DESIGN OF UNMANNED AERIAL COMBAT VEHICLE

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Aircraft Design Project 2 -DESIGN OF UNMANNED AERIAL COMBAT VEHICLE

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Design Of Unmanned Combat Aerial Vehicle
DESIGN OF UNMANNED COMBA AE!IA" VE#IC"E
A $!O%EC !E$O!
Submitted by
C#!ISO$#E! B#A!A#&M
D#INES# 'UMA!&U
in partial fulfillment for the award of the degree
of
BAC#E"O! OF ENGINEE!ING
in
AE!ONAUICA" ENGINEE!ING
Page 1
Design Of Unmanned Combat Aerial Vehicle
!A%A"A'S#MI ENGINEE!ING
CO""EGE(#ANDA"AM)*+,-+.
ANNA UNIVE!SI/00
C#ENNAI *++ +,.
NOVEMBE! ,+-,
!A%A"A'S#MI ENGINEE!ING
CO""EGE
#ANDA"AM 1 *+, -+.
BONAFIDE CE!IFICAE
This is to certify that this is a bonafide record of work done by the student ,
,III year Aeronautical Engineering in the AIRCRAFT DESIG !R"#ECT $% &aboratory
during the acade'ic year ()%%$()%(.
Page 2
UNIVERSITY REGISTER No.
211091010
Design Of Unmanned Combat Aerial Vehicle
Signat2re of Fac2lt3)in)Charge
S2bmitted for the $ractical E4amination held on 5555555555&&
Internal E4aminer E4ternal E4aminer
AC'NO6"EDGEMEN
*e would like to e+tend our heartfelt thanks to $rof& /ogesh '2mar Sinha for
gi,ing us his able su--ort and encourage'ent. At this /uncture we 'ust e'-hasis
the -oint that this design -ro/ect would not ha,e been -ossible without the highly
infor'ati,e and ,aluable guidance of Mr& S2rendra Bogadi 0Asst. !rofessor of
Aeronautical De-art'ent1, whose ,ast knowledge and e+-erience has greatly
hel-ed us in this -ro/ect. *e ha,e great -leasure in e+-ressing our sincere and
whole hearted gratitude to the'.
It is worth 'entioning about 'y friends and colleagues of the Aeronautical
de-art'ent for e+tending their kind hel- whene,er the necessity arose. I thank one
and all who ha,e directly or indirectly hel-ed us in 'aking this design.
Page 3
Design Of Unmanned Combat Aerial Vehicle
INDE7
Page 4
Serial no& Content $age no
%. Introduction
(. Data Fro' AD!$I
2. Ai' 3 "b/ecti,e
4. Three 5iew Diagra'
6. 5$n Diagra'
7. Gust En,elo-e
8. Schrenk9s Cur,e
:. &oad Esti'ation "n *ing
;. <aterial Selection
%).
Detailed *ing Design
0S-ar Design1
%%. Conclusion
%(. =ibliogra-hies and references
Design Of Unmanned Combat Aerial Vehicle
S/MBO"S AND NOAIONS USED
A.R. $ As-ect Ratio
= $ *ing S-an 0'1
C $ Chord of the Airfoil 0'1
C $ <ean Aerodyna'ic Chord 0'1
C
d
$ Drag Co$efficient
C
d,)
$ >ero &ift Drag Co$efficient
C
-
$ S-ecific fuel consu'-tion 0lbs?h-?hr1
C
&
$ &ift Co$efficient
D $ Drag 01
E $ Endurance 0hr1
e $ "swald efficiency
& $ &ift 01
0&?D1 loiter $ &ift$to$drag ratio at loiter
0&?D1 cruise $ &ift$to$drag ratio at cruise
R $ Range 0k'1
Re $ Reynolds u'ber
S $ *ing Area 0'@1
S
ref
$ Reference surface area
S
wet
$ *etted surface area
S
a
$ A--roach distance 0'1
S
f
$ Flare Distance 0'1
S
fr
$ Free roll Distance 0'1
S
g
$ Ground roll Distance 0'1
T
take$
off $ Thrust at take$off 01
5
cruise
$ 5elocity at cruise 0'?s1
5
stall
$ 5elocity at stall 0'?s1
*
e'-ty
$ E'-ty weight of aircraft 0kg1
*
fuel
$ *eight of fuel 0kg1
Page 5
Design Of Unmanned Combat Aerial Vehicle
*
-ayload
$ !ayload of aircraft 0kg1
*
)
$ ",erall weight of aircraft 0kg1
*?S $ *ing loading 0kg?'@1
Page 6
Design Of Unmanned Combat Aerial Vehicle
-&IN!ODUCION
Page 7
Design Of Unmanned Combat Aerial Vehicle
IN!ODUCION
The structural design of an air-lane actually begins with the flight en,elo-e or 5$
n diagra', which clearly li'its the 'a+i'u' load factors that the air-lane can withstand at any
-articular flight ,elocity. Aowe,er in nor'al -ractice the air-lane 'ight e+-erience loads that
are 'uch higher than the design loads. So'e of the factors that lead to the structural o,erload of
an air-lane are high gust ,elocities, sudden 'o,e'ents of the controls, fatigue load in so'e
cases, bird strikes or lightning strikes. So to add so'e inherent ability to withstand these rare but
large loads, a safety factor of %.6 is -ro,ided during the structural design.
The two 'a/or 'e'bers that need to be considered for the structural design of an
air-lane are wings and the fuselage. As far as the wing design is concerned, the 'ost significant
load is the bending load. So the -ri'ary load carrying 'e'ber in the wing structure is the s-ar
0the front and rear s-ars1 whose cross section is an BI9 section. A-art fro' the s-ars to take the
bending loads, suitable stringers need to take the shear loads acting on the wings.
Cnlike the wing, which is sub/ected to 'ainly unsy''etrical load, the fuselage is 'uch
si'-ler for structural analysis due to its sy''etrical crossing and sy''etrical loading. The
'ain load in the case of fuselage is the shear load because the load acting on the wing is
transferred to the fuselage skin in the for' of shear only. The structural design of both wing and
fuselage begin with shear force and bending 'o'ent diagra's for the res-ecti,e 'e'bers. The
'a+i'u' bending stress -roduced in each of the' is checked to be less than the yield stress of
the 'aterial chosen for the res-ecti,e 'e'ber.
