calculation of wing loads
TRANSCRIPT
-
7/23/2019 Calculation of Wing Loads
1/55
National Aerospace University
named after N.Ye. Zhukovsky
Kharkiv Aviation Institute
Guide for home taskby course Strength of airplanes and helicopters
CALCULATION OF WING LOADS
Kharkiv, 2015
-
7/23/2019 Calculation of Wing Loads
2/55
2
Manual is dedicated to calculation of loading for highly-aspect ratio wing. Itconsists of the following sections: wing geometric parameters and mass dataestimation; loads calculation and diagrams plotting of shear forces, bending andreduced moments by wing span.
-
7/23/2019 Calculation of Wing Loads
3/55
3
INTRODUCTION
The given home task is continuation of your home task on department"Designing of planes and helicopters ". In this task you have defined take-off mass ofthe plane, its cruiser speed, mass of a wing, mass of fuel, mass of a power-plant,mass of the landing gear, mass of useful load. From this task you have allgeometrical sizes of the plane: the wing area, wing span, swept-back wing, chords ofa wing, position of engines, the landing gear, etc.
The given home task should be included into your course project and after yourcourse project should be included into your baccalaureate project.
For all students we give critical loading condition C - flight on cruise speed VCon cruise altitude HCwith maximal maneuveringload factor n
land airfoil.Students are obliged to follow these requirements according to international
standard:
1. All diagrams at the figures should contain starting and ending values of theillustrated variable (not literal expression of the variable).
2. All diagrams should be built to some scale (the scale should be the same forall diagrams illustrated at one figure). The shape of the curves shouldcorrespond to the functions.
3. All calculations should be made with high accuracy.4. The cover page is executed according to Appendix 5.5. Each table must be on one page.6. Each table and drawing must have heading.7. Standard rule for whole world from the beginning you should write down
formula, next step you should substituted numbers and at last write downresult with units.
8. You should not rewrite reference data, drawings from manual, andexplanations.
9. Home task must be printed.In explanatory book you should print home task content in next execution
sequence:1. Three main views of your plane.2. Table 1. Main data of the plane.
3. Determination of limit load factor.4. Air loads allocation on wing span.5. The wing structure mass load allocation.6. Calculation of the total distributed load on a wing.7. The shear forces, bending and reduced moments diagrams plotting.8. Load checking for wing root cross section.9. Calculation of shear forces position in the design cross section
10. Filling the result table.
-
7/23/2019 Calculation of Wing Loads
4/55
4
1. AIRPLAIN GENERAL DATA
By data your plane you should fill the next table.
Table 1 Main data of the plane
Airplane category Transport (for example)Take-off mass (kg)-MtDesign cruise airspeed (km/h) - VC
Design airspeed (km/h) - VDesign cruise altitude of flight (m) - H
Wing mass (kg) - mwTotal fuel mass (kg) - mfMass of engine (kg)- meMass of main leg of landing gear (kg)- mmlWing area (m2) - Sw Wing span (m) (for swept wing) - LwWing taper
Wing aspect ratio
Swept wing (degree by 25% chord) -0.25
Wing angle of incidence ( degree) - a 2 (for example)
Comment.a. Masses in integer kg.
b. Speeds in integer km/h
-
7/23/2019 Calculation of Wing Loads
5/55
5
1.1. WINGS GENERAL DATA
The airplane category (transport, normal, acrobatic, etc.), take-off mass t aregiven to the final developments assignment.
From previous course project by discipline Airframe the following data is madeout:
1) Wing geometrical data;2) Masses of wing-accommodated units (masses of engines, landing gears,
external and internal fuel tanks, etc.), and each of themes centers of gravity;3) Airfoils relative thickness.4) Cruise speed and cruise height.If the geometrical sizes not specified in exposition (lengths of root and tip chords,
centers of gravity aggregates for units etc.) are possible to remove directly from thedrawing.
It is impossible to select a delta-wing airplane as in the given manual the designprocedure of a highly-aspect wing is explained as the prototype.
1.2. WINGS GEOMETRICAL DATA
Geometrical data of a wing make out from exposition of the airplane. By thesedata it is necessary to execute figure of a half-wing in two projections (top and frontviews).
If a plane has swept-back wing and the sweep angle on the leading edge aremore than 15 it is necessary to enter an equivalent straight wing and all furthercalculations to carry out for this equivalent wing. A straight wing enter by turn of aswept-back half-wing so that the stiffness axis of a straight wing was perpendicular toaxes of a fuselage, thus the root br and tip bt chords sizes decrease, and the sizeLw/2 of a semi span is increased. The sizes Lw/2, br and bt, are required for thefurther calculations and they are taken directly from the figure. At turn of a swept-backwing it is possible to mean, that the stiffness axis is located approximately on distance0.4 bfrom the leading edge where bis the wing chord.
At calculation of Lw/2 semi span size the plane's design is taken into account:a low-wing, a mid-wing or a high-wing monoplane. In these designs carrying ability of
the fuselage part of wing owing to influence of interference is various. For a low-wingmonoplane it is recommended do not take into account bearing ability of an fuselagepart of wing and to accept value equal to distance from the tip of a half-wing(straightened in case of a swept-back wing) up to an onboard rib as Lw/2parameter.For a mid-wing monoplane and a high-wing monoplane in quality semi span wereceive the distance from the tip of a wing up to an axis of the plane as Lw/2. Thewing area Swis determined by the formula:
Sw= 0.5 (br+ bt) Lw. (1.2.1)
-
7/23/2019 Calculation of Wing Loads
6/55
6
The received value of the area must coincide with the area of the airplane withswept-back wing for mid-wing and high-wing airplanes. For convenience of realizationof the further calculations figures of a wing (see fig. 1.2.1, 1.2.2 and 1.2.3) shouldcontain maximum quantity of the information. So, on the top view of a half-wingfollowing characteristic lines are put by dotted, a stroke dotted or by light lines: acenter-of-pressure line, the center of gravity (c.g.) line of cross sections of a wing andlines of spars.
The locations of aggregate's centers of gravity (landing gears, engines, fuel tanksetc.) are indicated by the sign, and value and direction of the appropriate massconcentrated forces - by vectors. The areas are occupied by fuel tanks, on bothprojections are shaded. Centers of tanks weight are also indicated by the
sign. Infigures the geometrical sizes and numerical values of the concentrated forces are putdown.
The explanatory book should contain geometrical and aerodynamic characteristics
of the chosen airfoil. In the final development it is supposed, that all wing crosssections have the same aerofoil.
The relative coordinate of a center-of-pressure line can be found by the scheme:the given design limit loading condition - lift coefficient (for cases B, Cand Dit iscalculated) - the appropriate angle of attack (see ap. 1) - relative coordinate ofcenter-of-pressure line cp.
The wing's gravity center in cross section is located approximately on distance of40 - 45 % of a chord from the leading edge.
Gravity centers coordinates of aggregates are made out from the description ofthe airplane - prototype or chosen independently, being guided by the knowledgeacquired in another subject matters of aggregate's design features. For example, thecenter of gravity for a turbojet is placed in area of the turbine compressor, but not inarea of a jet nozzle.
At gravity center positions estimation of landing gear primary struts if the onesare located in a wing, it is possible to use the following statistical data:ll= (0.2 0.25)Lw, bl= (0.5 0.7) b, where the Lwis a wing span, the bis a wingchord; the ll - is the landing gear base, the bl - is a distance from the leading edgewing to gravity center of the primary strut in the retracted position.
-
7/23/2019 Calculation of Wing Loads
7/55
7
Fig.1.2.1. Diagrams of distributed loads and shear forces
leadin ed e
center of ravit
fuel tankengine
rear spar
q
qtqa
qf Z
Q
Qt
Qd
Qc
0
Lw/2
0
rear spar
br b
front spar
-
7/23/2019 Calculation of Wing Loads
8/55
8
Fig.1.2.2. Diagrams of bending moment Mand reduced moment Mz.
M, kNm
Mtot
Md
Mc
Z
mz, kN Z
Mz, kNm Z
Mz,t
Mz, d
Mz, c
-
7/23/2019 Calculation of Wing Loads
9/55
9
Fig. 1.2.3. Plotting of equivalent straight wihg.
equivalent straight wing
swept wing
axis ofstiffnes
reduced axis
center of
pressure
center ofwing gravity
stiffness axis
Z
center of fuel
gravity
e
Z
d
h
X
rkck
center of gravityfor k-th aggregate
-
7/23/2019 Calculation of Wing Loads
10/55
10
2. DETERMINATION OF LIMIT LOAD FACTOR.
For strength calculation it is necessary to know design airspeeds and loadfactors. For determination of those values for transport airplanes initial conditions aretake-off mass Mt[kg], Lw- wing span, Sw wing area, cruising airspeed of an airplaneVCat the cruise altitude of flight Hc, the wing sweep on the chords fourth 0.25.
In design office (DO) calculations are carried out for all altitude range. In thishome task (HT) you have the cruising airspeed VC and cruising altitude HC fromtechnical data of plane.
For your plane you should take wing airfoil from lecturer. The more speed of theplane, the thinner wing airfoil is. At speeds 400-700 km/h airfoils are recommended
with relative thickness c = 12-15 %. For planes which flies with speeds 700-950 km/h
airfoils are recommended with relative thickness c = 8-12 %.According to ARU-25, FAR-25, JAR-25 maneuvering maximum limit load factor
does not depend from altitude and en-route mass and are determined by the formula:l
y max man
t
108862.1
4536n
M
; (2.1)
where Mtis the design maximum takeoff mass in kilograms; except thatnly max manmay not be less than 2.5 and need not be greater than 3.8.
