Introduccion Estructuras Aeronauticas 2016-1

8/18/2019 Introduccion Estructuras Aeronauticas 2016-1

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ESTRUCTURAS AERONAUTICAS

Introducción

Ing. Fabio Merchán, CMSc, Esp.


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• The primary factors to consider in aircraft structures are

strength, weight, and reliability.

All materials used to construct an

aircraft must be reliable.

Reliability minimizes the possibility of

dangerous and unexpected failures.

http://www.zenithair.com/zodiac/gif/6fox2.jpg


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Forces

A/C

Structural

stressesConditions

Flying Statics

Force of gravity produces weight

Landing gear

Absorbs the forces

Maneuver

Causes acceleration or deceleration

increases the forces and stresses on the

wings and fuselage.

Aircraft structural

members are

designed to carry a

load or to resist

stress.


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CargasExternas

CargasInternas

Esfuerzos

Deformaciones


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Tipos de cargas y esfuerzos

• Limit Loads: are Maximum loads expected during service.

• Stress is defined like a applied load per area of the material.

Taking into account that the

principal stresses on the

fuselage and wings are

transmitted for each

component to the principal

structures.


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Tensión, es una fuerza

actuando en contra de

otra fuerza que esta

tratando de jalar algoaparte.

Compresión, se

considera como unafuerza que intenta

hacer las parte mas

pequeñas.

Torsión se considera

como una fuerza que

tiende a torcer una

parte.

Combinación de dos

fuerzas, compresión y

tensión.

Esfuerzo cortante, se

considera cuando

una pieza de material

se deliza sobre otra.


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These stresses are absorbed by each component of the

wing structure and transmitted to the fuselage structure.


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Bending force on the fuselage Bending action creates a tensionstress on the lower skin of the

fuselage and a compression stress on

the top skin. Airflow


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What happen in the flight?

Lift forces act upward againstthe wings.

Bend them upward

The wings are prevented from

folding over the fuselage by the

resisting strength of the wingstructure.


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Thrust is the power which

enables an airplane to move

forward (engine). Lift is the force

aroused by thrust.

Wing

Lift airfoil

Propeller

Thrust airfoil


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RECUENTO HISTORICO Y

MATERIALES

• Primeros aviones: Madera de bambú ysuperficies en “fabric” (1910).

• Estructuras tipo “TRUSS”.• Estructuras livianas y de difícil acabado

aerodinámico por la técnica de construcción.

• Nuevos registros de velocidad y exigencias decarga generan cambio materiales por maderaprensada “PLYWOOD” (1920).


12/111http://plymaster.com.au/pics/CD%20grade%20Plywood%20[Desktop%20Resolution].jpg

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• Irish linen and cotton.

Covering airframes. Sag

aircraft structure.

• Builders began coating the

fabrics with oils and

varnishes.

• Extreme flammability.

• Lack of durability, limitedservice life.

• Coated fabric proved

unsuccessful.http://cherokeesailplanes.blogspot.com/2010_03_01_archive.html

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An edge which has been cut by machine or special pinking shears

Materials and techniques are in the

manufacturer’s service manual.

Aircraft originally manufacturedwith cotton fabric can only be re-

covered with cotton fabric unless

the Federal Aviation

Administration (FAA) approves an

exception.

Approved supplemental type

certificate (STC).

Field approval


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• Do the work in accordance with

an approved supplemental type

certificate (STC).

• Specify that it is for the

particular a/c model inquestion

Detail exactly what alternate

materials must be used and what

procedure(s) must be followed.

STC


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STC

Alteraciones o modificaciones principales a un

producto aeronáutico.

Estructura

Resistencia estructural

Cambios es peso y balance

Componentes o sistemas

Limitaciones de operación

Aeronavegabilidad del producto

Cambian las condiciones del Certificado Tipo


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Alteración mayor o menor

Mayor Menor

Se tienen

suficientes datos

aprobados

No requiere

aprobación decampo

No requiere de

un aprobaciónde campo

Requiere una

aprobación decampo

SI NO


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• A Field Approval is the granting, by an

FAA airworthiness inspector, of FAA

“approval” for a major repair or major

alteration. The approval is given only after conducting a physical inspection and/or

after reviewing data.


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OVERVIEW OF THE STEPS

• Do your homework.

