Texas A&ME3 Summer Research

Program Class Project

Jeffrey DerryJune 27, 2007

Topics…The questionGeneral TEA objectivesSpecific lesson objectivesThe experimentThe test rigGraphs of the dataConclusionsExtensionsAcknowledgements

THE QUESTION

Which of the given test materials provides the greatest damping on the

harmonic motion of a given base material?

General Objectives: To identify the characteristics of a

graph of a real world application To use graphical analysis to justify a

decision

Specific Objectives:To collect data using the TI-CBRTo import data into ExcelTo identify relative maximaTo identify the period and frequency of a

graph of harmonic motionTo use Excel to graph and interpret dataTo determine which of the test materials

has the greatest damping effect

Experiment:Each group of students will…1.Set up the test rig according to specification,

given the spec sheet and materials.2. For the base and 3 damping materials runs

A. Use the CBR to collect data (time, distance)B. Use TI-Connect to export the data to ExcelC. Make a stat plot for the dataD. Identify the relative maxima for the test runE.Determine the period and frequency for the test run

3. Present a data and graphical analysis of all graphs to determine which material has the greatest damping effect on the base material.

Group ResponsibilitiesPerform experiment

Collect data

Import data into Excel

Interpret data

Plan presentation

Group-1

Group-2

Groups 1&2

NOTE: It is suggested that groups 1 and 2 switch responsibilities after test run 2.

The Test Rig

TEST RIG Fig-01

TEST RIG Fig-02

TEST RIG Fig-03

CBR

TI-83

TEST RIG Fig-04

30 cm

CBR

TI-83

30 cm

10 cm

TEST RIG Fig-05

TEST RIG Fig-06

BASE TEST RIG Fig-07

RUBBER FOAM TEST RIG Fig-08

Damping material

Damping Materials

Felt

Vinyl

Rubber

Graphs of the Data

Metal Base

0.63

0.64

0.65

0.66

0.67

0.68

0.69

0 0.5 1 1.5 2 2.5 3

Distance m

Time sec

Felt

0.645

0.65

0.655

0.66

0.665

0.67

0.675

0.68

0.685

0.69

0 0.5 1 1.5 2 2.5 3

Distance m

Time sec

Vinyl Foam

0.62

0.63

0.64

0.65

0.66

0.67

0.68

0.69

0.7

0.71

0 0.5 1 1.5 2 2.5 3

Distance m

Time sec

Rubber Foam

0.62

0.63

0.64

0.65

0.66

0.67

0.68

0.69

0.7

0 0.5 1 1.5 2 2.5 3

Distance m

Time sec

Response Comparison

0.62

0.63

0.64

0.65

0.66

0.67

0.68

0.69

0.7

0.71

0 0.5 1 1.5 2 2.5 3

time (sec)

base felt vinyl foam rubber foam

Dis

tanc

e (m

)

Time (sec)

Base Felt Vinyl Rubber

Response Comparison

ConclusionsUsing the data for each test run…The approximate period for each is 0.096768 secThe approximate frequency is 1/0.096768

or 10.33399 cycles/sec

The felt material exhibited the greatest damping effect on the base material.

ExtensionsDiscuss the theoretical approach to predicting harmonic motionUse the TI-83 to regress the maxima data

of set to identify damping factor, Discuss the use of damping materials in

real world applications

AcknowledgementsDr. Andrew Conkey

Consultant, Fabricator

Dr. Daejong KimMentor