c2)1/2

Strain (ε) = (L – Lo)/Lo = 1.6%

IR image IR image

Tg (CP2) = 209 oC

σ (film) = 0.012 S/cm (in-plane)

Summary

• We have successfully demonstrated experimentalevidence of the creation of an electrostrictiveresponse in amorphous polymer nanocompositesby addition of small quantities of nanoparticles.

• Most importantly, these improvements wereachieved at much lower actuation voltages, andwere accompanied by increase in bothmechanical and dielectric properties.

• Our efforts reported herein provide new avenuesto significantly improve the electromechanicalresponse of EAP-based nanocomposites.

E (MV/m)0.00 0.05 0.10 0.15 0.20 0.25 0.30

Stra

in S

11

0.0000

0.0002

0.0004

0.0006

0.0008

0.0010

0.0012

0.00140.1vol% SWNT1vol% SWNT2vol% SWNT

E2(MV2/m2)

0.00 0.01 0.02 0.03 0.04 0.05

Stra

in S

11

0.0000

0.0002

0.0004

0.0006

0.0008

0.0010

0.0012

0.00140.1 vol% SWNT1 vol% SWNT2 vol% SWNT

(a)

(b)

Shape Memory Alloys: Material Design

Reginald F. Hamilton, PhDAssistant Professor of Engineering Science and

Mechanics

Spring Workshop of the CAV 2011


The SMA response is due to a solid-solid martensitic phase transformation.

Shape memory effect (SME)

Austenite is the high-temperature phase.

Martensite is the low temperature phase.

ΔTH represents the thermal hysteresis.

Presenter

Presentation Notes

The transformation is diffusionless and results from an underlying atomic crystal structural change. When the material is martensite, it is said to be in its cold shape, when the material is in the beta phase, it is said to be in its hot shape.

Strain, ε

Stress, Σ

Temperature, TSpring Workshop of the CAV 2011

Shape Memory Effect (SME): Deformation mechanism

Heat T > Af/Recover residual ε

CVP Reorientation

Σcr(M)

Austenite

Self-accommodated Martensite (SAM)

CoolT < Ms

Detwinning facilitates preferential Variant A

Inset images copied from Bellouard, Y. (2008) Mat Scie Engr A 481-482, pg 582


Psuedoelastic Effect (PE): Deformation at constant temperature T > Af

stress, Σ

strain, ε

AusteniteReverse MT complete

Σcr(F)

Σcr(R)

A

MartensiteVariant A

Presenter

Presentation Notes

The area under the loading stress-strain curve is the strain-energy per unit volume absorbed by the mat’l Area under unloading curve is the energy released. For this case, the energy which is absorbed is greater than the energy released; and thus, the area within the stress-strain loop is the energy dissipated as heat The hysteresis represents energy which is dissipated in the transformation cycle. The transformation stress levels and the size of the hysteresis vary depending on the SMA material and testingconditions.

The value of the critical stress increases linearly with temperature.


Critical Stress is Temperature Dependent

SME

Presenter

Presentation Notes

Above Ms but below Af, strain induced martensite will remain upon unloading and produce incomplete deformation recovery. SME and PE can be observed in the same specimen.


Non-Ferrous SMA Systems

Otsuka, K. and C. M. Wayman, Eds. (1998). Shape Memory Materials. Cambridge, Cambridge University Press.

Presenter

Presentation Notes

The addition of Cu to NiTi preferentially replaces Ni to form NiTiCu alloys. The unique property of these alloys is that addition of Cu reduces the hysteresis of the SMA response. However, this also results in a decrease in the transformation strain. main Cu-based alloys are found in the Cu-Zn and Cu-Al systems. Although NiTi SMAs offer excellent pseudoelastic and SME properties and are biocompatible, they are relatively expensive compared to Cu-based SMAs. Good electrical and thermal conductivity along with their formability makes Cu-based SMAs an attractive alternative to NiTi. Copper-based alloys generally exhibit less hysteresis than NiTi, with the transformation temperatures in Cu-based alloys highly dependent on the composition. A precise change from 10−3 to 10−4 at.% is sometimes necessary to achieve reproducible transformation temperatures within a 5 ◦C range.


High-Temperature SMA Systems

Firstov, G. S., J. Van Humbeeck, et al. (2004). "Comparison of high temperature shape memory behaviour for ZrCu-based, Ti-Ni-Zr and Ti-Ni-Hf alloys." Scripta Materialia 50(2): 243-248.


Magnetic Field Induced SMA Systems

Pons, J., E. Cesari, et al. (2008). "Ferromagnetic shape memory alloys: Alternatives to Ni-Mn-Ga." Materials Science and Engineering: A 481-482: 57-65.

Presenter

Presentation Notes

For instance, very large magnetic-field-induced strains (up to 10%) can be obtained in properly treated single crystals with good repeatability at elevated frequencies (hundreds of Hz or even kHz). Applications such as rapid magnetic actuators can, then, be envisaged. Other properties of these alloys can also be of interest, like the possibility to have elevated martensitic transformation temperatures with relatively good reproducibility.

Conditions for SME and PE


• SME and PE are realized if the MT is crystallographically reversible and slip does not occur.

• Alloys with ordered atomic structures and also exhibit a thermoelastic MT are favored for SME and PE.

• SME and PE responses depend on chemical composition, cold work, heat treatment, and thermo-mechanical cycling.

Presenter

Presentation Notes

Thermoelastic MTs require are small driving force, which avoids the introduction of dislocations. Mobile twins are present for these MTs and lead to crystallographic reversibility. Crystallographic reversibility and high slip resistance are predominant in ordered structures.


Classes of SMAs: Non-Ferrous SMAsMagnetic Field Induced SMAsHigh-Temperature SMAs

Applications of SMAs


• Free recovery– SMA element causes motion or strain

• Constrained recovery– SMA prevented from changing shape, and thus generates

stress

• Actuator, work production– work is done as motion occurs against a stress

• Energy storage, dissipation– pseudoelastic applications can involve the storage of

potential energy

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