static and fatigue simulation of aircraf

1

STATIC AND FATIGUE SIMULATION OF AIRCRAFT LANDING GEAR M.VIJAYAN 1, JENITH N BARNABAS 2, K.HARIRAM 3

Department of Mechanical Engineering, Udaya School of Engineering, Vellomodi-629204, Kanya kumari, Tamilnadu, INDIA1, 2, 3

Tel : + 91978886149991 ,+ 9180565656562,+9194434950933 .

[email protected]@gmail.com2

ABSTRACT: The main objective of this project is to analyse the aircraft landing gear with different material .All the parts of landing gear designed by Pro-E Software but Static and fatigue simulation done by Solid works Soft ware.Current we are landing gear material is Alloy Steel .In this fatigue simulation, the damage percentage and life of axle is 0.0178961 and 5587.82 cycles respectively .Instead of this material is introducing carbon steel on that part .After static and fatigue simulation completed , the result value of damage percentage and life of axle is higher than previous material. . .Key words: (Landing Gear , Alloy Steel , Cast Caron Steel , Fatigue)

1.INTRODUCTION

Another aircraft major component that is needed to

be designed is landing gear (undercarriage). The

landing gear is the structure that supports an

aircraft on the ground and allows it to taxi, take-off,

and land. In fact, landing gear design tends to have

several interferences with the aircraft structural

design. In this book, the structural design aspects of

landing gear are not addressed; but, those design

parameters which strongly impact the aircraft

configuration design and aircraft aerodynamics will

be discussed.

1.Wheel hub

2.Lower Link

3.Upper Link

4.Axle

5.Piston

The landing gear usually includes wheels, but some

aircraft are equipped with skis for snow or float for

water. In the case of a vertical take-off and landing

aircraft such as a helicopter, wheels may be

replaced with skids. illustrates landing gear primary

parameters. The descriptions of primary parameters

are as follows. Landing gear height is the distance

between the lowest point of the landing gear (i.e.

bottom of the tire) and the attachment point to the

aircraft. Since, landing gear may be attached to the

fuselage or to the wing; the term height has

different meaning. Furthermore, the landing gear

height is a function of shock absorber and the

landing gear deflection. The height is usually

measured when the aircraft is on the ground; it has

maximum take-off weight; and landing gear has the

maximum deflection (i.e. lowest height).

LANDING GEAR CONFIGURATION:

The first job of an aircraft designer in the landing

gear design process is to select the landing gear

configuration. Landing gear functions may be

performed through the application of various

landing gear types and configurations. Landing

gear design requirements are parts of the aircraft

general design requirements including cost, aircraft

performance, aircraft stability, aircraft control,

maintainability and operational considerations. In

general, there are ten configurations for a landing

gear as follows:

1. Single main

2. Bicycle

3. Tail-gear

4. Tricycle or nose-gear

2

5. Quadricycle

6. Multi-bogey

Transport aircraft McDonnell Douglas MD-88 with

tricycle landing gear:

3. Bomber aircraft B-52 Stratofortress with

quadricycle landing gear is using parachute during

a landing operation

4. Transport aircraft Boeing 747 with multi-bogey

landing gear:

The features and the technical descriptions of each

landing gear configuration will be presented in this

section. The landing gear configuration selection

process includes setting up a table of features that

can be compared in a numerical fashion. It needs to

be clarified that for simplicity the term “gear” or

“wheel” is sometimes employed for a single strut

and whatever that is connected to it which

comprises such items as tire, wheel, shock

absorber, actuators, and brake assembly. Hence,

when the term “nose-gear” is used, it refers to a

landing gear configuration; while when the term

“nose gear” is employed, it refers to a gear that is

attached under the fuselage nose. In general, most

general aviation, transport and fighter aircraft

employ tricycle landing gear, while some heavy

weight transport (cargo) aircraft use quadricycle or

multi-bogy landing gear. Nowadays, the tail-gear is

seldom used by some GA aircraft, but it was

employed in the first 50 years of aviation history by

majority of aircraft.

MODELLING:

Pro-E Model of Aircraft landing Gear Parts:

3

1.Wheel Hub:

2.PISTON:

3.STRUT:

4.AXLE:

4.UPPER LINK:

5.LOWER LINK:

4

ASSEMBLE OF PARTS:

CONVERT PRO-E ASSEMBLE MODEL INTO

IGES FORMAT:

After all the parts assembled in Pro-E,

save that model into IGES format shown below:

Assemble model →Click file → Save as → Click

save as type → Select IGES(*igs.) → Ok.