The Structural design in,ol,esD
 Deter'ination of loads acting on aircraftD
a1 5$n diagra' for the design study
b1 Gust and 'aneu,erability en,elo-es
c1 Schrenk9s Cur,e
d1 Critical loading -erfor'ance and final 5$n gra-h calculation
 Deter'ination of loads acting on indi,idual structures
a1 Structural design study E Theory a--roach
b1 &oad esti'ation of wings
c1 &oad esti'ation of fuselage.
d1 <aterial Selection for structural 'e'bers
e1 Detailed structural layouts
Page 8
Design Of Unmanned Combat Aerial Vehicle
f1 Design of so'e co'-onents of wings, fuselage
DAA F!OM AD$)II
 <a+ C
&
F %.6:; and <in C
&
F$).%: G $: H aoa
 <a+ &?D F 4(.42%
 *ing loading F ;6.:(7 kg?'
(
F ;4).)62 ?'
(
 Take off gross weight, *
"
F66))kgF62;66
 E'-ty *eightF2)))kg
 Fuel weight *
f
F %7)) kg
 *ing area, S F 68.88 '
(
 Aigh lift de,ice E nil
 >ero lift drag coeff, C
Do
F ).)%%;
 Drag due to lift coeff, I F ).)%%7
 Cruise ,elocityF %86 '?s
 Cruise altitudeF %))))'
 Root chordF:, Ti- chordF(.%67 '
 *ing s-anF%)'
 &engthF:'
 Coefficient "f &ift C
&
F).)6
 Coefficient "f Drag C
D
F).)%(6
 <ach oF).8
Page 9
Design Of Unmanned Combat Aerial Vehicle
 Airfoil ThicknessF7J
 Stall AngleF:.6 deg
 Ca'ber F 6J
AIM 8 OB%ECIVE
Page 10
Design Of Unmanned Combat Aerial Vehicle
AIM 8 OB%ECIVE
The ob/ecti,e is to design the su-erior un'anned co'bat aerial ,ehicle and it has all kind
of wea-ons which satisfies the 'ission as well as 'ilitary reKuire'ents. This design entangles
with<ach no ).8 which is ne,er been designed -re,iously is considered as the s-ecial feature of
this aircraft. The sco-e of this -ro/ect to design an un'anned co'bat aerial ,ehicle to withstand
the high load factor acting on it and it should be highly resistant towards da'age or failure. It
can achie,e by !ro-er selection of 'aterial and -ro-er design of structural ele'ent.
Page 11
Design Of Unmanned Combat Aerial Vehicle
hree Vie9 Diagram
Page 12
Design Of Unmanned Combat Aerial Vehicle
O$ VIE6
F!ON VIE6
SIDE VIE6
Page 13
Design Of Unmanned Combat Aerial Vehicle
,& V)n DIAG!AM
Page 14
Design Of Unmanned Combat Aerial Vehicle
In accelerated flight, the lift beco'es 'uch 'ore co'-ared to the weight of the aircraft.
This i'-lies a net force contributing to the acceleration. This force causes stresses on the aircraft
structure. The ratio of the lift e+-erienced to the weight at any instant is defined as the Load
Factor 0n1.
Csing the abo,e for'ula, we infer that load factor has a Kuadratic ,ariation with ,elocity.
Aowe,er, this is true only u- to a certain ,elocity.
This ,elocity is deter'ined by si'ultaneously i'-osing li'iting conditions aerodyna'ically
00C&1'a+1 as well as structurally 0n
'a+
1. This ,elocity is called the Corner Velocity, and is
deter'ined using the following for'ula,
In this section, we esti'ate the aerodyna'ic li'its on load factor, and atte'-t to draw
the ,ariation of load factor with ,elocity, co''only known as the 5$n Diagra'. The 5‐n
diagra' is drawn for Sea le,el Standard conditions.
5$n diagra' is used -ri'arily in the deter'ination of co'bination of flight conditions
and load factors to which the air-lane structure 'ust be designed. 5$n diagra' -recisely gi,es
Page 15
Design Of Unmanned Combat Aerial Vehicle
the structural 0'a+i'u' load factor1 and aerodyna'ic 0'a+i'u' C&1 boundaries for a
-articular flight condition.
This en,elo-e de'onstrates the ,ariations of airs-eed ,ersus load factor 05 E n1. In
another word, it de-icts the aircraft li'it load factor as a function of airs-eed. "ne of the -ri'ary
reasons that this diagra' is highly i'-ortant is that, the 'a+i'u' load factorL that is e+tracted
fro' this gra-hL is a reference nu'ber in aircraft structural design. If the 'a+i'u' load factor is
under$calculated, the aircraft cannot withstand flight load safely. For this reason, it is
reco''ended to structural engineers to recalculate the 5$n diagra' on their own as a safety
factor.
!eal :al2es of load factor for se:eral aircraft
Fro' the table the li'it load factor for our CCA5 ranges between
M
li'
0N,e1 F ;
M
li'
0$,e1 F 2
First of all we need to find the
a. Design <aneu,ering S-eed 5
a
b. Design Cruising S-eed 5
c
c. Design Di,ing S-eed 5
d
Calc2lation Of he $ositi:e C2r:e Of V)N Diagram0
Page 16
Design Of Unmanned Combat Aerial Vehicle
 Design <aneu,ering S-eed
5
a
F5
stall
O M
li'
5
a
F (; O;
V
a
; <= m>s
 Design Cruising S-eed
V
c
; -=. m>s
 Design Di,ing S-eed
5
d
F 5
c
N0%)J 5
a
1
5
d
F %86N%8.6F -?,&. m>s
"oad Factor
n F & ? *
& F %?(P
Q
5
Q
(
SC
l
*here
P
Q
F%.((4 Ig?'