3. WINGS MASS DATA
Unit's masses (if these data are absent in the description of the prototype) are
set with the help of statistical data for the transport airplanes adduced in tab. 3.1.Thusthe mass of one of primary struts makes usually 45 % from mass of the whole landinggear.
From home task by department "Designing of planes and helicopters" you havetotal fuel mass in wing. The half-wings each have three fuel tanks from safetyconditions as minimal. In this project you can suppose that fuel load is concentratedfor simplicity. From statistic we know that in the first tank is placed 45% from total fuelmass in half-wing, in the second tank 35%, in the third tank 20% (see fig. 3.1).
Approximately by axes xrelative coordinates of centers of mass for tanks are equal
f
x=0.4=40% from leading edge. Approximately by axes z relative coordinates of
centers of mass for the first tanks is equal =0.2, for the second tank - z=0.5, for the
third tank - =0.8.
From the point of view of strength fuel is expedient to place in a wing. Thereforein the final development it is necessary to place the greatest possible fuel content in awing and the rest of fuel to place in a tail unit.
If in a wing there are freights dropped in flight (external fuel tanks) or fuel fromwing fuel tanks is consumed non-uniformly in this case strength of the given crosssection of a wing is calculated from the loadings appropriate not to take-off mass Mt,
but to the flight Mfl one.
-
7/23/2019 Calculation of Wing Loads
11/55
11
Table 3.1.Assemblages and payloads relative mass in the percent share from transport airplane
take-off mass
Take-off mass, tons
t 10 50 100 150 200Assemblages relative mass %
wThe wing
12.2 10.2 9.5 9.1 8.8
lThe landing gear
4.5 4.0 3.8 3.7 3.6
The power plant
ppJet planes
12.3 11.0 10.5 10.2 10.0
pp Turboprops planes16.4 15.6 15.3 15.1 15.0
Total load
tl 43.3 45.8 53.7 61.4 67.6
Note: the total load Mtlis equal to the sum of the fuel and the payload.
Let in a wing there is a freight dropped in flight with weight of G* (the tank-section containing fuel with weight G*), which gravity centre is located in the -cross section with coordinate z (fig. 3.2). Bending moment in the designing crosssection 1-1 depends from the relative -section's position and
force coordinate
which is the resultant of an air load, operating on a segment covered withScutarea,located on the right of the 1-1 cross section. Considering approximately, that airloading is constant on all wing area, we can write down:
cut cut
y t t
w w
S SP M g G
S S (3.1)
wheret t
G M g- is take-off weight of plane, Sw wing area.
If the G* load is present, the 0 bending moment in the 1-1 cross section is
defined by the formula:
0 = *cutt 0 1
w
SG z G ( z z )S
. (3.2)
At the G*loads dropping the force is decreased by the value
* cut
y t
w
SP ( G 2G )
S . (3.3)
Thats why the * loads post dropping bending moment in 1-1 section is equal
to
* = *cut cut t 0 0
w w
S 2SG z G z
S S
.
-
7/23/2019 Calculation of Wing Loads
12/55
12
Fig. 3.1. Disposition of fuel tanks.
Fig. 3.2. Disposition of dropping cargo G*and forcePyrelatively designingcross section I-I.
The 0 and * , moments are equal to each other if the given identity is right*
1 0 cut wz z z z ( 2S / S ) .
If the load has the z z* coordinate, than at its dropping * > 0 , therefore,
the bending moment is increased in the 1-1 section.Thus, to the 1-1 designing cross section a case when freights dropped in flight
are not taken into account, and fuel from tanks sections is consumed which gravitycenters coordinates exceed the z* is more dangerous. At this stage the calculations
1-st fueltank
2-nd fueltank
3-rd fueltank
c.g. c.g.c.g.
xfFrontspar
X
Z
Rear spar
-
7/23/2019 Calculation of Wing Loads
13/55
13
are necessary to perform for the Gfl flight mass which can be received, subtractingfrom the Gt take-off weight the dropped freights and burnt out fuel. Mass of thedropped freights and burnt out fuel in the further calculations is not taken intoaccount.
The z0parameter is defined from the geometrical construction (fig.3.3) or by the
formula
z l b a
b a0
0
3
2 .
For all student designing cross section is assigned under z=0.2. In this case
designing flight mass Mflis equal:
fl t fM M 0.2M , (3.4)
where Mfis total fuel mass.
Fig. 3.3. The scheme of calculation for coordinate z0.
4. WINGS LOADS CALCULATION
The wing is influenced by the air forces allocated on a surface and mass forcescaused by a wing structure and by the wing-arranged fuel, the concentrated forcesfrom the wing - arranged units' masses. Mass forces are parallel to air forces, but are
directed to the opposite side. The fuel tank is expedient to divide on tank-sections andmass of everyone tank-section to concentrate in its gravity center. Then the fuel-distributed load is possible to replace by a set from the concentrated forces.
In FAR, JAR, ARU load factors ny are prescribedin body frame of reference forplanexp, yp, zp(fig. 4.1). We must calculate wing loads in body frame of reference forwingxw, yw, zw(fig. 4.1). From aerodynamic we have speed frame of referencexa, ya,za (fig. 4.1). Therefore we must recalculate loads from body frame of reference forplanexp, yp, zptobody frame of reference for wing xw, yw, zw(fig. 4.1) with using ofspeed frame of referencexa, ya, za
-
7/23/2019 Calculation of Wing Loads
14/55
14
In speed (aerodynamic) coordinate system the resultant air force R has twocomponents: the Y - lift directed perpendicularly to vector of flight speed and the
Xa=Q - drag force directed opposite to flight (fig. 4.1).From designing you should know that wing has wing angle of incidence a. This
angle is angle between body axis for planexp
andbody axis for wingxw
(fig. 4.1).The lift coefficient is calculated in body frame of reference for plane xp, yp, zp
from equation of equilibrium because we have load factor from AR in body frame ofreference for plane:
2
l l H
fl fl y w
Vn M g n G C S
2
.
In the SI we have from this formula:l
fl
y 2
H w
2n M g C
V S
,
where H is air density on HC in SI, V=VC cruise airspeed in m/s, Mfl designing flight mass of plane in kg mass.
By the value of Cyyou can estimate the angle of attack with accuracy within1o,
drag coefficient Cx and the relative coordinate of pressure center Ccp fromaerodynamic characteristic of airfoil (Appendix 1).
The angle between the resultant air force R and Y lift force (fig. 4.1) isequal:
y
x1
y
xa
C
Ctg
C
Carctg
Y
Xarctg
(4.1)
From aerodynamic and designing you must know wing angle of incidence - a(fig. 4.1). You can take this angle from your home task by your airplane or fromstatistic take mean value a=2.
By those values we can calculate resultant air force R (seefig. 4.1):
For strength analysis of wing we must calculate loads in wing frame ofreference by resultant air force R. Lift force in wing frame of reference Yw is equal to:
, (4.2)
where 2 =-- is angle between resultant air force R and lift forceYwin wingframe of reference (seefig. 4.1).
Drag force in wing frame of referenceXwis equal to:
(4.3)
-
7/23/2019 Calculation of Wing Loads
15/55
15
Fig.4.1 Distribution of the aerodynamic load by axes.
On the basis of stated it is enough to plot diagrams of the shear force andbending moment by a wing from effect of the efforts in wing coordinate system. Theshear force and bending moment in the given cross section from the loads in wingframe of reference, we can receive by (4.2, 4.3).
The wing strength is determined in ultimate, instead of limit loading condition.Then also diagrams of shear forces and bending moments it is convenient to plotfrom ultimate, instead from limit loadings. At calculation of ultimate loads in thebeginning we find the ultimate load factor by the formula:
, (4.4)where the nl is the limit load factor for the given design limit loading condition;
the f- is the safety factor.According toAR-25, FAR-25, JAR-25unless otherwise specified, the factor of
safety of f=1.5must be applied to the prescribed limit load are considered external
load on the structure.By the value it is possible to find the ultimate loads. So, lift and a componentalong an axis yp from resultant mass load of a wing structure are found by theformulas:
. . , (4.5)
where the Gw, Mw are weight and mass of wing.In wing frame of reference, we must use (4.2, 4.3) and we have:
.
, [N],
, (4.6)
-
7/23/2019 Calculation of Wing Loads
16/55
16
where the Yw, Pww are resultant air force and resultant inertial force in wing frame ofreference.
Load components acting along the ywaxis from effect of a concentrated massof the aggregate is calculated by the formula:
.
(4.7)
where the Gg, Mag - are the units weight [N] and units mass [kg].
4.1. AIR LOADS ALLOCATION BY THE WING SPAN.
The Y air load in wing frame of reference is allocated according to the relativecirculation low, i.e.
.
,
wL5.0
zz , (4.1.1)
where )z( - is relative circulation, Mfl - is the designing flight mass of the plane(3.4), nu ultimate load factor, Lw wingspan, - is distributed aerodynamic forceby yw.
For distributed load we have next sign convention - if distributed load isdirected upward it has positive sign, if distributed load is directed downward ithas negative sign.
