AIRCRAFT STRUCTURE

FAILURE PROJECT

Members:

Amirul Iman B. Hasri AD110155

Jaswant Singh Bal A/L Hadip Singh AD110177

Amal Iqmal B. Adnan AD110189

FACULTY OF MECHANICAL &

MANUFACTURING

ENGINEERING

AIRCRAFT STRUCTURES

BDU20103

http://www.dnv.com/binaries/PULS-buckling_tcm4-284864.JPG

VIDEO (INTRO)

News Of Aloha Airline 243 Disaster

WHO?

Captain Robert Schornstheimer

First officer Madeline "Mimi"

Tompkins

WHAT HAPPENED?

APRIL 28, 1988

At 13.25 P.M

A Boeing 737-200 operated by Aloha Airlines as flight 243 take off from Hilo and

its destination was to Honolulu, Hawaii. The first officer flew the plane while the

captain handle the radio communications with the air traffic control (A.T.C).

At 13.46 P.M

After just 21 minutes into the flight, , they experienced an explosive

decompression and structural failure at 24,000 feet. Part of the front of the

fuselage tare apart. First 5 rows were exposed completely to the sky.

Approximately 18 feet of the cabin skin and structure of the cabin entrance door

and above the passenger floor line separated from the airplane during flight.

Both pilots immediately take action:

Captain- control the plane & First officer- contact traffic control at Maui cause it

was listed as the alternate landing airport.

Continue…. At 13.50 P.M

The tower able to contact the pilots. So the pilots request an emergency

landing and equipment. They notice that the door at the fuselage is missing.

At 13.55 P.M

Captain request ‘ flight control manual inversion ’ ( used when hydraulic

system and power steering malfunction) by using the controlling yolk.

He puts the landing gear down and changes flap from 15 to 5 ( constantly

change the flaps to get the precise speed landing).

They safely land the aircraft at Kahului Airport on the Island of Maui.

There were 89 passengers and 6 crewmembers on board. One flight

attendant was swept overboard during the decompression and is presumed

to have been fatally injured. 7 passengers and 1 flight attendant received

serious injuries.

http://english4aviation.pbworks.com/w/page/24012381/Pressure

Pictures Aloha 243 Disaster

HOW?

The Boeing 737 was designed for safe decompression in which a small

hole acts as a valve to keep interior pressure from blowing the plane

apart. But boiler engineer Matt Austin says the design does not work if

something momentarily blocks the hole.

1. At 24000ft, forces exerted on the fuselage which had a crack along

rivet holes above the windows-open a 10-inch-square safe-

decompression hole in the roof.

2. Air from the pressurized cabin begins to rush out at about 700mph.

A flight attendant is sucked into, but not through, the opening. This

shuts off the rush of escaping air for a few ten-thousandths of a

second and pressure builds up to hundreds of pounds per square

inch-powerful enough to rib the plane apart. The side of the plane

blows out and downward, while the roof section peels up toward the

center. A section of the windows folds toward the rear, trapping the

flight attendant.

3. The window folds over, tearing back to a reinforced joint,

slamming against the fuselage. On the outside of the jet, blood and

a mark that Austin says is a skull print are found. Austin says that the

suggests the attendant’s body blocked the safe-decompression hole

instead of being immediately swept clear of the aircraft.

VIDEO (ACCIDENT)

AutoCAD Application

FINITE ELEMENT

ANALYSIS

ANSYS SOFTWARE

The Finite Element Method(FEM) is based on the

idea of building a complicated object with simple

blocks, or, dividing a complicated object into

small and manageable pieces. Application of

these simple idea can be found everywhere in

everyday life, as well as in engineering.

1943-Courant(Variational Methods)

1956-Turner,Clough,Martin, & Top(stiffness)

1960-Clough(FE, plane problem)

1970-Application on mainframe computer

1980-Microcomputers

1990-Analysis of large structural system

Design analysis-hand calculation, experiment,

and computer simulation

This is the most widely applied computer

simulation method in engineering.

Closely integrated with CAD/CAM applications

like AutoCAD.

One of several numerical methods that can be used to solve complex

problems and is the dominant method used today. As the name

implies, it takes a complex problem and breaks it down into a finite

number of simple problems.

A continuous structure theoretically has an infinite number of simple

problems, but finite element analysis approximates the behavior of a

continuous structure by analyzing a finite number of simple

problems.

Each element in a finite element analysis is one of these simple

problems. Each element in a finite element model will have a fixed

number of nodes that define the element boundaries to which loads

and boundary conditions can be applied.

The finer the mesh, the closer we can approximate the geometry of

the structure, the load application, as well as the stress and strain

gradients.

Example using finite element analysis

ANSYS offers a comprehensive range of engineering simulation

solution sets providing access to virtually any field of engineering

simulation that a design process requires. Companies in a wide

variety of industries use ANSYS software.

ANSYS is a finite element analysis (FEA) code widely used in the

computer-aided engineering (CAE) field.

ANSYS software allows engineers to construct computer models of

structures, machine components or systems which apply operating

loads and other design criteria and study physical responses, such as

stress levels, temperature distributions, pressure and others.

It permits an evaluation of a design without having to build and

destroy multiple prototypes in testing.

ANSYS(general purpose, PC & workstation)

NASTRAN(FEAnalysis on mainframe)

COSMOS(general purpose FEA)

ALGOR(PC & workstation)

SDRC/I-DEAS(Complete CAD/CAM/CAE package)

Examples using ANSYS software

Subject before being analyze

VIDEO (ANSYS)

Continue…

Subject after being applied with stress.

References

http://ntl.bts.gov/lib/38000/38500/38554/aloha_flight_243_a_new_direction.pdf

www.disastercity.com

Shari Stamford Krause, ‘Aircraft Safety Accident Investigations, Analyses & Applications’ Second Edition, McGraw-Hill (2003)

David H.Allen, Walter E.Haisler, ‘INTRODUCTION TO AEROSPACE STRUCTURAL ANALYSIS’ , John Wiley & Sons (1985)

Image

http://www.ansys.com/Industries/Electronics+&+Semiconductor/Defense+&+Aerospace+Electronics

http://www.theregister.co.uk/2010/11/10/panasas_pas12/

http://www.mece.ualberta.ca/~wmoussa/lab/research.htm

http://www.innoventengg.com/ansys-fluent.html

http://www.esscano.com/page.asp?page_ID=14

http://news.investors.com/photopopup.aspx?path=ITc_111207.jpg&docId=593871&xmpSource=&width=1175&height=750&caption=Ansys+software+is+used+to+model+the+flow-path+lines+for+two+rockets+on+this+military+helicopter

http://www.sme.org/MEMagazine/Article.aspx?id=49599&taxid=1419

http://ari3f.wordpress.com/2007/03/08/wisata-ke-finite-element-method/