2
S F 68.88 '
(
C
l
F%.6:;
 For 5 F (6 '?s
&F26%%(.%(6
n F ).76
 For 5 F 2) '?s
& F 6)67%.47
n F ).;4
 For 5 F 4) '?s
& F :;::8.)4
n F %.776
 For 5 F 7) '?s
& F ()((46.:4
n F 2.84:
 For 5
a
F :8 '?s
& F 4(6((%.:8:
n F 8.::
Page 17
Design Of Unmanned Combat Aerial Vehicle
Calc2lation Of he Negati:e C2r:e Of V)N Diagram0
 Design <aneu,ering S-eed
5
a
F5
stall
O M
li'
5
a
F (; O2
V
a
; .+&,@ m>s
 Design Cruising S-eed
V
c
; -=. m>s
 Design Di,ing S-eed
5
d
F 5
c
N0%)J 5
a
1
5
d
F %86N%8.6
V
d
; -?,&. m>s
"oad Factor
 For 5 F (6 '?s
& F %8667.(6
n F ).22
 For 5 F 2) '?s
& F (6(:%
n F ).48
 For 5 F 4) '?s
& F 44;44
n F ).:4
 For 5 F 7) '?s
& F %)%%(4
n F %.::
 For 5
a
F 6).(2 '?s
& F 8):8(.66
n F %.2%
able Containing the load Factor Val2es For $ositi:e And Negati:e C2r:e&
v n v n
Page 18
Design Of Unmanned Combat Aerial Vehicle
0 0 0 0
25 0.65 25 -0.3253
30 0.9371 30 -0.4685
40 1.6659 40 -0.833
60 3.748 50.23 -1.31
87 7.88 175 -1.31
175 7.88 192.5 -1
192.5 6.88 192.5 6.88
The 5$n -lot is shown below, which clearly e+-lains the load factor beha,ior of the Cn'anned
Aerial 5ehicle
Page 19
Design Of Unmanned Combat Aerial Vehicle
This 5$n diagra' hel-s in -redicting the -ositi,e load li'it, negati,e load li'it, !ositi,e
accelerated stall, negati,e accelerated stall, s-eed li'it, Caution range, Safety li'it, structural
da'age, etc.,
Page 20
Design Of Unmanned Combat Aerial Vehicle
@& GUS ENVE"O$E
Page 21
Design Of Unmanned Combat Aerial Vehicle
Gust is a sudden, brief increase in the s-eed of the wind. Generally, winds are least gusty
o,er large water surfaces and 'ost gusty o,er rough land and near high buildings. *ith res-ect
to aircraft turbulence, a shar- change in wind s-eed relati,e to the aircraftL a sudden increase in
airs-eed due to fluctuations in the airflow, resulting in increased structural stresses u-on the
aircraft.
Shar-$edged gust 0u1 is a wind gust that results in an instantaneous change in direction or
s-eed.
Deri,ed gust ,elocity 0C or C
'a+
1 is the 'a+i'u' ,elocity of a shar-$edged gust that
would -roduce a gi,en acceleration on a -articular air-lane flown in le,el flight at the design
cruising s-eed of the aircraft and at a gi,en air density. As a result a (6J increase is seen in lift
for a longitudinally disturbing gust.
The effect of turbulence gust is to -roduce a short ti'e change in the effecti,e angle of
attack. These changes -roduce a ,ariation in lift and thereby load factor
For ,elocities u- to 5
'a+
, cruise, a gust ,elocity of %6 '?s at sea le,el is assu'ed. For
5
di,
, a gust ,elocity of %) '?s is assu'ed.
Effecti,e gust ,elocityD The ,ertical co'-onent of the ,elocity of a shar-$edged gust that
would -roduce a gi,en acceleration on a -articular air-lane flown in le,el flight at the design
cruising s-eed of the aircraft and at a gi,en air density.
Reference Gust 5elocity 0C
ref
1Rat sea le,el %6'?s.
Design Gust 5elocity 0C
ds
1 R C
ref
S I.
Page 22
Design Of Unmanned Combat Aerial Vehicle
Constructon
The increase in the load factor due to the gust can be calculated by
For cur,e abo,e 5$a+isD
*here ,
I F Gust Alle,iation Factor.
C
'a+
F <a+i'u' deri,ed Gust 5elocity.
a F &ift Cur,e Slo-e for wing.
For cur,e below 5$a+isD
G2st Alle:iation Factor A'B0
"ateral Mass !atio ACB0
*here
g F Acceleration due to Gra,ity.
T F <ean Aerodyna'ic Chord.
Page 23
Design Of Unmanned Combat Aerial Vehicle
c
t
F Chord at ti- F < m
c
r
F Chord at root F ,&-.* m
D ; .&*E
a9 F lift cur,e slo-e for airfoil
∆ F Swee- angle at leading Edge of *ing
a ; +&+=E
Therefore we obtain,
F;@=E&<.
';+&-=*
*e know ,
Page 24
Design Of Unmanned Combat Aerial Vehicle
=y using the eKuations and for ,arious s-eeds of C'a+ we get the following gust lines
Calc2lation Of he $ositi:e And Negati:e C2r:e Of G2st Diagram0
V!"oct# $o%& '%ctor V!"oct# $o%& '%ctor
0 1 0 1
25 0.3125 25 0.3125
30 0.432 30 0.175
40 0.702 40 -0.1
60 1.894 50.23 -0.38
87 5.785 175 -3.81
192.5 3.156 192.5 -0.434
The load factors at the ,arious -oints can be found using the for'ula using the corres-onding
,alues of C
'a+
and the gust en,elo-e is found to be,
Page 25
Design Of Unmanned Combat Aerial Vehicle
Page 26
Design Of Unmanned Combat Aerial Vehicle
E&SC#!EN'GS CU!VE
Page 27
Design Of Unmanned Combat Aerial Vehicle
SchrenHGs C2r:e
&ift ,aries along the wing s-an due to the ,ariation in chord length, angle of attack and swee-
along the s-an. Schrenk9s cur,e defines this lift distribution o,er the wing s-an of an aircraft,
also called si'-ly as &ift Distribution Cur,e. Schrenk9s Cur,e is gi,en by
*here
y
%
is &inear 5ariation of lift along se'i wing s-an also na'ed as &
%.
y
(
is Elli-tic &ift Distribution along the wing s-an also na'ed as &
(.
a ;.
"inear "ift Distrib2tion0
"ift at root
"
root
;,@<E.+ N
"ift at tiI
"
tiI
;*E,*,N
Page 28
Design Of Unmanned Combat Aerial Vehicle
"ift intermediate
"
-
;--+,<@N
"
,
;*E,*,N
=y re-resenting this lift at sections of root and ti- we can get the eKuation for the wing.
EKuation of linear lift distribution for starboard wing
/
-
; )*E,*,4J@E<=@@
EKuation of linear lift distribution for -ort wing we ha,e to re-lace + by E+ in general,
/
-
; *E,*,4J@E<=@@
For the Schrenk9s cur,e we only consider half of the linear distribution of lift and hence we
deri,e y
%
?(
/
-
>, ; )@,-@-4 J -=E@**&.