The function )z( depends from many factors, from which in the given work
you should take into account only the dependence from wing taper and sweepback.Relative circulation in this case is determined by the formula:
)z( = )z(f + )z(
, (4.1.2)
where )z(
is amendment on the wing sweep, )z(f function values for flat
straight trapezoidal center-section-less wing are reduced in Appendix 3.This amendment is calculated by the formulas:
)()(
4545
, (4.1.3)
where the
is the designing wing sweep on the chords fourth, angle in degree,(45)is amendment for wing sweep on the chords fourth which is equal 45. This
amendment was given in Appendix 4.
For calculation )z(f you should know wing taper which is designated through
and is equal to:
tr b/b ,
where br is root chord of wing, bt tip chord.
-
7/23/2019 Calculation of Wing Loads
17/55
17
4.2. THE WING STRUCTURE MASS LOAD ALLOCATION.
In approximate calculations it is possible to consider, that load per unit of wingspan mass forces is proportional to chords. Then in wing frame of reference the nextformula is used:
, (4.2.1)
where the b(z) is the wing chord, Mw the wing mass, - distributed inertialforce from wing mass.
The length of wing chord (see column 3 in table 4.3.1) is computed by formulas:
r r tb( z ) b ( b b )z . (4.2.2)
where br is root chord of wing, bt tip chord, - relative coordinate of cross
section (column 2).After the component calculations it is possible to compute the total distributed
wing load qt acting in the direction of the axis yw in the wing coordinate system.Calculations are put into the tab. 4.3.1. At this action the coordinates origin is put intothe wing root cross section. Cross sections are enumerated from the wing root in thewing tip direction beginning from the i = 0.The letter accentuates relative coordinate
wL/z2z . Since on the site = 1 0.9cross sections the qaydiagram is moved
away from straight line, it is necessary to introduce the cross section with the= 0.95coordinate.
4.3. CALCULATION OF THE TOTAL DISTRIBUTED LOAD ON A WING
Table 4.3.1The, ,and qtdistributed loads calculations scheme
i b( z ),m
f
m
kN,q
a
y
m
kN,q
w
y
,tkN
qm
1 2 3 4 5 6 7 8 9
0 0
1 0.1
2 0.2
3 0.34 0.4
5 0.5
6 0.6
7 0.7
8 0.8
9 0.9
10 0.95
11 1.0 0 0 0 0
-
7/23/2019 Calculation of Wing Loads
18/55
18
The total distributed wing load is calculated by the formula:a w
t y yq q q . (4.3.1)
It is also necessary to plot the , and qtfunctions in the same coordinatesystem and in the same scale (see fig. 1.2.1).
In this formula you should summarize in algebraic sense with account of sign.The concentrated mass forces from aggregates Ppw(4.5) also put on figure of a
wing (see fig. 1.2.1). Thus it is convenient to show forces by vectors and to put downa value of these forces.
4.4. THE CHEAR FORCES, BENDING AND REDUCED MOMENTS DIAGRAMSPLOTTING
In the beginning functions shear force )z(Qd and bending moment )z(Md
from the total distributed load qt(z) are found on the wing span. For this purposeintegrals are calculated by tabulated way with trapezoids method.
z
L5.0 w
dz)z(qQ ,
w
z
L2
M Q( z )dz
(4.4.1)
You must yourself to determine signs for q, Q, Maccording to sign conventionfrom mechanic of materials see fig. 4.4.1.
The calculation scheme is given in the tab. 4.4.1, which includes the following values:i 1 ii w
z 0.5( z z )L ; z11=0,(i =10, 9... 1, 0),
, . , , , Q11= 0, (i =10, 9... 1, 0),QQQ iii 1 . Q11= 0; (i = 10, 9... 1, 0),
. , M11=0, (i =10, 9 1, 0)MMM iii 1 ., M11= 0; (i = 10, 9 1, 0) (4.4.2)
where z10 is distance between cross-section number 10 and cross-section number11 and so on; accordingly Q11=0 is increment of shear force in cross-sectionnumber 11 from distributed loads out tip wing. Q10- is increment of shear force incross-section number 10 from distributed loads on site between 10 and 11 cross-sections and so on; Q11=0 is shear force in cross-section number 11 fromdistributed loads out tip wing.Q10 - is shear force in cross-section number 10 fromdistributed loads on site between 10 and 11 cross-sections and so on; M11=0 - isincrement of bending moment in cross-section number 11 from distributed loads outtip wing. M10 - is increment of bending moment in cross-section number 10 fromdistributed loads on site between 10 and 11 cross-sections and so on; M11=0 isbending moment in cross-section number 11 from distributed loads out tip wing; M10-is bending moment in cross-section number 10 from distributed loads on site between
10 and 11 cross-sections and so on.
-
7/23/2019 Calculation of Wing Loads
19/55
19
Fig. 4.4.1. Sign convention for a shear force Qand bending moment M.
The table 4.4.1 is constructed in the assumption that integration implements bythe trapezoids method. The origin is placed in the wing root section. Cross sectionsare numbered from a wing root to a wing tip sincei=0. You can rewrite from previoustable columns 1, 2, 9 in columns 1, 2, 4 accordingly.
After filling of tab. 4.4.1 by the calculated shear forces Qand bending momentsM (on fig.1.2.1 is shown Q and on fig. 1.2.2 is shown M) diagrams are plotted.Diagrams of bending moments are plotted on tension fibers of a wing. Also it is
necessary to result the shear forces and bending moments affected by the Py,agrconcentrated mass forces (in the same coordinate systems that Qand M. and in thesame scale) diagrams. However the sign of these diagrams is opposite to one ofdiagrams Qand M. On fig.1.2.1 diagram Qcfrom concentrated forces is shown (table4.4.2) and on fig. 1.2.2 is shown Mc.
In concentrated mass forces you must include all aggregates of wing engines,landing gears, fuel tanks and so on.
The calculation scheme is given in the tab. 4.4.2, which includes the following
values: Qic= Pw,agr,ifrom (4.7) where i - is number of cross section in which this unit
is placed; in any cross sections Qic = 0. In table 4.4.2 for example concentratedforce is given only in cross section i= 9. You can rewrite columns 1, 2 and 3 fromprevious table.
, , ,, (i = 10, 9... 1, 0),., . , , , M11c=0, (i =10, 9... 1, 0), 4.4.3)
MMM ,1i,1i,i . M11,= 0; (i = 10, 9... 1, 0)where Q11,c=0 is shear force in cross-section number 11 from concentrated loads inthe tip wing. Q10,c - is shear force in cross-section number 10 from concentratedloads. Q9,c- is shear force in cross-section number 9 from concentrated loads which
has jump in this cross-section and two values one previous value - 0and new value
Q>0
M>0
-
7/23/2019 Calculation of Wing Loads
20/55
20
Q9,cand so on; M11,c=0- is increment of bending moment in cross-section number11 from concentrated loads out tip wing. M10,c- is increment of bending moment incross-section number 10 from concentrated loads on site between 10 and 11 cross-sections and so on; M11,c=0 is bending moment in cross-section number 11 fromconcentrated loads out tip wing. M
10,c - is bending moment in cross-section number
10 from concentrated loads on site between 10 and 11 cross-sections and so on. Youmust know that increment of bending moment from concentrated force and bendingmoment from concentrated force you can calculate for next cross-section with numberi-1=8 in our examplesee fig. 1.2.2 and table 4.4.2.
Folding appropriate diagrams algebraically (table 4.4.3), you should plot totaldiagrams Qtotand Mtot(on fig. 1.2.2 are shown by continuous lines). The calculationscheme is given in the tab. 4.4.3, which includes the following values:Qid-is shear force from distributed loads from table 4.4.1;Qic- is shear force from concentrated loads from table 4.4.2;
Qitot=Qid+ Qicwith account signs;Mid- is bending moment from distributed loads from table 4.4.1;Mic- is bending moment from concentrated loads from table 4.4.2;Mtot= Mid+ Micwith account signs.
Table 4.4.1The Qd(z)shear forces and the d(z)bending moment are affected by the qt(z)
distributed load.
ii zi,.
m
,tq
kN
m
Q
id.
kN
Qid
.
kN
Mid.
kNm
Mid.kN m
1 2 3 4 5 6 7 8
0 0 qt0
Q0 Q0 M0 M01
2
34
5
6
78 ...
9 0.9 z9 qt9
Q9 Q
9 M9 M9
10 0.95 z10 qt10
Q10
Q10
=Q10
M10 M10 =M1011 1.0 0 q t11
0 0 0 0
-
7/23/2019 Calculation of Wing Loads
21/55
21
Table 4.4.2The Qic(z)shear forces and the ic(z)bending moment are affected by the
concentrated load.
ii zi,.
m
Qi
.
kN
Qi
.
kN
Mi .
kNm
Mi .
kN m1 2 3 4 5 6 7
0 0 0 Q0 M0 M0
1
2
3
4
5
...
7 Q7=Q9 8 ... Q8=Q9 M8 M8=M89 0.9 z9 Q9 Q9=Q9/0 0 0
10 0.95 z10 0 0 0 0
11 1.0 0 0 0 0 0
Table 4.4.3The total Qtot(z)shear forces and the total itot(z)bending moment are affected
by all forces.
i Qid.kN
Qic.kN
Qitot.kN
Mid.kN*m
Mic.KN*m
Mitot.kNm
1 2 3 4 5 6 7
0
1
2
3
4
5
67
8
9
1011
Those bending moment and shear forces were calculated in the wing systemcoordinate yw, xw, zw(see fig. 4.1).
