View
219
Download
1
Category
Preview:
Citation preview
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 1/25
1
ME240/105S: Product Dissection
From Ref. 5, used by permission ofRodale Press, ©1994, all rights reserved
Bicycle Design andConstruction
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 2/25
2
ME240/105S: Product Dissection
Diferent Frame
Construction Philosophies
Cannondale !elded aluminum frames, hand "rafted
#pe"iali$ed !elded steel or "hromemoly %a steel alloy&
're( glued aluminum frames, or !elded steel
)i"y"le "ompanies tend to have different designphilosophies, to give them a uni*ue mar(et +ni"he-
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 3/25
3
ME240/105S: Product Dissection
FrameComponen
tsfrom Ref. , used !ith permission of /orling 0indersley, ©199, all rights reserved
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 4/25
4
ME240/105S: Product Dissection
Joining Processes or Frame
Tubing
from Ref. , used !ith permission of /orling 0indersley, ©199, all rights reserved
4
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 5/25
5
ME240/105S: Product Dissection
Cannondale Factory Tour -
CAD 2ll of Cannondale3s bi"y"le frames are
designed on highte"h C2/ systemsin the R/ department at the )ethel,Conne"ti"ut head*uarters.
e! frame designs are then sent viamodem to the Cannondale fa"tory in
)edford, Pennsylvania.
'he follo!ing are e6"erpts from http-77!!!."annondale."om7fa"toryb7f.html
5
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 6/25
6
ME240/105S: Product Dissection
Cannondale Factory Tour - Ra
Tubing 8ith the e6"eption of "arbon
fiber7aluminum Raven models, allCannondale bi"y"les are built fromlight!eight ::: series aluminumtubes !ith different diameters, shapes,and !all thi"(nesses.
::: series aluminum is used be"auseit "an be shaped and ma"hined mu"heasier than ;::: series aluminum ormetal matri6 aluminum "ompounds.
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 7/25
7
ME240/105S: Product Dissection
Cannondale Factory Tour - !aser
Cutting Computer guided lasers are used to
pre"isely "ut aluminum frame tubes tothe proper length.
#ele"ted tubes are also mitered to!rap around ad<oining tubes.
'he lasers provide a "leaner "ut thantraditional "utting methods and ensurein"redibly tight toleran"es for greater!eld integrity and a stronger frame.
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 8/25
8
ME240/105S: Product Dissection
Cannondale Factory Tour - Tabs "
#lots 'he tubes on Cannondale frames
feature a uni*ue, patented taband"orrespondingslot design that aligns
the tubes for !elding. )y eliminating the need to build
numerous produ"tion fi6tures for ea"hsi$e and every ne! frame style, thistabandslot system dramati"allyredu"es preprodu"tion engineering"hores and allo!s Cannondale to bringinnovative ne! models to mar(et !ithama$ing speed.
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 9/25
9
ME240/105S: Product Dissection
Cannondale Factory Tour - T$%
&elding 'he ::: series aluminum frames are
then '=> !elded together by hand.
8elding the thin!alled ::: seriesaluminum tubing used in "uttingedgebi"y"le frames is a surprisingly diffi"ultart to master.
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 10/25
10
ME240/105S: Product Dissection
Cannondale Factory Tour - 'eat
Treating Cannondale then heattreats their
frames to restore the tubes to theiroriginal strength after !elding.
2 frustratingly diffi"ult %and e6pensive&pro"ess to perfe"t, heattreating allo!sCannondale to a"tually use lessmaterial to a"hieve the ne"essarylevels of strength.
?any other manufa"turers use thi"(er!alled tubing or reinfor"ing gussets,both of !hi"h add !eight.
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 11/25
11
ME240/105S: Product Dissection
Cannondale Factory Tour -
#anding )eyond the obvious aestheti" benefit,
smooth, sanded !elds help preventstressrisers !hi"h "an o""ur at the
outer edge of an unfinished !eld,!here the !eld abruptly ends and thetube !all is suddenly thinner and moreprone to a""umulated stresses.
'he gradually tapering !alls "reated by properlyfinished !elds, ho!ever, disperse stresses over a!ider area, allo!ing Cannondale to use thinner
!alled tubes for a lighter frame.
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 12/25
12
ME240/105S: Product Dissection
Cannondale Factory Tour -
For the most even, most "onsistent"overage possible, Cannondale paintstheir frames ele"trostati"ally !hereby
the frame "arries a small ele"troni""harge that a"tually attra"ts individualpaint parti"les.
2fter painting, ea"h frame has itsde"als applied and is "lear"oated !itha durable, prote"tive finish.
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 13/25
13
ME240/105S: Product Dissection
Cannondale Factory Tour -
Testing Cannondale has invested over a
million dollars in their @Aab, an inhouse testing fa"ility for bi"y"le
frames and "omponents. 2 ne! frame design typi"ally spends
more than t!o months undergoingfive different batteries of tests-
1. fatigue testing,. impa"t testing,. finite element analysis testing,4. "omputeri$ed field testing, and
5. brittle"oat testing.