• Create a standard data (SDP) package as

described in the ac.• Submit the SDP to the local FSDO (Flight

Standards district office) .

• Interact with the ASI (aviation safetyinspector).

• Receive a final response.


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WHAT WILL THE ASI DO

• Evaluate the data.

• And if necessary

– Request additional data – Forward to another ASI.

– Request engineering help (ACO) FAA AircraftCertification Office.

• Or Approve the data, or Deny therequest—in writing


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D t ió té i


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Documentación técnica

para definir y sustentar

alteración o reparación

Información de diseño y

cálculos de Ingeniería

Orden de Ingeniería

Planos

Diseño de pruebasEspecificaciones

técnicas

Análisis de peso y balance

Limitaciones

operacionales

Características de vuelo

Propuesta de suplementos a los manuales,

dimensiones, materiales y procesos.


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Hojas de datos técnicos del certificado

tipo (TCDS)

Datos del certificado tipo

suplementario. (STC) previniendo que

este aplica específicamente al

elemento que esta siendo

reparado/alterado. Tal documento

puede ser considerado en su totalidad

o en parte como incluido dentro de los

datos de diseño asociados con el STC

Directivas de aeronavegabilidad

(AD’s)

Manuales de Mantenimiento o

instrucciones del fabricante aprobadas

por la Autoridad Aeronáutica del

Estado de Certificación del Producto.

Porciones del SRM aprobadas por la

Autoridad Aeronáutica del Estado de

Certificación del Producto. Manual de

reparaciones estructurales (SRM),

solamente como una fuente de datos

técnicos aprobados para una

reparación mayor cuando es un

documento aprobado por una autoridadaeronáutica.


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Que diferencias hay entre reparaciones y

alteraciones mayores???

Es cuando retorna laaeronave o

componente a su

diseño Tipo original.

Es un cambio deldiseño tipo original de

la aeronave o

componente.

Alteración

mayor

Reparación

mayor


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Actividad extraclase

“Alteraciones mayores”

• Es una modificación registrada en las especificaciones

de la a/c?.

• Afecta o no la aeronavegabilidad de la a/c? En que

aspectos.• Se puede hacer por medio de operaciones elementales

de manto?

• Como se da el manejo de alteraciones mayores en

Colombia?• Que tipo de alteraciones y reparaciones mayores son

permitidas según el RAC


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BELL TEXTRON HELICOPTER Inc Kit Huey II

Componentes para la conversión

Cambio de rotor de cola y palas a modelo Bell

212.

Cambio de rotor principal y palas a modelo

Bell 212,

Kit para conversión de la transmisión principal

a modelo Bell 212,

Cambio de mástil, platillo oscilante y controles

a modelo Bell 212,

Cambio de cono de cola con todoscomponentes a modelo Bell 212,

Cambio de cajas de engranaje de 42 y 90

grados a modelo Bell 212,

Cambio de ejes impulsores y colgantes de rotor

de cola a modelo Bell 212,


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WHAT ARE THE REASONS FOR DENIAL

• Minor alteration—no 337 needed.

• Major change—STC needed.

• Data is already approved—no further approval isneeded

• Alteration contrary to safety.

• Continued failure to provide an adequate SDP—

FAA terminates the project.


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WHAT IS IN THE SDP

1. Field Approval Checklist.

2. Copies of supporting data including

any previously approved data.

3. FAA Form 337 not signed in block 6

or 7.


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DATA

• Chapter 2 of the AC provides all you need to

know about substantiating data.

• Approved data.

• Acceptable data.

• DER (Designated Engineering Representative)

approval of data.

• DER limitations.


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THE FIELD APPROVAL PROCESS

• Research.

• Obtain field approval.

• Perform the alteration.


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RESEARCH

• Thoroughly understand what is involved in

the alteration and how the aircraft and its

other systems will be affected by the workyou plan to do.

• Thoroughly understand how the approved

operation(s) of the aircraft be affected


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RESEARCH

• AIRCRAFT TECHNICAL REQUIREMENTS

– Previous Alterations

– A/C Manufacturer’s Data – Service Bulletins

– STC’s already approved

– Other Field Approvals

– Flight Manual Supplements


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RESEARCH

• Equipment manufacturer’s technical

data

– Installation manuals

– STC’s

– Other data


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FAR 23

23.301 loads

Strength requirements arespecified in terms of limit

loads (the maximum loadsto be expected in service)and ultimate loads (limit

loads multiplied byprescribed factors of safety)

The air, ground, and waterloads must be placed inequilibrium with inertia

forces, considering each

item of mass in the airplane

23.305 Strength anddeformation

The structure must be ableto support limit loads without

detrimental, permanentdeformation. At any load up

to limit loads, the

deformation may notinterfere with safe operation.