An origin is placed in the gravity centre of wing cross section on longitudinal axesof wing cross section xw. According to fig. 4.1 it is possible to write down:
-
7/23/2019 Calculation of Wing Loads
22/55
22
, , (4.4.4) ,
.where the 2=- is the angle between total aerodynamic force R and lift
force Yw in wing frame of reference (see 4.1), the Qtotand Mtotare shear force andbending moment in the design cross sections in wing coordinate system, taken fromthe table 4.4.3; the Qyw ,is normal shear force which acts by axes ywin the wingcoordinate system and Qxw is shear forces which acts by axes xw in the wingcoordinate system; the Myw is bending moment in the design cross sections in thewing coordinate system relative axes yw and Mtot = Mxw is bending moment in thedesign cross sections in the wing coordinate system relative axesxw.
If
-
7/23/2019 Calculation of Wing Loads
23/55
23
The distributed reduced moment mzaffected by the distributed loads andis equal:
(4.4.5)where the eand the dare distances from load points andto the reduction axis.
The moment is considered like positive if it acts on pitching relative to thereduction axis. The and dvalues are taken from the fig. 1.2.3.
You can compute their by formulas:
c .g c .g ii i i w i d z tg x b 0.5L z x b .
. . . . ,r t
w
0.8( b b )tg
L
,
where i - is the relative coordinate z for i-thcross section (column 2 from table
4.4.2). c .gx - is relative coordinate of wing center of gravity.Integrating the diagram mz we receive the reduced moments Mzd affected by
the distributed loads. The scheme of calculation is shown in tab. 4.4.4 in whichdesignations is entered:
ii,z1zizid z)mm(5.0M 01111 ,z,z MM ;
z ,i ,d z ,i 1,d z ,i ,dM M M
, (i = 10, 9....., 0).
In the explanatory book you should plot diagrams mzandMz (a diagram Mz isshown on fig.1.2.2 by a dashed line). In a coordinate system for the moments Mzalsoit is necessary to result a diagram of the reduced moments affected by concentrated
masses (on fig. 1.2.2 it is shown by a light line).Affected by a concentrated mass of the i-th aggregate the increment of the
moment z ,c ,i
M is found out by the formula:
,, ,, (4.4.7)where the ri is the distance from the i-th concentrated mass gravity center toreduction axis (it is measured on the drawing). Pw,ag,i is design inertia force by
formula (4.7). The momentz ,,c ,i
M is positive if it acts on pitching. This increment you
have only in point where you have aggregates. In any points this increment is equalzero. Reduced momentMz.c.iis calculated by the formula:
z ,c ,11 z ,c ,11M M 0
;
z ,c ,i z ,c ,i 1 z ,c ,iM M M
. (i = 10, 9.....,0). (4.4.8)
In the point with aggregates we have jumps of reduced moment (see fig. 1.2.2).For this table we take Mz i d from table 4.4.4 and total reduced moment you
should compute with account of signs by the formula:Mz tot= Mz d+ Mz c (4.4.9)
-
7/23/2019 Calculation of Wing Loads
24/55
24
Table 4.4.4Reduced moments calculation scheme from distributed loads
i zi,
m
.,
kN /m
ie
m
,
kN /m
id
m
m iz
kN
zidM
kN
m
M idz
kN m1 2 3 4 5 6 7 8 9
0 , e0 , d0 m 0z M dz01
2
3
4
5
6
78
9
10 z10 , e10 , d10 m 10z M dz10 M dz1011 z11 , e11 , d11 m 11z 0 0
Table 4.4.5Calculation scheme of reduced moment from concentrated loads and from all loads.
I Pw.ag.ikN
rim
Mz.c .ikN*m
Mz.c.ikN*m
MzdikN*m
MztotikN*m
1 2 3 4 5 6 7
0
1
23
4
56
7
8
9
10
11
It is also necessary to plot thez ,tot
M total reduced moment diagram (on fig.
1.2.2 it is shown by the solid line).
-
7/23/2019 Calculation of Wing Loads
25/55
25
4.5. LOAD CHECKING FOR WING ROOT CROSS SECTION
Shear forces, bending and reduced moments values are checked in the rootcross section by the formulas:
,
. . ,,[kN],
, . . , , [kNm],,, . . , (4.5.1)
Here Mflis designing flight mass of plane from (3.4). Mw the wing mass. isthe distance from root section to the air resultant load point; ck- is the distance fromroot section to the k-th aggregate's gravity center and fuel tanks; e and d aredistances from the axis of reduction to points of interception of a plane z=cwith thecenter-of-pressure line and with the c.g. line; rk - is the distance from an axis ofreduction to the k-thaggregate centre of gravity and fuel tanks. In list of aggregatesyou should include all aggregates of wing engines, landing gears, fuel tanks and so
on. Value Cis found with the help of geometrical construction or by the formula:
wL 2
6 1
. (4.5.2)
where the is the wing taper. Values ck.andrkare taken from fig.1.2.3 andparameters eand dvaluesfrom drawing (see fig.1.2.3) in the z = ccross section.
Summation in the right parts of adduced formulas is distributed to allconcentrated masses located in one half-wing. Error of calculation of values,,,,and ,,should not exceed value 1, 10 and 15 % accordingly in relation tothe appropriate values taken from tables in root cross section.
4.6. CALCULATION OF SHEAR FORCES POSITION IN THE DESIGN CROSSSECTION
By values of shear force and the reduced moment it is possible to find outpoint of application for shear force on a wing chord in design cross section:
, ,,, (4.6.1)Thexrcoordinate is count off from the reduction axis. The resultant position is
necessary to be shown by an asterisk on the wings top view (see fig. 1.2.1). Youshould calculate this value only for your design cross section i=2.
-
7/23/2019 Calculation of Wing Loads
26/55
26
Table 4.6.1Results of calculations
Design loading condition C
Design flight mass (kg) - Mfl
Limit load factor - n
l
Safety factor - fUltimate load factor - nu
Fuel mass in 1-st fuel tank (kg) - mf1
Fuel mass in 2-nd fuel tank (kg) ) - mf2
Fuel mass in 3-rd fuel tank (kg) - mf3
Wing span (m) (for equivalent wing)- Lwe
Wing taper
(for equivalent wing)
Wing aspect ratio
(for equivalent wing)
Root wing chord (m) (for equivalent wing) - br
Tip wing chord (m) (for equivalent wing) - bt
Relative thickness of airfoil (%) - c
Number of airfoil
Designing cross section z 0.2
The bending moment for designing cross section (kN*m,form. 4.4.4)
The bending moment for designing cross section (kN*m,form. 4.4.4)
The shear force for designing cross section (kN, form.4.4.4)The shear force for designing cross section (kN, form.4.4.4)
The distance from reduced axis up to application point ofresultant shear force ,(m, form. 4.6.1)The angle of attack
(degree)
The angle between resultant air force and lift force (degree)
Comment.a. Masses in integer kg.