Page 29
Design Of Unmanned Combat Aerial Vehicle
ElliItic "ift Distrib2tion0
Twice the area under the cur,e or line will gi,e the lift which will be reKuired to
o,erco'e weight
Considering an elli-tic lift distribution we get
*here
b
%
is Actual lift at root
a is wing se'i s-an
&ift at ti-
b
-
;*<*?&=E
EKuation of elli-tic lift distribution
/
,
; -@=@&?.KLA,.)4
,
B
Page 30
Design Of Unmanned Combat Aerial Vehicle
For the re'aining Schrenk9s cur,e we consider the half of the eli-tic distribution of lift and
hence we deri,e y
(
?(
/
,
>, ; *<*&?=.KLA,.)4
,
B
Constr2ction of SchrenHGs C2r:e0
Schrenk9s Cur,e is gi,en by
)@,-@-4 J -=E@**&.J*<*&?=.KLA,.)4
,
B
Page 31
Design Of Unmanned Combat Aerial Vehicle
Substituting different ,alues for + we can get the lift distribution for the wing se'i s-an
"ift distrib2tion table along semi sIan
4 linear elliItic Combined
+ 24:822 7:7;.84 %88:)%.4
+&. 2%77)( 7:26.2)6 %7%8%:.8
- (:448% 782).;42 %467)%
-&. (6(24) 7662.2%4 %(;447.8
, (()(); 7(;7.((% %%2(6(.7
,&. %::)8: 6;4;.27; ;8)%2.7:
@ %66;48 64;6.8;( :)8(%.4
@&. %(2:%7 4;)6.;87 7427).;;
E ;%7:6 4%(%.:44 48;)2.4(
E&. 6;664 (;;4.46 2%(84.(2
. (84(2 ) %28%%.6
Page 32
Design Of Unmanned Combat Aerial Vehicle
.& "OAD ESIMAION ON 6ING
Page 33
Design Of Unmanned Combat Aerial Vehicle
The solution 'ethods which follow Euler9s bea' bending theory 0U?yF<?IFE?R1 use the
bending 'o'ent ,alues to deter'ine the stresses de,elo-ed at a -articular section of the bea'
due to the co'bination of aerodyna'ic and structural loads in the trans,erse direction. <ost
engineering solution 'ethods for structural 'echanics -roble's 0both e+act and a--ro+i'ate
'ethods1 use the shear force and bending 'o'ent eKuations to deter'ine the deflection and
slo-e at a -articular section of the bea'. Therefore, these eKuations are to be obtained as
analytical e+-ressions in ter's of s-an wise location. The bending 'o'ent -roduced here is
about the longitudinal 0+1 a+is.
"oads acting on 9ing0
As both the wings are sy''etric, let us consider the starboard wing at first. There are
three -ri'ary loads acting on a wing structure in trans,erse direction which can cause
considerable shear forces and bending 'o'ents on it. They are as followsD
 &ift force 0gi,en by Schrenk9s cur,e1
 Self$weight of the wing
 *eight of the -ower -lant
 *eight of the fuel in the wing
Shear force and bending moment diagrams d2e to loads along trans:erse
direction at cr2ise condition0
&ift Force gi,en by Schrenk9s Cur,eD
&inear lift distribution 0tra-eViu'1D
/
-
>, ; )@,-@-4 J -=E@**&.
Elli-tic lift distribution 0Kuarter elli-se1D
Page 34
Design Of Unmanned Combat Aerial Vehicle
/
,
>, ; *<*&?=.KLA,.)4
,
B
Aence
)@,-@-4 J -=E@**&.J*<*&?=.KLA,.)4
,
B
"ift distrib2tion AlinearB
"ift distrib2tion AElliIticB
Page 35
Design Of Unmanned Combat Aerial Vehicle
Self)6eight A3@B0 Self)9eight of the 9ing(
*
*ing
F ).(6W *
E'-ty
F).(6W2)))W;.:%
6
6ing
; =@.=&. N
6
$ort
; )@*=<&=. N
6
starboard
; )@*=<&=. N
Assu'ing -arabolic weight distribution
*here b F s-an
*hen we integrate fro' +F) 0root location1 to +Fb 0ti- location1 we get the net weight of -ort
wing.
=y integrating and substituting the known ,alues we get,
Page 36
( )
6 6
(
2
) )
6 y k x · −
∫ ∫
Design Of Unmanned Combat Aerial Vehicle
';)<<&@
Substituting ,arious ,alues of + in the abo,e eKuation we get the self$weight of the wing.
F2el 9eight0
This design has fuel in the wing so we ha,e to consider the weight of the fuel in the wing.
Again by using general for'ula for straight line yF'+ N c we get,
/
f
;EE-&?.4)-<=<&@
Page 37
( )
(
2
::.2 6 y x ·− −
Design Of Unmanned Combat Aerial Vehicle
O:erall "oad distrib2tion0
"oads simIlified as Ioint loads
C2r:e > comIonent Area enclosed >
str2ct2ral 9eight ANB
Centroid Afrom
9ing rootB
3
-
>, ;42668.6 (.):26
Page 38
Design Of Unmanned Combat Aerial Vehicle
3
,
>, (7;88.4 (.%((
6ing 27:2 %.:86
F2el 2);2.72 %.;66
!eaction force and Bending moment calc2lations
MV
A
; +
5
A
$;42668.6$(7;88.4N27:2N2);2.72 F )
V
A
; ?*@=.<&,= N
MM
A
; +
<
A
N027:2W%.:861N02);2.72W%.;661$0;42668.6W(.):261$0(7;88.4W(.%((1 F )
M
A
; ,+-+-?E&E, Nm
ow we know 5A and <A, using this we can find out shear force and =ending 'o'ent.
Page 39
Design Of Unmanned Combat Aerial Vehicle
Shear Force0
=y using the corres-onding ,alues of + in a--ro-riate eKuations we get the -lot of shear force
Page 40
% (
2 0 1
(
BC A
y y
SF y dx V
+
· + −

% (
2 0 1 0 1
(
DC A fuel
y y
SF y dx V y dx
+
· + − +
∫ ∫
% (
2 0 1 2);4
(
AD A
y y
SF y dx V
+
· + − +

2
( ( % (
74(7(
24:822 %284 (6 (6sin ::.2 6 (6
( 6 2
;7286:.(4
BC
x x
SF x x x x x x

¸ _ −
¸ _
1
· + + − + − − +
÷ ÷
¸ ]
¸ ,
¸ ,

(
(().;86 %:8:.2
DC BC
SF SF x x · + −
(
(().;86 %:8:.2 2);2.72
AD BC
SF SF x x x · + − +
Design Of Unmanned Combat Aerial Vehicle
Bending moment
=y substituting the ,alues of + for the abo,e eKuations of bending 'o'ents obtained we can get
a continuous bending 'o'ent cur,e for the -ort wing.