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FAR 23 Flight loads

23.321 General

Flight load factors

represent the ratio of theaerodynamic force

component

23.331 Symmetricalflight conditions

The wing loads and linearinertia loads

corresponding to any ofthe symmetrical flight

conditions

The incrementalhorizontal tail loads due

to maneuvering andgusts

23.333 Flight envelope

The airplane is assumedto be subjected to

symmetrical verticalgusts in level flight

Combination of airspeedand load factor

GROUND LOADS


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GROUND LOADS

External loads and inertia forces that

act upon an airplane structure

23.479 Level landingconditions

23.481 Tail down landingconditions

23.483 One-wheel

landing conditions.

23.485 Side load conditions.

23.493 Braked roll conditions

3.507 Jacking loads. 23.509 Towing loads.


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• PLYWOOD is replaced for aluminum

laminates.

• Duraluminum is discovered in Germany

(1909 – Alfred Wilm – Durener Mettalwerke).

• Wood limitations due to production crisis

1914-1918 and the change in the elasticproperties due to environment.


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• Germany 1915-1919 Junkers J.L.6

(iron/steel)


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• DeHavilland “MOSQUITO” 100% wood

incorporate adhesive technology (thermoset

resin and thermoplastic resin)


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• Due to the new characteristics of

performance and new complexstructures the use of wood is just.

• Wing load more high and concentrationstress on critic points of the structures

like WING BOX and MLG TRUNNIONS,

where the wood wasn´t good adapted.


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ALEACIONES DE ALUMINIO

• Usadas extensivamente en estructuras, pieles y

otros miembros estructurales sujetos a cargas.

• Sistema 4 dígitos de identificación de la aleaciónde aviación.


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GRUPO TIPO ALEACION

1XXX Aluminio 100% puro

2XXX Aleación de Cu

3XXX Aleación de Mn

4XXX Aleación de Si

5XXX Aleación de Mg

6XXX Aleación Mg + Mn7XXX Aleación de Zn

Código de cuatro dígitos : 1 2 3 4

1: Tipo de aleación

2: Modificación de la aleación

3-4: Pureza de aluminio


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ALEACIONES DE AVIACION

1100, Aluminio puro, uso no estructurales

2024, La más usada, tratable térmicamente

3003, Similar 1100, no tratable, endurecida por

trabajo en frio.

5052, Para aplicaciones compatibles con procesos de

soldadura, no tratable térmicamente.

6061, Aleaciones de media resistencia y buen

formado con tratamiento térmico, soldables.

7075, La de mejor resistencia, usos estructurales

primarios, tratable térmicamente.


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HIDUMINIUM RR58 (Concorde), aleación de Cu, Mg,Ni, Fe (1939-1945), alta resistencia temperatura.

%Cu %Mg %Si %Fe %Ni %Ti %AlMin2.25 1.35 0.18 0.90 1.0 - Resto

Max2.70 1.65 0.25 1.20 1.30 0.20

Condiciones F, T, H, O


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• Aleaciones de Mg, más livianas, más

reactivas (corrosión), frágiles.

• Aleaciones de Ti, Similar relación

resistencia/peso a las aleaciones de Al,

uso extendido aviación militar (Wingbox

F14/F15/F22).



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• Aleaciones de Acero, Alta resistencia, bajo

contenido C (0.03%), gama de inoxidables

con alta resistencia a la temperatura (X-15

pieles de cromo-niquel).


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OTROS MATERIALES

• Plásticos acrílicos (familia resinas termoplásticas).PLEXIGLAS/LUCITE/PERSPEX.

• Compuestos, Resistencia mayor a las aleaciones de Al,significan entre 15%-20% peso estructural (comercial), aviación

militar uso extendido.

• GFRP (glass-fiber reinforced plastic) ,AFRP (Aramid Fiber Reinforced Polymer), CFRP (Carbon-fiber-reinforcedpolymer) (Fibras de vidrio, aramidas-kevlar, Carbon/Grafito-Boro).