-
7/23/2019 Calculation of Wing Loads
27/55
27
APPENDIXIES
-
7/23/2019 Calculation of Wing Loads
28/55
28
Appendix 1Characteristic of airfoil
The airfoil NACA 0009
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic ofairfoil
X Yt Yb h Cy Ccp
0 0 0 0 -4 -0.30 0.014 -
2.5 1.96 -1.96 3.92 -2 -0.16 0.008 -
5 2.67 -2.67 5.34 0 0.00 0.0064 -
7.5 3.15 -3.15 6.30 2 0.16 0.008 0.240
10 3.51 -3.51 7.02 4 0.30 0.014 0.240
15 4.01 -4.01 8.02 6 0.45 0.020 0.240
20 4.30 -4.30 8.60 8 0.60 0.032 0.240
25 4.46 -4.46 8.92 10 0.74 0.042 0.240
30 4.50 -4.50 9.00 12 0.90 0.059 0.240
40 4.35 -4.35 8.70 14 1.05 0.077 0.240
50 3.97 -3.97 7.94 16 1.19 0.098 0.240
60 3.42 -3.42 6.84 18 1.30 0.120 0.24
70 2.75 -2.75 5.50 20 1.17 0.165 0.266
80 1.97 -1.97 3.94 21 1.06 0.280 0.32490 1.09 -1.09 2.18 22 0.96 0.340 0.362
100 0 0 0 24 0.91 0.392 0.383
-
7/23/2019 Calculation of Wing Loads
29/55
29
The airfoil NACA 0012
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic of
airfoil
X Yt Yb h Cy Ccp
0 0 0 0 -4 -0.30 0.015 -
2.5 2.62 -2.62 5.24 -2 -0.15 0.009 -
5 3.56 -3.56 0.00 0 0.00 0.007 -
7.5 4.20 -4.20 8.40 2 0.15 0.009 0.244
10 4.68 -4.68 9.36 4 0.30 0.015 0.244
15 5.34 -5.34 10.68 6 0.445 0.020 0.244
20 5.74 -5.74 11.48 8 0.60 0.033 0.244
25 5.94 -5.94 11.88 10 0.745 0.041 0.244
30 6.00 -6.00 12.00 12 0.90 0.059 0.244
40 5.80 -5.80 11.60 14 1.045 0.075 0.244
50 5.29 -5.29 10.58 16 1.20 0.096 0.244
60 4.56 -4.56 9.12 18 1.32 0.119 0.244
70 3.66 -3.66 7.32 20 1.46 0.142 0.244
80 2.62 -2.62 5.24 21 1.55 0.173 0.244
90 1.45 -1.45 2.90 22 1.20 0.262 0.301
100 0 0 0 24 1.09 0.322 0.335
-
7/23/2019 Calculation of Wing Loads
30/55
30
The airfoil NACA 0015
Geometric characteristic ofairfoil
(in %from chord)
Aerodynamic characteristic ofairfoil
X Yt Yb h Cy Ccp
0 0 0 0 -4 -0.30 0.014 -
2.5 3.27 -3.27 6.54 -2 -0.15 0.009 -
5 4.44 -4.44 8.88 0 0.00 0.007 0.238
7.5 5.25 -5.25 10.50 2 0.15 0.009 0.238
10 5.85 -5.85 11.70 4 0.30 0.014 0.238
15 6.68 -6.68 13.36 6 0.45 0.020 0.238
20 7.17 -7.17 14.34 8 0.60 0.031 0.238
25 7.43 -7.43 14.86 10 0.74 0.042 0.238
30 7.50 -7.50 15.00 12 0.89 0.060 0.238
40 7.25 -7.25 14.50 14 1.02 0.075 0.233
50 6.62 -6.62 13.24 16 1.17 0.095 0.238
60 5.70 -5.70 11.40 18 1.30 0.119 0.238
70 4.58 -4.58 9.16 20 1.42 0.140 0.238
80 3.28 -3.28 6.56 21 1.55 0.178 0.238
90 1.81 -1.81 3.62 22 1.29 0.210 0.284
100 0 0 0 24 1.21 0.269 0.300
-
7/23/2019 Calculation of Wing Loads
31/55
31
The airfoil NACA-21012
Geometric characteristic of airfoil(in %from chord) Aerodynamic characteristic of airfoil
X Yt Yb h Cx Cm Ccp
0 0 0 0 -4 -0.26 0.014 -0.062
1.25 2.95 -0.90 3.85 -2 -0.20 0.0095 -0.024 ---
2.5 3.72 -1.45 5.17 0 0.035 0.0071 0.0072 0.206
5 4.67 -2.44 8.11 2 0.20 0.011 0.046 0.230
7.5 5.28 -.12 8.40 4 0.36 0.017 0.0814 0.232
10 5.72 -3.64 9.36 6 0.50 0.0225 0.1165 0.233
15 6.33 -4.36 10.69 8 0.65 0.034 0.152 0.23420 6.67 -4.80 11.47 10 0.80 0.047 0.187 0.234
25 6.82 -5.07 11.89 12 0.95 0.065 0.222 0.234
30 6.82 -5.18 12.00 14 1.09 0.083 0.255 0.233
40 6.52 -5.10 11.622 16 1.23 0.114 0.288 0.234
50 5.89 -4.71 10.60 18 1.36 0.128 0.319 0.234
60 5.04 -4.09 9.13 20.8 1.50 0.160 0.352 0.234
70 4.03 -3.30 7.33 21 1.52 0.182 0.354 0.234
80 2.86 -2.38 5.24 21 1.20 0.252 0.352 '0.293
90 1.5757 -1.32 2.89 22 1.12 0.281 0.353 0.31595 0.87 -0.75 1.62 24 1.02 0.341 0.360 0.353
100 0 0 0 26 0.96 0.392 0.346 0.360
30 0.88 0.464 0.347 0.394
-
7/23/2019 Calculation of Wing Loads
32/55
32
The airfoil NACA-22012
Geometrical characteristic of airfoil(in % from chord)
Aerodynamic characteristic of airfoil
X Yt Yb Ym h Cy Cx Cm Ccp
0 0 0 0 0 -4 -0.25 0.0092 -0.054 ---
1.25 2.84 -1.10 0.87 3.94 -2 -0.10 0.008 -0.019 ---
2.5 3.76 -1.60 1.08 5.36 0 0.05 0.0073 0.017 0.336
5 4.97 -2.17 1.40 7.14 2 0.20 0.009 0.052 0.260
7.5 5.71 -2.68 1.52 8.39 4 0.37 0.016 0.092 0.249
10 6.22 -3.15 1.54 9.37 6 0.50 0.022 0.123 0.246
15 6.80 -3.89 1.46 10.69 8 0.66 0.034 0.161 0.244
20 7.11 -4.38 1.37 11.49 10 0.80 0.048 0.195 0.244
25 7.23 -4.66 1.29 11.89 12 0.97 0.063 0.237 0.244
30 7.22 -4.80 1.21 12.02 14 1.10 0.0820.268
0.244
40 6.85 -4.76 1.05 11.61 16 1.24 0.105 0.300 0.244
50 6.17 -4.42 0.88 10.59 18 1.38 0.130 0.337 0.244
60 5.27 -3.85 0.71 9.12 20 1.50 0.156 0.366 0.244
70 4.19 -3.14 0.53 7.33 22 1.60 0.180 0.389 0.245
80 2.99 -2.26 0.37 5.25 22 1.26 0.252 0.368 0.292
90 1.63 -1.26 0.19 2.89 24 1.13 0.320 0.378 0.334
95 0.89 -0.71 0.09 1.60 26 1.04 0.372 0.377 0.363
100 0 0 0 0 30 0.94 0.454 0.372 0.395
-
7/23/2019 Calculation of Wing Loads
33/55
33
The airfoil NACA - 2210
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic of airfoil
X Yt Yb Ym h Cy Ccp
0 0 0 0 0 0.120 0.010 0.467
2.5 2.92 -1.52 0.70 4.44 2 0.262 0.013 0.339
5 4.02 -1.96 1.03 5.98 4 0.403 0.020 0.304
7.5 4.83 -2.17 1.33 7.00 6 0.545 0.029 0.291
10 5.51 -2.47 1.59 7.98 8 0.688 0.043 0.27915 6.40 -2.50 1.96 9.00 10 0.827 0.058 0.273
20 6.78 -2.78 2.00 9.56 12 0.960 0.074 0.267
25 6.94 -2.96 1.99 9.90 14 1.080 0.094 0.264
30 6.97 -3.03 1.97 10.00 16 1.195 0.114 0.260
40 6.75 -2.95 1.90 9.70 18 1.250 0.130 0.257
50 6.16 -2.72 1.72 8.88 20 1.162 0.163 0.283
60 5.34 -2.30 1.52 7.64 21 1.158 0.207 0.299
70 4.29 -1.81 1.24 6.10 22 1.130 0.278 0.317
80 3.19 -1.41 0.89 4.60
90 1.60 -0.74 0.43 2.34
100 0 0 0 0
-
7/23/2019 Calculation of Wing Loads
34/55
34
The airfoil NACA -2212
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic of airfoil
X Yt Yb h Cy
Ccp
0 0 0 0 -4 -0.17 0.0110
2.5 3.35 -1.96 5.31 -2 -0.01 0.0088
5 4.62 -2.55 7.17 0 0.13 0.0088 0.476
7.5 5.55 -2.89 8.44 2 0.29 0.0135 0.348
10 6.27 -3.11 9.38 4 0.43 0.0195 0.316
15 7.25 -3.44 10.69 6 0.59 0.028 0.300
20 7.74 -3.74 11.48 8 0.73 0.040 0.289
25 7.93 -3.94 11.87 10 0.88 0.055 0.283
30 7.97 -4.03 12.00 12 1.02 0.072 0.278
40 7.68 -3.92 11.60 14 1.16 0.092 0.275
50 7.02 -3.56 10.58 16 1.30 0.113 0.272
