Department of Mechanical EngineeringUniversity of Houston

A National Science Foundation Sponsored Project

Determination of Damping Ratio of Nanocomposite Plates Using Piezoceramics

Determination of Damping Ratio of Nanocomposite Plates Using Piezoceramics

Christiana ChangHaichang Gu, PhD

Gangbing Song, PhD

Christiana ChangHaichang Gu, PhD

Gangbing Song, PhD

big

pic

ture

Currentcomposites

can be improvedfor many

applications.

Currentcomposites

can be improvedfor many

applications.

b i g

p

i c

t u

r

eVibration affects

passenger comfort and safety.

Vibration affects passenger comfort and

safety.

Project GoalsProject Goalsob

jecti

ve

• Obtain time-domain and frequency-domain responses of nanocompostite plates

• Determine damping ratio of nanocomposite plates

• Analyze results for relationship between weight % of Carbon Nanofiber (CNF) and damping ratio

Figure 1: Carbon Nanofiber (CNF) Paper (Gou, Song, Gu1)

1 Gou, J. and G. Song and H. Gu. “Development of Carbon Nanopaper Based Nanocomposites for Structural Damping Applications.” 2007.backg

rou

nd

Figure 2: Schematic of Vacuum-Assisted Resin Transform Molding Formed

Nanocomposite Composition

Vaccum-Assisted Resin Transform MoldingVaccum-Assisted Resin Transform Molding

backg

rou

nd

- + - + No Voltage

Direction of Polarity

Applied Voltage

opposite polarity Applied Voltage

same as polarity

Direction of Polarity

Direction of Polarity

-+ - +No voltage generated

Directionof Polarity

Voltage generatedsame as polarity

Voltage generatedopposite polarity

Directionof Polarity

Directionof Polarity

F F

Figure 2: Schematic of Lead Zirconate Titanate (PZT) Operation (Olmi, Song, Mo2)

2 Olmi, C and G. Song and Y.L. Mo. “Development of an Innovative Smart Vibration Platform.” The Proceedings of the 4th Japan-China-US

Symposium on Structural Control and Monitoring”, Oct. 16-17, 2006.

PiezoceramicsPiezoceramics

meth

od

s

Sensor

Actuator

Spare Sensor

PreparationPreparation

meth

od

sdSpace Data Acquisition Board

ADC DAC

InputOutput

Power Amplifier

dSpace Enabled PC

Sensor

Actuator

Nanocomposite Plate

ConnectionsConnections

meth

od

sAnalysisAnalysis

ωnω1 ω2

3 dB

meth

od

sAnalysisAnalysis

Half-Band Power AlgorithmHalf-Band Power Algorithm

n

212

resu

lts

Time Domain ResponseTime Domain Response

0.0062

0.0097

0.0146

0.0102

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

-0.25 0.25 0.75 1.25 1.75

Weight % CNF

Da

mp

ing

Ra

tio

resu

lts

Average Damping Ratio vs. Weight % CNFAverage Damping Ratio vs. Weight % CNF

0 0.5 1.0 1.5

con

clu

sio

ns

ConclusionsConclusions• Carbon Nanofibers (CNF) in the

composite matrix significantly damp vibration magnitude

• As weight % of CNF increases, magnitude of response decreases

• As weight % of CNF increases, damping ratio increases

• VARTM molding is capable of producing damped CNF nanocomposite

qu

esti

on

s

g r

a t

I t

u d

e

AcknowledgementsAcknowledgements• National Science Foundation for Funding

of REU

• University of Houston – Host of Program

• Smart Materials and Structures Lab – Host of Project

• Dr. Jan Gou, University of South Alabama – Supplier of Nanocomposite Plates

• REU Participants – For being there!