• Altos costos producción/mantto.

• Economía en carga paga y combustible


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ESTRUCTURAS AERONAUTICAS

OBJETIVO

• Resistir y transmitir las cargas,

proporcionar formasaerodinámicas y proteger

pasajeros/carga/sistemas del

avión de las condiciones

ambientales encontradas

durante el vuelo.


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• Primary structure: Structural elements that in

case of damage or failure could lead to failure of

the entire craft.

– Primary structure is that structure which carries flight,

ground, or pressurization loads, and whose failure

would reduce the structural integrity of the airplane.

• Secondary structure Structural elements that arenot part of the primary structure. Structural

elements mainly to provide enhancedaerodynamics.


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TIPOS DE ESTRUCTURAS

• Estructura de piel esforzada (Stressed skin

structure).

• La gran parte de los esfuerzos son soportados

por la piel exterior.

• Poca cantidad de miembros estructurales

internos.

• Buena capacidad para dar formasaerodinámicas.

• Alta probabilidad de grietas por efectos de

ondulamiento o “buckling”.


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Semimonocasco:

Conjunto de formadores,

larguerillos, y mamparos

unidos entre si a loscuales se adhiere la piel.

Monocasco: Conjunto de

formadores y mamparos

unidos a la piel quiénsoporta las cargas de

operación.

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• Although very strong, monocoque construction is

not highly tolerant to deformation of the surface.

• The biggest problem in monocoque construction ismaintaining enough strength while keeping the

weight within limits.

The formers and bulkheads

provide shape for the

fuselage.

The skin carries the primary

stresses.

No bracing members are

present.

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• Conclusion

– Unstiffened shells. must be

relatively thick to resist bending,compressive, and torsional loads.


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• Conclusion

– Constructions with stiffening members that

may also be required to diffuse concentrated

loads into the cover. – More efficient type of construction that permits

much thinner covering shell.



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• Truss type: Formada por largueros

soldados entre si que forman “well-

braced framework”.

• Miembros verticales y horizontales

(struts) dan forma rectangular o

cuadrada.

• Se instalan “struts” adicionales para

soportar esfuerzos. Larguerillos,mamparos y formadores se añaden

para dar forma al fuselaje e instalar la

piel.


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TERMINOLOGIA ESTRUCTURAS


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• Frame (Formador)

Es un miembro

circunferencial usado enla construcción semi-

monocasco que soporta

los larguerillos y la piel.

Los formadores están diseñados para soportar cargas

laterales y los momentos de flexión adicional a las cargas

axiales.

Son vigas

circulares en

J o C.


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Give cross-sectional shape toFormers are the lightest.

h d i il f


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Give cross-sectional shape to

the fuselage, and they add

ridigity and strength to the

stucture.

The are used primarily for

fillings or skin attachments

between the larger members.

Frame assemblies are used toseparate one section of the

fuselage from another.

BULKHEADS

Heavier than formers,

they are equipped

with doors or other mens of access.

Struc tu re termino logy


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gy

• Longerons (Largueros)

• The strong, heavylongerons hold the

bulkheads and formers.

• The bulkheads andformers hold the stringers.

• Rigid fuselage framework.

Generally the 20 to 40 stringers are replaced by 4 to 6 longerons. Longerons as the

stringers resists the bending load of the fuselage.

Primary bending loads are

taken by the longerons,

which usually extend across

several points of support.

Función de largueros/largueri l los


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.

They have the same job and application than the stringers,

but longerons are stiffer beams, mainly machined and they

are in less number over the circular periphery of the

fuselage circle.

Axial

Load

Stringers and longerons prevent tension and compression stresses from

bending the fuselage.

Designed

Support the axial forces

nevertheless

Support lateral forces Flexion moment



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• Stringers (Larguerillos)

They are longitudinal beams in

C, L or T form located in thecircular periphery of the

fuselage and equally circular

spaced over the fuselage

diameter.

The fuselage skin thickness varies with the load carried and

the stresses sustained at particular location.


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TIPOS DE “STRINGERS”

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The main job is to retain the bending loads

applied to the fuselage.

They are riveted attached to skins

and frames. To skins to increasestiffness, to frames to increase

buckling resistance.