60 6.07 -3.05 9.12 18 1.42 0.139 0.270
70 4.90 -2.43 7.33 20 1.54 0.162 0.269
80 3.52 -1.74 5.26 21 1.60 0.203 0.268
90 1.93 -0.97 2.90 22 1.40 0.240 0.300
100 0 0 0 24 1.31 0.310 0.327
-
7/23/2019 Calculation of Wing Loads
35/55
35
The airfoil NACA -2214
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic of airfoil
X Yt Yb h Cy
Ccp
0 0 0 0 -5.12 -0.229 0.0162 0.104
2.5 3.8 -2.41 6.21 -3.27 -0.106 0.0131 -
5 5.21 -3.15 8.36 -1.51 0.017 0.0116 -
7.5 6.23 -3.58 9.81 0.3 0.139 0.0127 0.418
10 7.06 -3.90 10.96 2.14 0.264 0.0165 0.327
15 8.20 -4.28 12.48 4.01 0.396 0.0235 0.299
20 8.69 -4.69 13.38 5.79 0.535 0.0325 0.285
25 8.92 -4.94 13.86 7.65 0.678 0.0446 0.279
30 8.97 -5.03 14.00 9.5 0.825 0.0596 0.275
40 8.68 -4.89 13.57 11.39 0.943 0.0764 0.275
50 7.88 -4.44 12.32 13.15 1.057 0.0923 0.261
60 6.05 -3.71 10.66 14.99 1.154 0.110 0.261
70 5.5 -3.02 8.52 16.94 1.226 0.1302 0.260
80 3.96 -2.18 6.44 18.65 1.257 0.1672 0.263
90 2.07 -1.21 3.28 20.43 1.214 0.2041 0.285
100 0 0 0 22.22 1.190 0.2359 0.302
-
7/23/2019 Calculation of Wing Loads
36/55
36
The airfoil NACA-23012
Geometric characteristic of airfoil(in % from chord)
Aerodynamic characteristic of airfoil
X Yt Yb Ym h Cy Cm Ccp
0 0 0 0 0 -4 -0.22 0.013 0.046 -
1.25 2.67 -1.23 0.77 3.90 -2 -0.08 0.00955 -0.011 -
2.5 3.61 -1.71 0.95 5.32 0 0.085 0.0071 0.028 0.330
5 4.91 -2.26 1.33 7.17 2 0.24 0.012 0.065 0.270
7.5 5.80 -2.61 1.60 8.41 4 0.385 0.018 0.099 0.257
10 6.43 -2.92 1.76 9.35 6 0.53 0.025 0.134 0.253
15 7.19 -3.50 1.85 10.69 8 0.68 0.035 0.169 0.248
20 7.50 -3.97 1.77 11.47 10 0.835 0.050 0.206 0.24725 7.60 -4.28 1.66 11.88 12 0.98 0.067 0.242 0.247
30 7.55 -4.46 1.54 12.01 14 1.12 0.088 0.275 0.245
40 7.14 -4.48 1.33 11.62 16 1.28 0.108 0.313 0.244
50 6.41 -4.17 1.12 10.58 18 1.40 0.130 0.342 0.245
60 5.47 -3.67 0.90 9.14 20 1.53 0.159 0.372 0.243
70 4.36 -3.00 0.68 7.36 22 1.63 0.186 0.396 0.243
80 3.08 -2.16 0.46 5.24 22 1.31 0.255 0.382 0.292
90 1.68 -1.23 0.23 2.71 24 1.19 0.317 0.394 0.33195 0.92 -0.70 0.11 1.62 26 1.045 0.390 0.375
100 0 0 0 0 30 0.98 0.393 0.400
-
7/23/2019 Calculation of Wing Loads
37/55
37
The airfoil NACA - 2309
Geometric characteristic of airfoil(in % from chord)
Aerodynamic characteristic of airfoil
X Yt Yb Ym h Cy Ccp
0 0 0 0 -2 0.00 0.009 -
2.5 2.39 -1.58 0.405 3.97 0 0.15 0.008 0.490
5 3.36 -2.01 0.675 5.37 2 0.30 0.012 0.370
7.5 4.09 -2.24 0.925 6.33 4 0.45 0.020 0.331
10 4.67 -2.38 1.145 7.05 6 0.60 0.028 0.310
15 5.54 -2.50 1.52 8.04 8 0.75 0.040 0.299
20 6.08 -2.52 1.78 8.60 10 0.90 0.054 0.290
25 6.37 -2.51 1.93 8.88 12 1.06 0.074 0.285
30 6.50 -2.50 2.00 9.00 14 1.20 0.094 0.282
40 6.32 -2.39 1.965 8.71 16 1.34 0.120 0.279
50 5.82 -2.13 1.845 7.95 18 1.44 0.142 0.278
60 5.07 -1.78 1.645 6.85 20 1.51 0.188 0.277
70 4.11 -1.38 1.365 5.49 21 1.40 0.238 0.307
80 2.96 -0.97 0.995 3.93 22 1.30 0.310 0.342
90 1.64 -0.54 0.55 2.18 24 1.20 0.380 0.375
100 0 0 0 0
-
7/23/2019 Calculation of Wing Loads
38/55
38
The airfoil NACA 2312
Geometric characteristic of airfoil
(in %from chord)
Aerodynamic characteristic
of airfoilX Yt Yb Ym h Cy Ccp
0 0 0 0 0 -2 0.00 0.003 -
2.5 3.11 -2.16 0.475 5.27 0 0.13 0.011 0.527
5 4.31 -2.85 0.73 7.16 2 0.30 0.014 0.377
7.5 5.18 -3.26 0.96 8.14 4 0.44 0.020 0.338
10 5.86 -3.52 1.17 9.38 6 0.58 0.028 0.310
15 6.89 -3.82 1.535 10.71 8 0.74 0.040 0.297
20 7.54 -3.94 1.80 11.48 10 0.90 0.056 0.289
25 7.88 -3.99 1.945 11.87 12 1.04 0.064 0.284
30 8.00 -4.10 2.00 12.00 14 1.18 0.090 0.273
40 7.77 -3.84 1.965 11.61 16 1.30 0.114 0.279
50 7.14 -3.45 1.845 10.59 18 1.42 0.140 0.276
60 6.21 -2.92 1.645 9.13 20 1.54 0.164 0.276
70 5.02 -2.31 1.355 7.33 21 1.61 0.200 0.276
80 3.62 -1.63 0.995 5.25 22 1.47 0.247 0.302
90 2.00 -1.91 0.545 2 91 24 1.36 0.300 0.316
100 0 0 0 0 26 1.24 0.360 0.351
-
7/23/2019 Calculation of Wing Loads
39/55
39
The airfoil NACA -2315
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic of airfoil
X Yt Yb h Cy
Ccp
0 0 0 0 -4 -0.19 0.013
2.5 3.85 -2.74 6.59 -2 -0.01 0.010
5 5.26 -3.66 8.92 0 0.13 0.011 0.510
7.5 6.28 -4.25 10.74 2 0.30 0.014 0.357
10 7.08 -4.66 11.74 4 0.42 0.020 0.324
15 8.25 -5.13 13.38 6 0.53 0.030 0.302
20 8.97 -5.38 14.35 8 0.72 0.040 0.292
25 9.36 -5.48 14.84 10 0.86 0.054 0.285
30 9.50 -5.50 15.00 12 1.01 0.072 0.279
40 9.22 -5.29 14.51 14 1.10 0.090 0.277
50 8.47 -4.77 13.24 16 1.30 0.110 0.273
60 7.66 -4.06 11.42 18 1.40 0.140 0.274
70 5.95 -3.22 9.17 20 1.53 0.162 0.274
80 4.29 -2.28 6.57 21 1.54 0.172 0.275
90 2.39 -1.26 3.62 22 1.44 0.230 0.297
95 1.30 -0.72 2.02 24 1.40 0.280 0.314
100 0 0 0 26 1.34 0.340 0.324
-
7/23/2019 Calculation of Wing Loads
40/55
40
The airfoil NACA-2412
Geometric characteristic of airfoil(in % from chord)
Aerodynamic characteristic of airfoil
X Yt Yb Ym h Cy C Cm Ccp
0 0 0 0 0 -4 -0.18 0.012 0.001 --
1.25 2.15 -1.65 0.25 3.80 -2 0.00 0.0088 0.044 __
2.5 2.99 -2.27 0.36 5.26 0 0.13 0.010 0.076 0.588
5 4.13 -3.01 0.56 7.14 2 0.29 0.0128 0.119 0.397
7.5 4.96 -3.46 0.75 8.42 4 0.42 0.020 0.150 0.35510 5.63 -3.75 0.94 9.38 6 0.58 0.030 0.189 0.326
15 6.61 -4.10 1.255 10.71 8 0.72 0.040 0.224 0.311
20 7.26 -4.23 1.515 11.49 10 0.88 0.052 0.264 0.300
25 7.67 -4.22 1.725 11.89 12 1.00 0.074 0.294 0.294
30 7.88 -4.12 1.88 12.00 14 1.16 0.090 0.334 0.288
40 7.80 -3.80 2.00 11.60 16 1.30 0.112 0.370 0.281
50 7.24 -3.34 1.95 10.58 18 1.40 0.140 0.392 0.281
60 6.36 -2.76 1.80 9.12 20 1.52 0.160 0.424 0.279
70 5.18 -2.14 1.52 7.32 22 1.60 0.192 0.444 0.278
80 3.75 -1.50 1.125 5.25 24 1.34 0.300 0.436 0.325
90 2.08 -0.82 0.63 2.90 26 1.20 0.360 0.428 0.355
95 1.14 -0.48 0.33 1.62 28 1.10 0.414 0.377
100 0 0 0 0
-
7/23/2019 Calculation of Wing Loads
41/55
41
The airfoil NACA-2415
Geometric characteristic of airfoil (in% from chord)
Aerodynamic characteristic ofairfoil
X Yt Yb Ym h Cy Cx Cm Ccp
0 0 0 0 0 -4 -0.18 0.013 -0.050