Note0 if we re-lace the + by $+ in each ter' we get the distribution of starboard wing
Page 41
( )
( )
2 ( %
(
4
%.6
( 2 (
%)8%) %84277.6 7:8 (6 (6sin
6
28.6 (6 ::.2 %.77 %(.6 ;7286:.(4 ()%)%;4.4(
%(
BC
x
BM x x x x x
x
x x x x

¸ _
·− + + − +
÷
¸ ,
¸ _
+ − − − + − +
÷
¸ ,
( % (
2
(
BC A A
y y
BM y V dx M
+
¸ _
· + − +
÷
¸ ,
∫∫
DC BC fuel
BM BM y dx · +

2 (
(().;86 ;2;.%6
DC BC
BM BM x x · + −
2);4
AD DC
BM BM x · −
Design Of Unmanned Combat Aerial Vehicle
Shear force and bending moment diagrams d2e to loads along chord9ise
direction at cr2ise condition0
Aerod3namic center) This is a -oint on the chord of an airfoil section where the bending
'o'ent due to the co'-onents of resultant aerodyna'ic force 0&ift and Drag1 is constant
irres-ecti,e of the angle of attack. Aence the forces are transferred to this -oint for obtaining
constant <ac
Shear center) This is a -oint on the airfoil section where if a force acts, it -roduces only bending
and no twisting. Aence the force is transferred to this -oint and the torKue is found.
 Cruise C&F).)6 G 5F %86 '?s
 Cruise CDF ).)%(6
 Angle of attackF $4X 0obtained fro' the lift cur,e slo-e1
 Angle of attack G Vero liftF $6.6º
 *ing lift cur,e slo-e 0a1F ).)84 ?degree
Page 42
Design Of Unmanned Combat Aerial Vehicle
 Co$efficient of 'o'ent about aerodyna'ic centreF $).%6
&ocation of aerodyna'ic centreD
4
ac
>c;+&,.
&ocation of shear centreD
4
sc
>c;+&@
&ift and drag are the co'-onents of resultant aerodyna'ic force acting nor'al to and along the
direction of relati,e wind res-ecti,ely. As a result, co'-onents of the' act in the chordwise
direction also which -roduce a bending 'o'ent about the nor'al 0V1 a+is.5
Co$efficient of force along the nor'al direction,
C
n
;C
"
Cos N JC
D
Sin N
C
n
F 0).)6 W Cos $41 N 0).)%(6 W Sin $41
C
n
F).)6
C
c
;C
"
Sin N JC
D
Cos N
Page 43
Design Of Unmanned Combat Aerial Vehicle
C
c
F 0).)6 W Sin $41 N 0).)%(6 W Cos $41
C
c
F ).%(%(
Chord wise force at root,
F
R
F 0).6W).%(%(W%.((6W%86
(
W:1
F
!
; -<-<=&.=. N>m
Chord wise force at ti-,
F
T
F 0).6W).%(%(W%.((6W%86
(
W(.%671
F

; E?+-&.. N>m
Chord wise force at inter'ediate length,
F
-
; <E--&=. N>m
F
,
; E?+-&.. NKm
=y using y F '+ Nc again we get the eKuation as
3 ; ),.*.&.4 J -.,-?
The abo,e eKuation gi,es the -rofile of load acting chordwise, by integrating this abo,e eKuation
we get a co'-onent of Shear force and again by integrating the sa'e we get the co'-onent of
=ending <o'ent
"oad along chord 9ise direction
Page 44
(
%(:(.86 %6(%; ydx x x · − +

( 2 (
4(8.6: 87);.6 ydx x x · − +
∫∫
Design Of Unmanned Combat Aerial Vehicle
To find fi+ing 'o'ent and the reaction force,
MV
A
; +
V
A
; E+@?E&@, N
MM
A
; +
M
A
; <@*-*&,E Nm
Shear Force0
Page 45
(
%(:(.86 %6(%; 4)2;4.2(
A
SF ydx V
SF x x
· −
· − + −

Design Of Unmanned Combat Aerial Vehicle
Bending Moment0
Page 46
(
2 (
4(8.6: 87);.6 4)2;4.2( :27%7.(4
A A
BM ydx V x M
BM x x x
· − +
· − + − +
∫∫
Design Of Unmanned Combat Aerial Vehicle
TorKue due to nor'al forces and constant -itching 'o'ent at cruise conditionD
The lift and drag forces -roduce a 'o'ent on the surface of cross$section of the wing, otherwise
called a torKue, about the shear center. <o'ent about the aerodyna'ic center gets transferred to
the shear center. The -ower -lant also -roduces a torKue about the shear center on the chord
under which it is located.
Page 47
Design Of Unmanned Combat Aerial Vehicle
orO2e at cr2ise condition0
orO2e d2e to normal force0
*here
c F chord
The eKuation for chord can also be re-resented in ter's of + by taking cF '+Nk
c ; )-&-,<.4 J *&*?EE
Therefore torKue
Page 48
(
%
(
%
(
%
%
W).)6
(
%
W).)6W%.((6W%86 W).)6
(
47.:;
n
T C V c c
T c
T c
ρ ·
·
·
( )
( )
(
%
(
%
(
%
2 (
%
47.:;
47.:; %.%(:6 7.7;44
47.:; %.(82 %6.%% 44.:(
47.:; ).4(4 8.66 44.:(
T c dx
T x dx
T x x dx
T x x x
·
· − +
· − +
1 · − +
¸ ]



Design Of Unmanned Combat Aerial Vehicle
orO2e d2e to chord 9ise force0
orO2e d2e to moment0
Page 49
(
(
W)
)
c
T F
T
·
·
( (
2
( (
2
(
2
2 (
2
%
(
).%6W).6W%.((6W%86 W
(:%2.78
(:%2.78 ).4(4 8.66 44.:(
ac
M
T C V c
T c
T c
T x x x
ρ ·
· −
· −
1 · − − +
¸ ]
Design Of Unmanned Combat Aerial Vehicle
Then the different torKue co'-onents are brought together in a sa'e gra-h to 'ake a
co'-arison
Page 50
Design Of Unmanned Combat Aerial Vehicle
The net torKue will be su' of all the abo,e torKues i.e. torKue due to nor'al force, chordwise
force, -ower-lant and aerodyna'ic 'o'ent
Page 51
Design Of Unmanned Combat Aerial Vehicle
=& MAE!IA" SE"ECION
Page 52
Design Of Unmanned Combat Aerial Vehicle
Aircraft Metals
Inowledge and understanding of the uses, strengths,li'itations, and other characteristics of
structural'etals is ,ital to -ro-erly construct and 'aintain any eKui-'ent, es-ecially airfra'es.