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• Beams (Vigas)

Es un miembro primario

de un formador o un alausado para soportar

grandes cargas incluyendo

momentos de flexión.

En las alas es a menudollamado como “spar”.



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TIPOS DE “BEAMS”

.

Función de las vigas


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Las vigas estandiseñadas para

soportar cargas

laterales y los

momentos de flexión

que usualmente son

mayores comparados

con sus respectivascargas axiales

• Las cargas laterales serefieren a los esfuerzos

cortantes (Shear

Stresses).

• Los momentos deflexión causanesfuerzos decompresión y tensión

Función de las vigas


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.

Están diseñados para soportar cargas axiales (tensión

y compresión) aplicadas en sus extremos

unicamente.

Función estructuras “truss”


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Las vigas que deben

soportar grandes cargas

axiales, particularmente

cargas de compresión, en

conjunto con cargas

laterales y momentos de

flexión son llamadas vigas

de columna o beam-columns.


Nose section Center section Aft or rear section


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Centre section needs to be large and strong. Why?

Windows and doors


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Cut-outs

When we design anaircraft it’s very important

and necessary

It’s a engineering structural

problem

The fuselage needs to be strengthened around

them.

The loads must be routed around

the cut-outs.

Spread evenly into surrounding skin and structure.

Wings


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g

• The wing is the aircraft structural part that generate the

require lift force that permits the aircraft to fly.

• Use the wing to transport fuel, engines, pylons and

external fuel tanks.

Wings structure must

resist several kind of

different loads appliedto it:

vibration loads

lift load

drag load

engine thrust load

main landing gear loads

SPAR

In its simplest form, the wing is a

framework made up of spars and

ribs and covered with metal


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All the load carried by the wing

is taken up by the spars.

Designed to have great

bending strength.

Transmit the air load from the

wing covering to the spars.

SPAR

RIBS

ribs and covered with metal.

• Spar : The main center beam of the wing, designed to carry the


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structural loads and transfer them by attachment to the fuselage, or

body, of the aircraft.

• Root: The wing root is the portion of the wing that attaches to thefuselage, or body of the aircraft.

• Skin: The outer surface of the wing. Originally made of fabric,

modern aircraft use aluminum or composite materials due to their

lightweight and rust-resistant properties.

• Ribs & Stringers: These make up the inner skeleton of the wing,

providing rigidity and strength. While strength is necessary, it is also

important that the wing can flex slightly while it flies. This flexibility

allows it to absorb the stress caused by turbulence and hard

landings.

Zodiac wing.

Zodiac wing assembly.

Zodiac wing skin.

http://localhost/var/www/apps/conversion/tmp/Docs%20apoyo/zodiac%20wing.pdfhttp://localhost/var/www/apps/conversion/tmp/Docs%20apoyo/zodiac%20wing%20assembly.pdfhttp://localhost/var/www/apps/conversion/tmp/Docs%20apoyo/zodiac%20wing%20skin.pdfhttp://localhost/var/www/apps/conversion/tmp/Docs%20apoyo/zodiac%20wing%20skin.pdfhttp://localhost/var/www/apps/conversion/tmp/Docs%20apoyo/zodiac%20wing%20assembly.pdfhttp://localhost/var/www/apps/conversion/tmp/Docs%20apoyo/zodiac%20wing.pdf


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http://www.zenithair.com/bldr/images/6wing/hds%20top%20skin.jpg

http://www.zenithair.com/bldr/images/6wing/hd%20wing%20skeleton.jpg

https://reader009.{domain}/reader009/html5/0727/5b5affac8cde3/5b5affd477f6e.jpg

Air loads increase as a the square of

the speed increase.For instance at 500 knots the air loads

are five times.

• The front spar is located at about 15 % chord.

• The rear spar at 55 to 60%.


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p

Typical spar sections Wing strong.

Very high speed aircraft.

May resist thebending forces

imposed on it.

• Monospar wing


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http://www.langleyflyingschool.com/Pages/CPGS%203%20Airframes,%20Engines%20and%20Systems,%20Part%201.html

Wing skin


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The two main spars are still

the main strength members,

but a large contribution to the

strength is made by the skin.

stressed-skin design

Skin share some of the load.

Web of a spar may be a plate or a

t


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truss.

Light weight materials with vertical stiffeners

employed for strength.