1.25 2.71 -2.06 0.33 4.77 -2 -0.02 0.010 0.035
2.5 3.71 -2.86 0.43 6.57 0 0.13 0.012 0.0735 0.557
5 5.07 -3.84 0.62 8.91 2 0.28 0.016 0.110 0.392
7.5 6.06 -4.47 0.80 10.53 4 0.42 0.020 0.145 0.345
10 6.83 -4.90 0.87 11.73 6 0.57 0.030 0.182 0.320
15 7.97 -5.42 1.28 13.39 8 0.71 0.042 0.218 0.307
20 8.70 -5.66 1.52 14.36 10 0.86 0.056 0.255 0.297
25 9.17 -5.70 1.74 14.87 12 1.00 0.071 0.288 0.288
30 9.38 -5.62 1.88 15.00 14 1.15 0.090 0.326 0.283
40 9.25 -5.25 2.00 14.50 16 1.28 0.112 0.360 0.281
50 8.57 -4.67 1.95 13.24 18 1.40 0.136 0.390 0.278
60 7.50 -3.90 1.80 11.40 20 1.50 0.160 0.415 0.276
70 6.10 -3.05 1.53 9.15 22 1.54 0.192 0.425 0.276
80 4.41 -2.15 1.13 6.56 24 1.41 0.280 0.441 0.313
90 2.45 -1.17 0.64 3.62 26 1.31 0.332 0.439 0.335
95 1.34 -0.68 0.33 2.02 28 1.20 0.383 0.425 0.354
100 0 0 0 0 30 1.10 0.415 0.378
-
7/23/2019 Calculation of Wing Loads
42/55
42
The airfoil NACA-2409
Geometric characteristic of airfoil(in % from chord)
Aerodynamic characteristic ofairfoil
X Yt Yb Ym h Cy Cx Cm Ccp
0 0 0 0 0
1.25 1.62 -1.23 0.195 2.85 -4 -0.192 0.012 -0.004
2.5 2.27 -1.66 0.305 3.93 -2 0.00 0.008 0.044
5 3.2 -2.15 0.525 5.35 0 0.13 0.008 0.076 0.588
7.5 3.87 -2.44 0.715 6.31 2 0.29 0.0128 0.118 0.39710 4.43 -2.60 0.915 7.03 4 0.43 0.020 0.150 0.352
15 5.25 -2.77 1.24 8.02 6 0.58 0.028 0.188 0.326
20 5.81 -2.79 1.51 8.60 8 0.72 0.040 0.224 0.311
25 6.18 -2.74 1.72 8.92 10 0.88 0.054 0.264 0.300
30 6.38 -2.62 1.88 9.00 12 1.02 0.070 0.298 0.293
40 6.35 -2.35 2.00 8.70 14 1.18 0.090 0.336 0.287
50 5.92 -2.02 1.95 7.94 16 1.30 0.112 0.370 0.284
60 5.22 -1.63 1.795 6.85 18 1.43 0.140 0.402 0.281
70 4.27 -1.24 1.515 5.51 20 1.50 0.180 0.416 0.277
80 3.10 -0.85 1.125 3.95 22 1.30 0.270 0.444 0.342
90 1.72 -0.47 0.625 2.19 24 1.16 0.370 0.430 0.371
95 0.94 -0.28 0.33 1.22 26 1.08 0.420 0.389
100 0 0 0 0 28 1.00 0.410 0.410
-
7/23/2019 Calculation of Wing Loads
43/55
43
The airfoil NACA-23015
Geometric characteristic of airfoil
(in % from chord)
Aerodynamic characteristic of
airfoilX Yt Yb Ym h Cy Cx Cm Ccp
0 0 0 0 -4 -0.21 0.014 -0.042
1.25 3.34 -1.54 0.90 4.90 -2 -0.06 0.011 -0.006
2.5 4.44 -2.25 1.095 6.69 0 0.09 0.0082 0.029 0.332
5 5.89 -3.04 1.425 8.93 2 0.23 0.014 0.063 0.274
7.5 6.91 -3.61 1.65 10.52 4 0.39 0.018 0.101 0.259
10 7.64 -4.09 1.78 11.73 6 0.53 0.027 0.135 0.255
15 8.52 -4.84 1.84 13.36 8 0.69 0.038 0.173 0.251
20 8.92 -5.41 1.76 14.33 10 0.83 0.051 0.206 0.248
25 9.08 -5.78 1.65 14.86 12 0.98 0.068 0.242 0.247
30 9.05 -5.96 1.55 15.01 14 1.13 0.088 0.278 0.246
40 8.59 -5.92 1.34 14.51 16 1.27 0.108 0.312 0.246
50 7.74 -5.50 1.12 13.24 18 1.40 0.132 0.343 0.245
60 6.61 -4.81 0.90 11.42 20 1.52 0.158 0.372 0.244
70 5.25 -3.91 0.67 9.16 22.2 1.61 0.190 0.393 0.244
80 3.73 -2.83 0.45 6.56 22.2 1.36 0.245 0.375 0.275
90 2.04 -1.59 0.23 3.63 24 1.27 0.288 0.379 0.298
95 1.12 -0.90 0.12 2.02 26 1.18 0.338 0.382 0.324
100 0 0 0 0 30 1.01 0.372 0.368
-
7/23/2019 Calculation of Wing Loads
44/55
44
The airfoil NACA-23009
Geometric characteristic of airfoil(in % from chord)
Aerodynamic characteristic of airfoil
X Yt Yb Ym h Cy Cx Cm Ccp
0 0 0 0 -4 -0.22 0.012 -0.0415
1.25 2.04 -0.91 0.07 2.95 -2 -0.09 0.009 -0.013
2.5 2.83 -1.19 0.82 4.02 0 0.09 0.0066 0.031 0.344
5 3.93 -1.44 1.25 5.37 2 0.225 0.011 0.063 0.280
7.5 4.70 -1.63 1.54 6.33 4 0.39 0.0165 0.103 0.26410 5.26 -1.79 1.74 7.05 6 0.53 0.023 0.137 0.258
15 5.85 -2.17 1.84 9.02 8 0.69 0.035 0.175 0.254
20 6.06 -2.55 2.26 8.61 10 0.83 0.050 0.209 0.252
25 6.11 -2.80 1.66 8.91 12 0.975 0.066 0.244 0.250
30 6.05 -2.96 1.55 9.01 14 1.12 0.088 0.279 0.249
40 5.69 -3.03 1.33 8.72 16 1.29 0.110 0.320 0.248
50 5.09 -2.86 1.12 7.95 18 1.40 0.133 0.347 0.247
60 4.32 -2.53 0.89 6.85 20.3 1.55 0.170 0.383 0.247
70 3.42 -2.08 0.72 5.50 20.3 1.30 0.232 0.383 0.295
80 2.41 -1.51 0.45 3.92 22 1.25 0.290 0.401 0.320
90 1.31 -0.86 0.23 2.17 24 1.16 0.360 0.420 0.362
95 0.72 -0.50 0.11 1.22 26 1.08 0.410 0.380
100 0 0 0 0 30 0.95 0.389 0.409
-
7/23/2019 Calculation of Wing Loads
45/55
45
The airfoil NACA-32012
Geometric characteristic of airfoil (in %from chord)
Aerodynamic characteristic ofairfoil
X Yt Yb Ym h Cy Cx Cm Ccp
0 0 0 0 0 -4 -0.20 0.012 -0.043
1.25 3.32 -0.86 1.23 4.18 -2 -0.05 0.0078 -0.007
2.5 4.36 -1.11 1.625 5.47 0 0.10 0.0085 0.030 0.300
5 5.69 -1.50 2.095 7.19 2 0.26 0.0128 0.067 0.257
7.5 6.48 -1.91 2.29 8.39 4 0.40 0.018 0.100 0.250
10 6.99 -2.38 2.31 9.37 6 0.55 0.027 0.137 0.249
15 7.53 -3.18 2.18 10.71 8 0.70 0.038 0.173 0.247
20 7.80 -3.68 2.06 11.48 10 0.85 0.052 0.208 0.245
25 7.87 -4.00 1.94 11.87 12 1.00 0.070 0.249 0.244
30 7.81 -4.20 1.81 12.01 14 1.16 0.090 0.283 0.244
40 7.35 -4.26 1.55 11.61 16 1.30 0.112 0.318 0.244
50 6.59 -4.00 1.30 10.59 18 1.41 0.136 0.346 0.245
60 5.60 -3.51 1.05 9.11 20 1.54 0.161 0.378 0.245
70 4.46 -2.88 0.79 7.34 21.8 1.62 0.185 0.397 0.245
80 3.15 -2.10 0.53 5.25 21.8 1.26 0.266 0.370 0.302
90 1.71 -1.19 0.26 2.90 24 1.11 0.334 0.386 0.348
95 0.93 -0.69 0.12 1.62 28 1.00 0.379 0.379
100 0 0 0 0 30 1.97 0.392 0.404
-
7/23/2019 Calculation of Wing Loads
46/55
46
The airfoil NACA-24012
Geometric characteristic of airfoil (in
% from chord)
Aerodynamic characteristic of airfoil
X Yt Yb Ym h Cy Cx Cm Ccp
0 0 0 0 0 -4 -0.20 0.012 -0.035
1.25 2.58 -1.34 0.62 3.92 -2 -0.04 0.0075 -0.0035
2.5 3.50 -1.85 0.83 5.35 0 0.11 0.008 0.0391 0.356
5 4.80 -2.37 1.22 7.172 0.28 0.013 0.079 0.282
7.5 5.74 -2.70 1.52 8.44 4 0.42 0.019 0.125 0.298
10 6.44 -2.95 1.75 9.39 6 0.57 0.027 0.148 0.259
15 7.37 -3.34 2.015 10.71 8 0.71 0.040 0.1815 0.255
20 7.82 -3.66 2.08 11.48 10 0.86 0.054 0.217 0.252
25 7.96 -3.92 2.02 11.88 12 1.01 0.072 0.252 0.250
30 7.89 -4.11 1.89 12.00 14 1.16 0.092 0.287 0.247
40 7.44 -4.17 1.64 11.61 16 1.30 0.113 0.321 0.246
50 6.66 -3.93 1.40 10.59 18 1.43 0.140 0.352 0.247