In aircraft 'aintenance and re-air, e,en a slight de,iation fro' design s-ecification, or the
substitution of inferior 'aterials,'ay result in the loss of both li,es and eKui-'ent. The use of
unsuitable 'aterials can readily erase the finestcrafts'anshi-. The selection of the correct
'aterial fora s-ecific re-air /ob de'ands fa'iliarity with the 'ost co''on -hysical -ro-erties
of ,arious 'etals.
$roIerties of Metals
"f -ri'ary concern in aircraft 'aintenance are suchgeneral -ro-erties of 'etals and their alloys
as hardness,'alleability, ductility, elasticity, toughness, density, brittleness, fusibility,
conducti,ity contractionand e+-ansion, and so forth. These ter's are e+-lainedto establish a
basis for further discussion of structural'etals.
#ardness
Aardness refers to the ability of a 'aterial to resistabrasion, -enetration, cutting action, or
-er'anentdistortion. Aardness 'ay be increased by cold working the 'etal and, in the case of
steel and certain alu'inu'alloys, by heat treat'ent. Structural -arts are often
for'ed fro' 'etals in their soft state and are then heattreated to harden the' so that the finished
sha-e will beretained. Aardness and strength are closely associated -ro-erties of 'etals.
Strength
"ne of the 'ost i'-ortant -ro-erties of a 'aterial isstrength. Strength is the ability of a 'aterial
to resistdefor'ation. Strength is also the ability of a 'aterial to resist stress without breaking.
The ty-e of load orstress on the 'aterial affects the strength it e+hibits.
Densit3
Page 53
Design Of Unmanned Combat Aerial Vehicle
Density is the weight of a unit ,olu'e of a 'aterial.In aircraft work, the s-ecified weight of a
'aterial -ercubic inch is -referred since this figure can be used indeter'ining the weight of a
-art before actual 'anufacture.Density is an i'-ortant consideration whenchoosing a 'aterial to
be used in the design of a -artin order to 'aintain the -ro-er weight and balance ofthe aircraft.
Malleabilit3
A 'etal which can be ha''ered, rolled, or -ressedinto ,arious sha-es without cracking,
breaking, orlea,ing so'e other detri'ental effect, is said to be'alleable. This -ro-erty is
necessary in sheet 'etalthat is worked into cur,ed sha-es, such as cowlings,fairings, or wingti-s.
Co--er is an e+a'-le of a 'alleable'etal.
D2ctilit3
Ductility is the -ro-erty of a 'etal which -er'its it tobe -er'anently drawn, bent, or twisted
into ,arioussha-es without breaking. This -ro-erty is essential for'etals used in 'aking wire
and tubing. Ductile 'etalsare greatly -referred for aircraft use because of theirease of for'ing
and resistance to failure under shockloads. For this reason, alu'inu' alloys are used for
cowl rings, fuselage and wing skin, and for'ed ore+truded -arts, such as ribs, s-ars, and
bulkheads.Chro'e 'olybdenu' steel is also easily for'ed intodesired sha-es. Ductility is
si'ilar to 'alleability.
Elasticit3
Elasticity is that -ro-erty that enables a 'etal to returnto its original siVe and sha-e when the
force whichcauses the change of sha-e is re'o,ed. This -ro-ertyis e+tre'ely ,aluable because it
would be highlyundesirable to ha,e a -art -er'anently distorted afteran a--lied load was
re'o,ed. Each 'etal has a -ointknown as the elastic li'it, beyond which it cannot be
loaded without causing -er'anent distortion. In aircraftconstruction, 'e'bers and -arts are so
designed that the 'a+i'u' loads to which they are sub/ected willnot stress the' beyond their
elastic li'its. This desirable-ro-erty is -resent in s-ring steel.
o2ghness
Page 54
Design Of Unmanned Combat Aerial Vehicle
A 'aterial which -ossesses toughness will withstandtearing or shearing and 'ay be stretched or
otherwisedefor'ed without breaking. Toughness is a desirable-ro-erty in aircraft 'etals.
Brittleness
=rittleness is the -ro-erty of a 'etal which allows littlebending or defor'ation without
shattering. A brittle'etal is a-t to break or crack without change of sha-e.=ecause structural
'etals are often sub/ected to shockloads, brittleness is not a ,ery desirable -ro-erty. Cast
iron, cast alu'inu', and ,ery hard steel are e+a'-lesof brittle 'etals.
F2sibilit3
Fusibility is the ability of a 'etal to beco'e liKuid bythe a--lication of heat. <etals are fused in
welding.Steels fuse around (,7)) YF and alu'inu' alloys ata--ro+i'ately %,%)) YF.
Cond2cti:it3
Conducti,ity is the -ro-erty which enables a 'etalto carry heat or electricity. The heat
conducti,ity ofa 'etal is es-ecially i'-ortant in welding because itgo,erns the a'ount of heat
that will be reKuired for-ro-er fusion. Conducti,ity of the 'etal, to a certaine+tent, deter'ines
the ty-e of /ig to be used to controle+-ansion and contraction. In aircraft, electrical conducti,ity
'ust also be considered in con/unction withbonding, to eli'inate radio interference.
hermal E4Iansion
Ther'al e+-ansion refers to contraction and e+-ansionthat are reactions -roduced in 'etals as
the result ofheating or cooling. Aeat a--lied to a 'etal will causeit to e+-and or beco'e larger.
Cooling and heatingaffect the design of welding /igs, castings, and tolerancesnecessary for hot
rolled 'aterial.
Aircraft structures are basically unidirectional. This 'eans that one di'ension, the
length, is 'uch larger than the others $ width or height. For e+a'-le, the s-an of the wing and
Page 55
Design Of Unmanned Combat Aerial Vehicle
tail s-ars is 'uch longer than their width and de-thL the ribs ha,e a 'uch larger chord length
than height and?or widthL a whole wing has a s-an that is larger than its chords or thicknessL and
the fuselage is 'uch longer than it is wide or high. E,en a -ro-eller has a dia'eter 'uch larger
than its blade width and thickness, etc.... For this si'-le reason, a designer chooses to use
unidirectional 'aterial when designing for an efficient strength to weight structure.