Fail-safe spar web design

Member of a complex structure fail

Other part of the structure

assumes the load of the

failed member and permits

continued operation.


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• According to the AC 23-13A, define Fail-safe:

– Fail-safe is the attribute of the structure that

permits it to retain its required residual

strength for a period of unrepaired use after

the failure or partial failure of a principalstructural element.

The structural load must be transferred by two loading paths,


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y g p ,

if one of the loading paths fails the other must be capable to

safely transfer all the load with no structural failure.

Aeroteaching blog handbook


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What is a Principal Structural Element?

• A principal structural element (PSE) is an element that

contributes significantly to carrying flight, ground, or

cabin pressurization loads, and whose integrity isessential in maintaining the overall structural integrity of

the airplane.

Fixed surface,

t bil t t i bl

Integrally stiffened

plates


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PSEs

Wing

vertical fin

canard

winglets/tipfins

forwardwing

horizontalstabilizer

stabilator, or trimmable

stabilizer attachment

fittings.

plates

Primary fittings

Principal splices

Skin or reinforcement

around cutouts or

discontinuitiesSkin-stringer combinations

Spar caps

Ci f ti l


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Pressurizedcabin

Circumferentialframes and

adjacent skin

Pressurebulkheads

Window frames

Skin around acutout

Door frames,skins, andlatches;

Skin and anysingle frame or

stiffenerelement around

a cutout

Cockpit window

The center wing is made bya structure assembly called

the wing box

The center wing is integrated with the

fuselage structure.


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the wing box.g

Main structural resistance of the wing to all type of loads applied to it.

All this elements are generally

made of machined high strength

aluminium alloys or titanium

alloys because of the high

strength requirements.

The center wing interior is mainly

used as fuel tank compartment

and main landing gear

compartment.

What kinds of d f i i l di


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loads resist the

wing box?

Loads of engines, main landing

gear loads, external tanks, drag, lift

and inertial loads.

The outer wing is bolted to the root rib of the center

wing in order to transfer all the loads to the structure.

REMENBER

• Wing tip


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– Non critical structures.

– Reduce drag and increase lift.

Box beam or torsion box construction

Main spars Stressed skin

Lighter construction (composites)

Wet wing

EFECTOS EN LA ESTRUCTURA


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1. Igual función, diferente estructura.

– DHC-6 (Twin Otter) configuración simple dosvigas y costillas.

– Avión militar, múltiples vigas y pocas costillas ylarguerillos.

2. Las costillas dan forma al perfil, actúa con la pielresistiendo cargas de presión aerodinámicas.

3. Distribuyen cargas concentradas y re-distribuyenesfuerzos alrededor de discontinuidades.

4. Incrementan la resistencia a la deformación por “doblamiento” o “buckling stress”.



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5. Las costillas cambian de tamaño según forma del ala

(rectangular, elíptica, tappered, etc), su posición y las cargas

soportadas.

6. Puntos intermedios, soportan reacciones superficies de

control.

7. Los paneles de piel forman una superficie impermeable para

soportar la distribución de presión aerodinámica, y las cargas

son transmitidas a costillas y larguerillos.



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8. Estructura de celda, la resistencia al corte y torsiónes proporcionada por esfuerzos de corte

desarrollados en la piel y el alma de las vigas.

9. Cargas axiales y flexión son soportadas por laacción combinada de la piel y los larguerillos.

10. Larguerillos unidos a la piel y estos a su vez a las

costillas le dan rigidez al conjunto.



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11. Fuselajes, miembros con funciones similares,

origen y cargas soportadas diferentes.

12. Reacciones de superficies, cargas puntuales

(MLG), carga paga implican fuerzas de inercia.

13. Cargas de presurización radiales y repetitivas.

14. Estructuras ideales, secciones redondas o con sub-

secciones similares.

15. Aviones no presurizados tienen formas cercanas al

cuadrado o rectángulo.



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16. Fuselaje, construcción simple en celda tubular dedelgada piel, formadores transversales, larguerillos

y otros miembros estructurales que se extienden a

través del fuselaje en secciones específicas

llamados mamparos o “Bulckheads”.

17. Formadores, soportan cargas concentradas del piso

o provenientes del ala, puntos de sujeción de

superficies. Más robustos que otros ligeramente

cargados y de formas que proporcionen rigidez y

transmisión de cargas a otro formadores y la piel.