60 5.67 -3.47 1.10 9.14 20.8 1.59 0.175 0.390 0.245
70 4.48 -2.84 0.82 7.32 21.5 1.60 0.190 0.392 0.245
80 3.18 -2.07 0.56 5.25 21.5 1.38 0.235 0.387 0.280
90 1.73 -1.18 0.28 2.91 24 1.30 0.315 0.388 0.299
95 0.94 -0.67 0.14 1.61 26 1.18 0.368 0.400 0.339
100 0 0 0 0 30 1.00 0.461 0.387 0.387
-
7/23/2019 Calculation of Wing Loads
47/55
47
The airfoil CLARK-YH
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic of airfoil
X Yt Yb h Cy
Ccp
0 0 0 0 --16 -0.596 0.203 0.356
2.5 3.10 -2.03 5.13 -12 -0.562 0.095 0.264
5 4.59 -2.54 7.13 -8 -0.388 0.025 0.196
7.5 5.62 -2.81 8.43 -4 -0.130 0.013 -
10 6.42 -3.03 9.45 -2 0.000 0.012 -
15 7.57 -3.24 10.81 0 0.130 0.013 0.493
20 8.33 -3.25 11.58 2 0.266 0.023 0.330
30 8.85 -3.14 11.99 4 0.400 0.072 0.278
40 8.66 -3.00 11.66 8 0.656 0.043 0.308
50 7.91 -2.84 10.75 10 0.792 0.059 0.300
60 6.71 -2.69 9.40 12 0.924 0.077 0.294
70 5.07 -2.43 7.50 16 1.166 0.118 0.286
80 3.39 -1.98 5.37 18 1.258 0.146 0.286
90 1.73 -1.21 2.94 20 1.28 0.180 0.297
95 0.90 -0.69 1.59 22 1.24 0.239 0.316
100 0.08 -0.08 0.16 24 1.148 0.289 0.344
-
7/23/2019 Calculation of Wing Loads
48/55
48
The airfoil CAGI 6-8.3%
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic of airfoil
X Yt Yb h Cy
Ccp
0 0 0 0 -2 0.034 0.0110
2.5 1.80 -0.98 2.78 0 0.168 0.012 0.619
5 2.78 -1.23 4.01 2 0.294 0.016 0.470
7.5 3.62 -1.32 4.94 4 0.428 0.022 0.298
10 4.29 -1.34 5.63 6 0.562 0.032 0.359
15 5.26 -1.34 6.60 8 0.684 0.045 0.342
20 6.05 -1.28 7.33 10 0.808 0.061 0.322
30 7.20 -1.09 8.29 12 0.922 0.067 0.303
40 7.04 -0.90 7.94 14 1.004 0.122 0.298
50 6.63 -0.60 7.23 16 1.038 0.168 0.308
60 5.82 -0.35 6.17 18 1.024 0.231 0.346
70 4.52 -0.28 4.80
80 3.04 -0.16 3.20
90 1.51 -0.07 1.58
100 0 0 0
-
7/23/2019 Calculation of Wing Loads
49/55
49
The airfoil MUNK- 1
Geometric characteristic of airfoil(in %from chord)
Aerodynamic characteristic of airfoil
X Yt Yb h Cy
Ccp
0 0 0 0 --3 -0.208 0.009 ----
2.5 1.36 -1.36 2.72 1.5 -0.104 0.008 ---
5 1.8 -1.8 3.6 0 -0.006 0.007 ---
7.5 2.1 -2.1 4.2 1.5 0.120 0.008 0.158
10 2.34 -2.34 4.68 3 0.231 0.011 0.198
15 2.67 -2.67 5.34 4.5 0.341 0.014 0.237
20 2.88 -2.88 5.76 6 0.458 0.020 0.240
30 3.05 -3.05 6.1 9 0.667 0.034 0.264
40 2.85 -2.85 5.7 12 0.782 0.101 0.275
50 2.53 -2.53 5.06 15 0.805 0.196 0.2286
60 2.08 -2.08 4.16 18 0.788 0.257 0.312
70 1.54 -1.54 3.08 21 0.742 0.297 ---
80 0.91 -0.91 1.82
90 0.20 -0.20 0.40
100 0 0 0
-
7/23/2019 Calculation of Wing Loads
50/55
50
Appendix 2THE STANDARD ATMOSPHERE IN SYSTEM SI.
Height.
,m
Temperature
tH,0C
Pressure
PH,Pa
Density
,kg/m3
Relative
density,=/0
Acoustic
speedm/s km/h
-1000 21.5 113920 1.347 1.099 344.1 1238
0 15 101325 1.225 1.000 340.2 1225
1000 8.5 89860 1.11 0.907 336.4 1211
2000 2.0 79500 1.006 0.821 332.5 1197
3000 -4.5 70130 0.909 0.742 328.5 1183
4000 -11.0 61595 0.819 0.668 324.5 11685000 -17.5 54000 0.736 0.601 320.5 1154
6000 -24.0 47200 0.660 0.539 316.4 1139
7000 -30.5 41060 0.590 0.482 312.2 1124
8000 -37.0 35600 0.526 0.420 308 1109
9000 -43.5 30800 0.467 0.381 303.8 1093
10000 -50.0 26400 0.413 0.337 299.4 1078
11000 -56.5 22665 0.365 0.298 295 1062
12000 -56.5 19385 0.312 0.254 295 1062
13000 -56.5 16570 0.266 0.217 295 1062
14000 -56.5 14160 0.228 0.186 295 1062
16000 -56.5 10280 0.166 0.137 295 1062
18000 -56.5 7560 0.120 0.099 295 1062
20000 -56.5 5520 0.088 0.072 295 1062
-
7/23/2019 Calculation of Wing Loads
51/55
51
Appendix 3RELATIVE CIRCULATION BY WINGSPAN STRAIGHT TRAPEZOIDAL
CENTER-SECTION-LESS FLAT WING
f(5
10)=2z/l = 1 = 2 = 3 = 4 = 5
0.0 1.1225 1.2721 1.3435 1.3859 1.4157
0.1 1.1261 1.2624 1.3298 1.3701 1.3987
0.2 1.1196 1.2363 1.2908 1.3245 1.3490
0.3 1.1096 1.1890 1.2228 1.2524 1.2711
0.4 1.0961 1.1299 1.1484 1.1601 1.1703
0.5 1.0765 1.0590 1.0570 1.0543 1.0561
0.6 1.0457 0.9814 0.9571 0.9419 0.9343
0.7 0.9954 0.8988 0.8538 0.8271 0.8098
0.8 0.9138 0.8032 0.7430 0.7051 0.6784
0.9 0.7597 0.6513 0.6090 0.5434 0.5115
0.95 0.6599 0.5151 0.4593 0.4092 0.3798
1 0 0 0 0 0
Comment.
1. Wing has not center-section (2 lc= 0).2. Wing is flat.
3. Wing aspect ratio is equal to wSwL2
.
4. Wing taper is equal to tb/b0 .
5. For low-wing monoplane f is given from board rib, for mid-wing and high-wing fis given from axial rib.
6. If wing taper
differentiates from table data then valises f are calculated by linearinterpolation.
-
7/23/2019 Calculation of Wing Loads
52/55
52
Appendix 4
THE
(45)AMENDMENT FOR WING SWEEP ON THE CHORDS FOURTHWHICH IS EQUAL 45.
2z/l
s(45) 2z/l
s(45)0 -0.235 0.6 0.0730.1 -0.175 0.7 0.111
0.2 -0.123 0.8 0.135
0.3 -0.072 0.9 0.140
0.4 -0.025 0.95 0.125
0.5 0.025 1.00 0
-
7/23/2019 Calculation of Wing Loads
53/55
53
Appendix 5MINISTRY OF EDUCATION AND SCIENCE OF UKRAINE
National Aerospace UniversityKharkiv Aviation Institute
Strength Department
CALCULATION OF WING LOADS
Explanatory book
(ALL THE WAY-0000-0000LEB)
Fulfilled by:
Checked up by:
Kharkiv 2015
-
7/23/2019 Calculation of Wing Loads
54/55
54
REFERENCES
1. . . . . . 1985.
2. . . . . . 1992.
3. . .. . . . . 1978.
-
7/23/2019 Calculation of Wing Loads
55/55
CONTENTS
INTRODUCTION....31. AIRPLAIN GENERAL DATA41. 1. WINGS GENERAL DATA51.2. WINGS GEOMETRICAL DATA..52. DETERMINATION OF LIMIT LOAD FACTOR...103. WINGS MASS DATA 104. WINGS LOADS CALCULATION ....134.1. AIR LOADS ALLOCATION BY THE WINGS SPAN. 164.2. THE WING STRUCTURE MASS LOAD ALLOCATION....174.3. CALCULATION OF THE TOTAL DISTRIBUTED LOAD ON A WING.174.4. THE CHEAR FORCES. BENDING AND REDUCED MOMENTS DIAGRAMSPLOTTING18
4.5. LOAD CHECKING FOR WING ROOT CROSS SECTION254.6. CALCULATION OF SHEAR FORCES POSITION IN THE DESIGN CROSSSECTION...25
APPENDIXIES..27APPENDIX 1.CHARACTERISTIC OF AIRFOIL..28APPENDIX 2. THE STANDARD ATMOSPHERE IN SYSTEM SI .......50APPENDIX 3. RELATIVE CIRCULATION BY WINGSPAN51
APPENDIX 4. THE
(45)AMENDMENT FOR WING SWEEP 52APPENDIX 5. THE COVER PAGE ....53
REFERENCES54