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 14/25
14
ME240/105S: Product Dissection
!oo( at one #imple
#ubsystem - Frame Tubing Frame design is an e6"ellent e6ample of the tradeoffs inherent in
the design pro"ess and the sometimes arbitrary de"isions %i.e., not <ustifiable based on purely analyti"al terms& !hi"h are often made
'here are lots of possibilities %variables& for frame design- B material %steel, aluminum, titanium, "omposite, ...&
B "ross se"tion shape
shape %s*uare, round, oval or other&
hollo! or solid
"onstant "ross se"tion, or variable
Do! do you handle all this information and ma(e a proper"hoi"e E
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 15/25
15
ME240/105S: Product Dissection
Design Process
1. 'he first step in design ASK QUESTIONS
B intended use of produ"t
B desired or important performan"e *ualities
for bi(e lo! !eight, riding effi"ien"y, "omfort, durability,lo! "ost ...
B potential failure modes
B ho! does the part fit into overall system
. =dentify design variables %things you as thedesigner "an spe"ify&
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 16/25
16
ME240/105S: Product Dissection
Design Process -
continued . @uantify the performan"e *ualities in terms of
the design variables
4. =dentify the "onstraints based on potential failuremodes and performan"e *ualities
5. Formulate a measure of the design3s +goodness%*uantitative if possible&
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 17/25
17
ME240/105S: Product Dissection
. 2pply an appropriate design method for "hoosing thea"tual values of the design variables-
B 'rial and error %0 for simple problems& B Past e6perien"e %e6trapolation or interpolation&
B =ntuition, dumb lu"(
B umeri"al optimi$ation methods %a ne"essity if the number of designvariables and "onstraints are large&
Design Process -
continued
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 18/25
18
ME240/105S: Product Dissection
Bac( to the Frame Tube
Aet3s assume that the most important *ualities ofthis tube are its- B Ao! Fle6ibility %G high stiffness&
B Ao! 8eight %!ant as light as possible&
B Digh )ending and Crush #trength
B Aong Aife
/esign Hariables- B ?aterial
B 8all thi"(ness
B 'ube /
B Ioining method %!eld, glue, bra$e&
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 19/25
19
ME240/105S: Product Dissection
Bi(e Tubing
)etter tubes arethi"(er at ends togive greaterstrength at <oints
plain gage tube
single-butted tube
double-butted tube
triple-butted tube
From Ref. 5, used by permission of Rodale Press, ©1994, all rights reserved
ME240/105SP d D
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 20/25
20
ME240/105S: Product Dissection
)aterial Design $ssues
8hy does Cannondale use aluminumE
8hat are its advantages and disadvantagesE
ther possibilities- B #teels
Ao! Carbon, Digh Carbon, Chromemolybdenum,#tainless ...
B 'itanium B ?agnesium
B Carbon fiber "omposite %Carbon Fiber, 0evlar&
ME240/105SP d tDi ti
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 21/25
21
ME240/105S: Product Dissection
$mportant )aterial
Properties 8eight %density&
#tiffness %elasti" modulus&
#trength %tensile strength, enduran"e limit&
=mpa"t resistan"e %hardness&
Corrosion resistan"e
Ioining methods
Re"y"ling potential
ME240/105SP d tDi ti
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 22/25
22
ME240/105S: Product Dissection
Comparison o )aterial
Properties
Elastic Yield TensileMaterial Modulus Strength Strength
[Mpsi] [Kpsi] [Kpsi] [lb/in] !ardness
2luminum :1 ' 1: 4: 45 .1: 95 J1J.5: ;:;5 ' 1: ; K .1: 15: JJ.:#teel 1:4: DR %med "arbon& : 4 ; .K 149 J:.5J1 1:4: C/ : ;1 K5 .K 1;: + 414: DR %"hrome7moly& : 9: .K 1K; +
414: C/ : 9: 1: .K +'itanium 4 1.5 1:15: 1:1: .1 72 J1J9:
>raphite7Lpo6yM 1: 15: ::: .: 72 J5J;
DR G Dot Rolled C/GCold /ra!nM 2"tual properties depend on the type and amount of reinfor"ing material
ME240/105SP d tDi ti
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 23/25
23
ME240/105S: Product Dissection
#tatic #trength
Results from a typi"al tensiletest of a steel sample
from ?anufa"turing Lngineering and 'e"hnology, by #. 0alpaa(<ian,used by permission of 2ddison 8esley, ©199, all rights reserved
ME240/105SProdctDissection
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 24/25
24
ME240/105S: Product Dissection
Fatigue *Cyclic+ #trength
Fatigue properties are verydependent on material type.
#teels have an enduran"e
limit a stress level !hi"h "anbe endured for an unlimitednumber of "y"les %no fatigue&.
2luminum does not have an
enduran"e limit and fatiguesno matter !hat the stresslevel. 'herefore, an aluminumbi(e must be built !ith e6trastrength to a""ount for fatigueeffe"ts.
1045 Steel
Endurance Limit
2014-T6
Aluminum alloy
Number of Cycles, N
S
t r e s s A m p l i t u d e ,
S ( M P a )
K p s i
80
500
0
103 1010
0
ME240/105S:ProductDissection
7/23/2019 Bicycle Design and Construction
http://slidepdf.com/reader/full/bicycle-design-and-construction 25/25
25
ME240/105S: Product Dissection
Cannondale TubeCannondale uses aluminum tubing, 1.;5 /, .:K5 "onstant !all
thi"(ness a good "ompromise bet!een !eight and fle6ibility
WALL THICKNESS - inches
0 0.05 0.1 0.15 0.2 0.25
WEIGHT
FLEXIBILITY
OD - 1.75”
Recommended