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1 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Course Introduction
DynamicSystems22.451
Peter AvitabileMechanical Engineering DepartmentUniversity of Massachusetts Lowell
jω
σ
UNSTABLESTABLE
TIME
FRF
FRF
TIME
FRF
TIME
FRF
TIME
TIME
TIME
> 1.0ζ
= 1.0ζ
= 0.7ζ
= 0.3ζ
= 0.1ζ = 0ζ
TRANSFER FUNCTION
)S(F)S(H)S(Y •=
LAPLACE DOMAIN
IMPULSE
)t(f)t(h)t(y ⊗=
∫ ττ−τ=t
0d)t(f)(h)t(y
TIME DOMAIN
FRF
)j(F)j(H)j(Y ω•ω=ω
FREQUENCY DOMAIN
RESPONSEMODELS
2 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
What you have learned thus far in other courses
Math & Science RelatedCalculusOrdinary Differential EquationsPhysics
Engineering RelatedStatics & DynamicsStrength of Materials & Applied StrengthMachine Design I & IIMathematical Methods
Why didn’t you tell us ???
3 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Text Book and References
Palm textbook has just been released.Excellent treatment of material for course.
Two other good texts
Vu & Esfandiari Ogata
4 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Overview of this course
5 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Overview of this course
6 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Overview of this course
7 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Overview of this course
Lectures and homework assignments
8 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Overview of this course
Lectures and homework assignments
9 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
http://faculty.uml.edu/pavitabile/22.451/ME22451_PDF_downloads.htm
Course Webpage is your source of information
10 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Peter Avitabile’s Webpage is tag to all course pages
http:// pavitabile.caeds.eng.uml.edu
11 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Why study Dynamic Systems ?
Static systems are rarely observed – but are often used as an approximation for design
Just about everything moves !
Must be able to predict dynamic response of systems for many applications.
Source: Thelen - UWISC
12 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
What are some Dynamic Systems ?
13 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Some systems are of personal interest
Source: Thelen - UWISC
14 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Some systems are inherently fun
Just how much does the bungee stretch ?
ANIMATE
15 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Some systems are technically challenging
response due to shock
ANIMATE
high speed videoshowing drop load
ANIMATE
16 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Some systems need performance enhancements
96.9 3 0.7 0.1 0.3 0.4 0.3 43 0.4 0.3 3.6 2.1 18.2 0.3 14 0.30.2 64.1 1.6 0.1 3.2 3.3 2.7 0.3 2.6 2.7 0.3 2 0.3 1.2 0.5 0.21.8 0.5 3.8 0.7 11.4 1.5 13.2 1.4 12.7 15.7 3.8 2.7 1.6 1.8 1.1 0.40.2 0.6 1.2 96.4 5.1 9.4 0.5 0 0.3 8.7 5.8 0 0 6.9 0 0.10.2 0.8 0.5 0.6 98.3 4.7 48.8 2.2 49.5 24.7 0.9 14.5 0.1 2.4 0.9 0.90.8 4.2 0.7 5.2 22.8 85.5 16.6 0.5 17.5 7.4 12.9 12.5 0.4 5.1 0.8 3.91.9 0.3 0.4 0.5 47.7 2.4 98.4 0.1 57 25.6 11.1 7.1 2 2.7 0.3 1.50.8 0.6 1.4 0.7 50.9 3 59 1.6 97.9 76.9 3.8 9.2 0.4 3.5 0 4.50.2 0.1 2.3 17.2 18.6 0.8 17.8 0.6 66.5 88.4 4.8 5 0.1 16.2 0.3 15.52.3 0.1 0.1 0.3 3.7 0.8 1.1 8.9 2.1 1.1 6.6 8.4 9.8 11.2 15.7 0.5
12.6 2.2 0.8 0.1 1 0.8 0 55.5 0.5 0.4 5.4 23 86.9 2.8 97.4 0.40.3 2 10.1 1 0.2 1.7 4.1 0.2 10.5 17.8 14.6 0.6 0.2 22.7 1 92.8
17 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
Some systems are technically challenging
missile launch responseANIMATE
AIRFRAME
WING
PYLON
MISSILE
TYPICAL CONFIGURATION
18 Dr. Peter AvitabileModal Analysis & Controls Laboratory22.451 Dynamic Systems – Introduction
What needs to be considered to evaluate a system?
Applied Force(speed bump)
Free body Diagram
Dynamic characteristics
Response Specification
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