Cnidirectional 'aterials are basically co'-osed of thin, relati,ely fle+ible, long fibers which are
,ery strong in tension 0like a thread, a ro-e, a stranded steel wire cable, etc.1
An aircraft structure is also ,ery close to a symmetrical structure. That 'eans the u- and
down loads is al'ost eKual to each other. The tail loads 'ay be down or u- de-ending on the
-ilot raising or di--ing the nose of the aircraft by -ulling or -ushing the -itch controlL the rudder
'ay be deflected to the right as well as to the left 0side loads on the fuselage1. The gusts hitting
the wing 'ay be -ositi,e or negati,e, gi,ing the u- or down loads which the occu-ant
e+-eriences by being -ushed down in the seat ... or hanging in the belt.
=ecause of these factors, the designer has to use a 84 structural 'aterial that can
withstand both tension and co'-ression. Cnidirectional fibers 'ay be e+cellent in tension, but
due to their s'all cross section, they ha,e ,ery little inertia 0we will e+-lain inertia another ti'e1
and cannot take 'uch co'-ression. They will esca-e the load by bucking away. As in the
illustration, you cannot load a string, or wire, or chain in co'-ression.
In order to 'ake thin fibers strong in co'-ression, they are Zglued togetherZ with so'e
kind of an Ze'beddingZ. In this way we can take ad,antage of their tension strength and are no
longer -enaliVed by their indi,idual co'-ression weakness because, as a whole, they beco'e
co'-ression resistant as they hel- each other to not buckle away. The e'bedding is usually a
lighter, softer ZresinZ holding the fibers together and enabling the' to take the reKuired
co'-ression loads. This is a ,ery good structural 'aterial.
*+*- Al2mini2m Allo3
*+*- is a -reci-itation hardening alu'iniu' alloy, containing 'agnesiu' and silicon as its
'a/or alloying ele'ents. It has good 'echanical -ro-erties and e+hibits good weldability. It is
one of the 'ost co''on alloys of alu'iniu' for general -ur-ose use.
Page 56
Design Of Unmanned Combat Aerial Vehicle
It is co''only a,ailable in -re$te'-ered grades such as, 7)7%$" 0solutioniVed1, 7)7%$T7
0solutioniVed and artificially aged1, 7)7%$T76% 0eKui,alent to T7 in rolled stock1.
 Basic IroIerties
7)7% has a density of (.8) g?c'[ 0).);86 lb?in[1.
 Chemical comIosition
The alloy co'-osition of 7)7% isD
Silicon 'ini'u' ).4J, 'a+i'u' ).:J by weight
Iron no 'ini'u', 'a+i'u' ).8J
Co--er 'ini'u' ).%6J, 'a+i'u' ).4)J
<anganese no 'ini'u', 'a+i'u' ).%6J
<agnesiu' 'ini'u' ).:J, 'a+i'u' %.(J
Chro'iu' 'ini'u' ).)4J, 'a+i'u' ).26J
>inc no 'ini'u', 'a+i'u' ).(6J
Titaniu' no 'ini'u', 'a+i'u' ).%6J
"ther ele'ents no 'ore than ).)6J each, ).%6J total
Re'ainder Alu'iniu'
 Mechanical IroIerties
The 'echanical -ro-erties of 7)7% de-end greatly on the te'-er, or heat treat'ent, of the
'aterial.
aB *+*-)+
Annealed 7)7% 07)7%$) te'-er1 has 'a+i'u' tensile strength no 'ore than %:,))) -si 0%(6
<!a1, and 'a+i'u' yield strength no 'ore than :,))) -si 066 <!a1. The 'aterial has
elongation 0stretch before ulti'ate failure1 of (6$2) J.
Page 57
Design Of Unmanned Combat Aerial Vehicle
bB *+*-)E
T4 te'-er 7)7% has an ulti'ate tensile strength of at least 2),))) -si 0()8 <!a1 and yield
strength of at least %7,))) -si 0%%) <!a1. It has elongation of %7J.
cB *+*-)*
T7te'-er 7)7% has an ulti'ate tensile strength of at least 4(,))) -si 0(;) <!a1 and yield
strength of at least 26,))) -si 0(4% <!a1. In thicknesses of ).(6) inch 07.26 ''1 or less, it has
elongation of :J or 'oreL in thicker sections, it has elongation of %)J. T76% te'-er has si'ilar
'echanical -ro-erties. The fa'ous !ioneer -laKue was 'ade of this -articular alloy.
 Uses
7)7% is widely used for construction of aircraft structures, such as wings and fuselages, 'ore
co''only in ho'ebuilt aircraft than co''ercial or 'ilitary aircraft.
7)7% is used for yacht construction, including s'all utility boats.
7)7% is co''only used in the construction of bicycle fra'es and co'-onents.
 6elding
7)7% is highly weldable, for e+a'-le using tungsten inert gas welding 0TIG1 or 'etal inert gas
welding 0<IG1. Ty-ically, after welding, the -ro-erties near the weld are those of 7)7%$), a loss
of strength of around :)J. The 'aterial can be re$heat$treated to restore $T4 or $T7 te'-er for
the whole -iece.
 E4tr2sions
7)7% is also an alloy used in the -roduction of e+trusionsRlong constantEcross$section structural
sha-es -roduced by -ushing 'etal through a sha-ed die.
Page 58
Design Of Unmanned Combat Aerial Vehicle
 Forgings
7)7% is also an alloy that is co''only used in a hot forging. The billet is heated through an
induction furnace and forged using a closed die -rocess. Auto'oti,e -arts, AT5 -arts, and
industrial -arts are /ust so'e of the uses as a forging.
Page 59
Design Of Unmanned Combat Aerial Vehicle
<& DEAI"ED 6ING DESIGN
Page 60
Design Of Unmanned Combat Aerial Vehicle
SIar design0
S-ars are 'e'bers which are basically used to carry the bending and shear loads acting
on the wing during flight. There are two s-ars, one located at %6$()J of the chord known as the
front s-ar, the other located at 7)$8)J of the chord known as the rear s-ar. So'e of the
functions of the s-ar includeD
They for' the boundary to the fuel tank located in the wing.
 The s-ar flange takes u- the bending loads whereas the web carries the shear loads.
 The rear s-ar -ro,ides a 'eans of attaching the control surfaces on the wing.
Considering these functions, the locations of the front and rear s-ar are fi+ed at ).%8c and
).76c res-ecti,ely. The ARA$D 7J airfoil is drawn to scale using any design software and the
chord thickness at the front and rear s-ar locations are found to be 0).:4 ' and ).7( '1, 0).28 '
and ).2)1, 0).(28 ' and ).%66 ' 1 for three sections res-ecti,ely.