IMPORTING PRO-E ASSEMBLE MODEL INTO

SOLIDWORKS:

When the solid works window open, the

following steps are involved for importing the

assemble model,

Open Solid works 2015 (icon) → Click open →

Click open type

→ Select IGES(*igs) → Select assemble model →

Click Open.

SIMULATION RESULTS

1.ALLOY STEEL

MATERIAL PROPERTIES:

LOADS AND FIXTURES:

Properties

Name: Alloy Steel

Model type: Linear Elastic

Isotropic

Default failure

criterion:

Max von Misses Stress

Yield strength: 620.422 N/mm^2

Tensile strength: 723.826 N/mm^2

Elastic modulus: 210000 N/mm^2

Poisson's ratio: 0.28

Mass density: 7700 g/cm^3

Shear modulus: 79000 N/mm^2

Thermal expansion

coefficient:

1.3e-005 /Kelvin

Fixture name Fixture Image Fixture Details

Fixed

Entities: 4 faces Type: Fixed

Geometry

Load name Load Image Load Details

Load

Entities: 1 face Force Valu s:

-289395 N

Gravity

Reference: Plane 2 Values: -9.81 Units: SI

5

STUDY RESULTS:

FATIGUE SIMULATION:

Type Min Max

von Misses Stress

0.000184536 N/mm^2 (MPa)

Node: 10069

863.427 N/mm^2 (MPa)

Node: 21740

Type Min Max

Resultant Displacement

0 mm

Node: 19871

0.431681 mm

Node: 6712

Type Min Max

Damage plot 0.01247 Node: 1 0.0178961 Node: 21781

Type Min Max

Life plot 5587.82 cycle Node: 21781

8019.25 cycle

Node: 1

6

2.CAST CARBON STEEL

MATERIAL PROPERTIES:

STUDY RESULTS:

Type Min Max

von Misses Stress

1.2739e-006 N/mm^2 (MPa)

Node: 4411

227.215 N/mm^2 (MPa)

Node: 21781

FATIGUE SIMULATION:

STUDY RESULTS:

Type Min Max

Damage percentage

0.01247

Node: 1

0.0176355

Node: 21781

PROPERTIES

Name: Alloy Steel (SS)

Upper link lower link ,piston strut ,wheel hub

Model type: Linear Elastic Isotropic

Default failure criterion:








Thermal expansion coefficient:

1.3e-005 /Kelvin

Name: Cast Carbon Steel (axle)

Model type: Linear Elastic Isotropic

Default failure criterion:








Thermal expansion coefficient:

1.2e-005 /Kelvin

7

CONCLUSION:

Aircraft landing gear modeled and simulated by

Pro-E and Solid works Software respectively

.Simulate landing gear with alloy steel material and

obtained stress, displacement, strain results from

solid works static simulation. Simulate landing gear

with alloy steel material and obtained damage

percentage and life results from solid works fatigue

simulation .Simulate landing gear with cast carbon

steel material and obtained stress, displacement,

strain results from solid works static simulation.

Simulate landing gear with cast carbon steel

material and obtained damage percentage and life

results from solid works fatigue simulation. Then

compare all results with each material and choose

favorable material for landing gear axle part.Finally

cast carbon material is suitable material for aircraft

landing gear as per its results.

REFERENCES:

1. Norman S. Currey, Aircraft Landing Gear

Design: Principles and Practices, AIAA, 1988

2. Roskam J., Roskam’s Airplanes War Stories,

DAR Corp., 2006

3. FAR Part 23.473, Federal Aviation

Administration

4. Russell C. Hibbeler, Engineering Mechanics:

Statics, 12th Edition, Prentice Hall, 2009

5. Budynas R. G. and Nisbett J. K., Shigley's

Mechanical Engineering Design, McGraw-Hill, 9th

Edition, 2011

6. Aircraft Tire Data, The Goodyear Tire & Rubber

Company

7. Aircraft Tire Data, Bridgestone Corporation

8. Paul Jackson, et al., Jane’s all the world’s

aircraft, Jane’s Information Group, several years

9. Green W. L., Aircraft Hydraulic Systems: An

Introduction to the Analysis of Systems and

Components, Wiley, 1986

10. Robert L. Norton, Design of Machinery: An

Introduction to the Synthesis and Analysis of

Mechanisms and Machines, McGraw-Hill, 2008

11. Arthur G. Erdman, George N. Sandor, Sridhar

Kota, Mechanism Design: Analysis and Synthesis,

4th Edition, Prentice Hall, 2001

12. Anon, MIL-F-1797C, Flying qualities of

piloted airplanes, Air force flight dynamic

laboratory, WPAFB, Dayton, OH, 1990

Type Min

Max

Life 5670.37 cycles

Node: 21781

8019.25 cycles

Node: 1

static and fatigue simulation of aircraf

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