Flight control surfaces


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Change the attitude of the aircraft during flight.

Primary Secondary Auxiliary

Ailerons, elevators,

and rudders

Longitudinal

control axis

(lateral stability)

Lateral control

axis (longitudinal

stability)

Vertical control axis

(directional stability)

Trim tabs, spring tabs.

Let the pilot trim out an

unbalanced condition without

exerting pressure on the

primary controls.

Aid the pilot in moving a

larger control surface, such as

the ailerons and elevators

Wing flaps, spoilers,

speed brakes, and

slats.

Additional

control of theaircraft

Higher CLmax allows the aircraft to


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have a smaller wing area that

results in a lighter wing

Temporarily vary (increase) the

wing camber.

High lift device is deflected

downward

http://www.youtube.com/watch?v=EhMNpyOhSvU

http://www.youtube.com/watch?v=EhMNpyOhSvUhttp://www.youtube.com/watch?v=EhMNpyOhSvU


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Ejes de movimiento del Avión

• Pitch

http://localhost/var/www/apps/conversion/tmp/Documents/Ejecutables/Pitch/Pitchview.htmlhttp://localhost/var/www/apps/conversion/tmp/Documents/Ejecutables/Pitch/Pitchview.htmlhttp://localhost/var/www/apps/conversion/tmp/Documents/Ejecutables/Pitch/Pitchview.html


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• Roll

http://localhost/var/www/apps/conversion/tmp/Documents/Ejecutables/Roll/Rollview.htmlhttp://localhost/var/www/apps/conversion/tmp/Documents/Ejecutables/Roll/Rollview.html


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• Yaw

Dual Purpose Flight Control Surfaces

http://localhost/var/www/apps/conversion/tmp/Documents/Ejecutables/Yaw/Yawview.htmlhttp://localhost/var/www/apps/conversion/tmp/Documents/Ejecutables/Yaw/Yawview.html


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Elevons Perform the combined functions of theailerons and the elevator.

http://2.bp.blogspot.com/_mGkoANc7fi0/TRZSBR9M6kI/AAAAAAAAAnA/xJxPOV31Dzw/s1600/F117Banking2006.jpg

C bi th ti fRuddervator


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Combines the action of

the rudder and elevator

Flaperons are ailerons which can also act as

flaps.

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http://avstop.com/ac/Aviation_Maintenance_Technician_Handbook_General/images/fig3_67.jpg


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Tabs


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• Why is necessary use this kind of devices? Because………

1. The force of the air against a control surface during the highspeed of flight can make it difficult to move and hold that

control surface in the deflected position.

Stationary metal plate

Feet off of the controls and have the aircraft maintain


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its flight condition

Difficult to move a primary

control surface due to its surface


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area.

Speed of the air rushing over it.

Causes a force to position the

surface in the proper direction with

reduced force to do so.

Force to move the surfaces

Final stage of travel.

A control surface may require

excessive force to move

Balance tab

They aid the pilot in moving a

larger control surface, such as

the ailerons and elevators.

Causing air to strike the tab, in turn producing a force that aids inmaintaining the flight control surface in the desired position.

Flaps

Reduce the landing

Lowered increase


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• Give the aircraft

extra lift.

Reduce the landing

speed

Increasing the glide angle

without greatly increasingthe approach speed.

The flaps are lowered to increase the camber of the

wings and provide greater lift and control at slow

speeds.

Slats


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Slats are movable control surfaces

that attach to the leading edge of

the wing.

A slot is created between the slat

and the wing leading edge.

http://www.zenithair.com/stolch701/gif/

701-lift.jpg

The leading edge slats allow the

aircraft to fly at a high angle of

attack (lower speed).

Venturi effect that causes

accelerate de air between

the slot.

• This effectively "pulls" the air around the leading

d th ti th t ll t h


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edge, thus preventing the stall up to a much

higher angle of incidence and lift coefficient.

• Low airspeeds, this action improves the lateral

control handling characteristics.

Boundary layer

control air .

AileronsMove the aircraft about


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Move the aircraft about

the longitudinal axis.

Why amplifies the movement of the aircraft

around the longitudinal axis?

Camber is increased and lift is increased.

Destroy lift dependingof the roll requirement

for the aircraft.

Introduccion Estructuras Aeronauticas 2016-1

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