The s-ar design for the wing root has been taken because the 'a+i'u' bending 'o'ent
and shear force are at the root. It is assu'ed that the flanges take u- all the bending and the web
takes all the shear effect. The 'a+i'u' bending 'o'ent for high angle of attack condition is
()%)%;4.4( '. the ratio in which the s-ars take u- the bending 'o'ent is gi,en as
*here
h% Fheight of front s-ar
h( Fheight of rear s-ar
FI!S SECION
Page 61
Design Of Unmanned Combat Aerial Vehicle
The yield tensile stress U
y
for 7)7% Al Alloy is (87<!a. The area of the flanges is deter'ined
using the relation
*here
U is yield strength0(87 <-a1
< is bending 'o'ent taken u- by each s-ar0()%)%;4.4(1,
A is the flange area of each s-ar,
V is the centroid distance of the area F h?(
Area of the front S-ar,
A
fs
; +&+,@.
Area of the rear s-ar
A
rs
; +&+-=@
Ass2mItions0
T sections are chosen for to- and botto' flanges of front and rear s-ars.
=oth the flanges are connected by a ,ertical stiffener through s-ot welding
Fro' the buckling eKuation,
Page 62
Design Of Unmanned Combat Aerial Vehicle
the thickness to width ratio of web is found to be ).%)%7. Also fro' \AA&]SIS AD
DESIG "F F&IGAT 5EAIC&E STRCCTCRES by =RCA^, the flange to web width ratio of
the T section .
=y eKuating all the three ,alues of the ratio in area of the section eKuation, the di'ensions of the
s-ar can be found.
SIecification For Front SIar0
t
(
F %.)(7%7W%)
$2
t ; +&+@,+ m
b
f
; +&,+=? m
b
9
; +&@-. m
SIecification For !ear SIar0
t
(
F 8.6862W%)
$4
t ; +&+,=. m
b
f
; +&-=< m
b
9
; +&,=+ m
SECOND SECION
The yield tensile stress U
y
for 7)7% Al Alloy is (87 <!a. The area of the flanges is deter'ined
using the relation
Page 63
Design Of Unmanned Combat Aerial Vehicle
*here
U is yield strength0(87 <-a1
< is bending 'o'ent taken u- by each s-ar0()%)%;4.4(1,
A is the flange area of each s-ar,
V is the centroid distance of the area F h?(
Area of the front S-ar,
A
fs
; +&+E<.
Area of the rear s-ar
A
rs
; +&+@?@
Ass2mItions0
T sections are chosen for to- and botto' flanges of front and rear s-ars.
=oth the flanges are connected by a ,ertical stiffener through s-ot welding
Fro' the buckling eKuation,
the thickness to width ratio of web is found to be ).%)%7. Also fro' \AA&]SIS AD
DESIG "F F&IGAT 5EAIC&E STRCCTCRES by =RCA^, the flange to web width ratio of
the T section .
=y eKuating all the three ,alues of the ratio in area of the section eKuation, the di'ensions of the
s-ar can be found.
SIecification For Front SIar0
Page 64
Design Of Unmanned Combat Aerial Vehicle
t
(
F (.%22W%)
$2
t ; +&+E*, m
b
f
; +&@+ m
b
9
; +&E.E= m
SIecification For !ear SIar0
t
(
F %.8%8W%)
$2
t ; +&+E-E m
b
f
; +&,*? m
b
9
; +&E+=. m
#I!D SECION
The yield tensile stress U
y
for 7)7% Al Alloy is (87 <!a. The area of the flanges is deter'ined
using the relation
*here
U is yield strength0(87 <-a1
< is bending 'o'ent taken u- by each s-ar0()%)%;4.4(1,
A is the flange area of each s-ar,
V is the centroid distance of the area F h?(
Area of the front S-ar,
Page 65
Design Of Unmanned Combat Aerial Vehicle
A
fs
; +&+*E,
Area of the rear s-ar
A
rs
; +&+.,
Ass2mItions0
T sections are chosen for to- and botto' flanges of front and rear s-ars.
=oth the flanges are connected by a ,ertical stiffener through s-ot welding
Fro' the buckling eKuation,
the thickness to width ratio of web is found to be ).%)%7. Also fro' \AA&]SIS AD
DESIG "F F&IGAT 5EAIC&E STRCCTCRES by =RCA^, the flange to web width ratio of
the T section .
=y eKuating all the three ,alues of the ratio in area of the section eKuation, the di'ensions of the
s-ar can be found.
SIecification For Front SIar0
t
(
F 4.%%4:W%)
$2
t ; +&+*E, m
b
f
; +&E-*Em
b
9
; +&*@- m
SIecification For !ear SIar0
t
(
F (.7:(W%)
$2
t ; +&+., m
Page 66
Design Of Unmanned Combat Aerial Vehicle
b
f
; +&@@. m
b
9
; +&.+< m
FI!S SECION
SECOND SECION
Page 67
Design Of Unmanned Combat Aerial Vehicle
#I!D SECION
Page 68
Design Of Unmanned Combat Aerial Vehicle
CONC"USION
The structural design \-art (^ of the C<AED C"<=AT AERIA& 5EAI&E which is a
continuation of the aerodyna'ic design \-art %^ carried out last se'ester, is co'-leted
satisfactorily.
As earlier said, 'any of the 'ethods used in the design are no longer in regular usage, ha,ing
been su--lanted by finite ele'ent 'ethods. The older 'ethods are useful, howe,er for
a--ro+i'ating the correct answers to insure that the finite ele'ent results are in the right \ball
-ark ‟
According to Ray'er, the study of classical 'ethods is useful for learning the ,ocabulary of the
structural design
Page 69
Design Of Unmanned Combat Aerial Vehicle
BIB"IOG!A$#/
%. Ray'er, D.!, Aircraft Design ) a ConceIt2al AIIroach (AIAA educational series second
edition %;;(.
(. T.A.G.<egson ( Aircraft Str2ct2res for engineering st2dents( 4
th
EditionElse,ier &td CSA
())8.
2. E.F.=ruhn ( Anal3sis and design of flight :ehicle str2ct2res(%
st
Edition, tri$state offset
co'-any,CSA,%;82.
4. <icheal Chun$]ung iu( Airframe str2ct2ral design( (
nd
Edition, Aong Iong Con'ilit
!ress &td, Aong Iong, ())%.
6.Anderson, #ohn D, F2ndamentals of Aerod3namics, (nd Edition <cGraw$Aill,
ew ]ork, %;;%.
7.Anderson, #ohn D , Aircraft design and Ierformance b3 Anderson, 2
rd
Edition , Tata
<cGraw$Aill, ew ]ork , ()%).
Page 70

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