Degree Fyp Thesis

AIRFRAME DESIGN AND MANUFACTURE OF ULTRALIGHT FUSELAGE

“I declared that this thesis is the result of my own work except the ideas and summaries which I have declared their sources. The thesis has not been accepted for any degree and is not concurrently submitted in candidature of any degree. “

t hesis and in my point of view this thesis is qualified in term “I declared that I read this thesis of scope and quality for the purpose of awarding the Bachelor of Engineering (Hons) Mechanical. “

AIRFRAME DESIGN AND MANUFACTURE OF ULTRALIGHT FUSELAGE

MOHD ZAIREN BIN MOHAMMAD ZIN (2009848424)

ACKNOWLEDGEMENT

In the name of Allah, Most Gracious, Most Merciful. I wish to appreciate my supervisor, Prof. Dr. Ir. Wahyu Kuntjoro for giving much of his time and experience throughout the project from beginning until the end. I am very

ABSTRACT

Ultralight aircraft airframe is an extremely lightweight aircraft and categorized as an experimental aircraft by Federal Aviation Regulations (FAR). FAR 103 states that the ultralight airframe design is less than 70 kg if unpowered with fuselage and wing

TABLE OF CONTENTS

 ACKNOWLEDGEMENT  ACKNOWLEDGEMENT ................... ......... ................... .................. ................... ................... .................. ................ ....... i  ABSTRACT ................... ......... ................... ................... ................... .................. .................. ................... ................... ............... ...... ii LIST LIST OF FIGURES: FIGURES: .................... .................................... ................................. .................................. ......................... ........ v

CHAPTER 3:

2.6

Finite Element Method .............................................................. 16

2.7

Material Strength .................. ......... ................... ................... .................. ................... ................... .............. ..... 18

METHODOLOGY................... .......... ................... ................... .................. ................... ................... .................. ............. .... 21 3.1

Introductions ............................................................................. 23

3.2

Visit Malacca 4B Flying Club .................................................... 23

3.3

Material Source ........................................................................ 24

3.4

Preliminary Design.................................................................... 25

3.5

Fuselage Design ....................................................................... 27

3.6

Manufacturing Process ............................................................. 28

3.7

Material Testing ........................................................................ 40

3.8

Finite Element Analysis of Fuselage Airframe ................... .......... ................. ........ 44

3.9

Fuselage Structure Test ........................................................... 47

3.10  Assembly of Airframe Airframe.................. ......... ................... ................... ................... ................... ................. ........ 49 49 CHAPTER 4:

RESULTS AND DISCUSSIONS................

50

LIST OF FIGURES:

Figure 2.1: Ultralight Ultralight Quicksilver MX Sprint [15] ................... ......... ................... .................. ................... ................... ............. .... 6 Figure 2.2: Fuselage Airframe Airframe Design [16] ................... ......... ................... ................... ................... .................. .................. ............ ... 8 Figure 2.3: BWB Baseline II-E2 UAV airframe model [6] .................. ......... ................... ................... .................. ........... 9

Figure 3.12: Sample of square cutoff from 33mm tube aluminium hollow ....... ............ .......... .. 30 Figure 3.13: Hydraulic Hydraulic Swing Beam Shearing Shearing Machine............... ................... .......... .................. ............. .... 30 Figure 3.14: The plate for different different joints of the trike .................. ........ ................... .................. ................... ............... ..... 31 Figure 3.15: Using Drilling Machine Machine for drilling drilling process of joints .................. ......... ................... ................ ...... 31 Figure 3.16: Precision Lathe Machine ......................................................................... 32 Figure 3.17: Threading the shaft ................................................................................. 32 Figure 3.18: Shaft of rare wheel assembly along with dipole joint .................. ......... ................... ............. ... 33 Figure 3.19: Rare Left side of Trike Joints................................................................... 33 Figure 3.20: The bending bending process of seat frame ................... .......... ................... ................... .................. ................... .......... 34 Figure 3.21: Seat assembly process ........................................................................... 34 Figure 3.22: Front trike joint ........................................................................................ 35 Figure 3.23: Trike assembly ........................................................................................ 35 Figure 3.24: Foot Paddle ............................................................................................ 36 Figure 3.25: Nose plate of Trike .................................................................................. 36 Figure 3.26: Grinding process for most edges of the airframe .................. ......... .................. .................. ........... 37 Figure 3.27: Assembly of front wheel at Trike nose .................. ......... ................... ................... .................. ................ ....... 37 Figure 3.28: Front Front view of trike.................. ......... .................. ................... ................... ................... ................... .................. .................. ........... 38

Figure 4.4: Deformation of Airframe at 3.8g ................................................................ 58 Figure 4.5: Plot Results for maximum Stress at 3.8g .................................................. 58 Figure 4.6: Deformation of Airframe at 2.5g ................................................................ 59 Figure 4.7: Plot Results for maximum Stress at 2.5g .................................................. 59 Figure 4.8: Deformation of Airframe at 1g ................................................................... 60 Figure 4.9: Plot Results for maximum Stress at 1g ..................................................... 60 Figure 6.1: Trike Part Design ...................................................................................... 78 Figure 6.2: 6.2: Trike Joint Design ..................................................................................... 79 Figure 6.3: Trike Nose Design .................................................................................... 80 Figure 6.4: Trike Part Design ...................................................................................... 80

LIST OF TABLES:

Table 2.1: Lift Force Based on BWB Area Percentage ............................................... 17 Table 2.2: Weight Percentage Percentage................... .......... .................. ................... ................... ................... ................... .................. .................. ........... 17 Table 2.3: Distribution of Weight ................................................................................. 17

LIST OF ABBREVIATION: ABBREVIATION:

BWB

Blended Wing Body

CFD

Computational Computation al Fluid Mechanic

LIST OF SYMBOLS:

 Ag

Silver

 Al

Aluminium

Li

Lithium

Ll

Length

n

Load Factor

Mg

Magnesium

Mn

Manganese

Na

Sodium

Ni

Nickel

P

Phosphorus

Pb

Lead

Si

Silicon

Sn

Tin

CHAPTER 1:

INTRODUCTION

1.1

Background of study

Ultralight is defined as extreme light weight airplane. airplane. Airframe is defined as the body of an aircraft as distinct from its engine. Ultralight airframe is the body of an aircraft at minimum weight without consideration of its engine. The project produces the result of strength requirement or static behavior of the ultralight airframe fuselage part.

The fuselage of the ultralight airframe has several sections included with the connections to other important sections sections such as the wing. I t consists both trike and empennage components. components. The trike is the part of the cockpit where the pilot is. It is a main component used for installations installations of other part such as the front wings, the empennage, the power plant (engine and fuel compartment) and the controls of the airframe. The study is done as such in consideration of all the loadings applied at those parts of the fuselage where the airframe is static.

Ultralight airframe design gives further understanding understanding of the specifications of the

standard given to determine the safety feature of the airframe design of the fuselage f uselage of the ultralight aircraft as it is the main body for the whole product.

1.2

Problem Statement

Design of ultralight airframe fuselage deals with the safety consideration consideration in use during aviation purpose. It could bring harm to the user and public without proper analysis done on the airframe structure. There are several reports considering the safety of the structure is not valid. 13 th March 2010, a 54-year-old ultralight ultralight pilot (Antares) was severely injured during an accident in Chugiak, Alaska where there was evidence of in-flight airframe failure [11]. This proves t hat the structure of the ultralight airframe can fail anytime without pr ior ior to the user’s knowledge. knowledge. Therefore, it is mandatory to check the safety of airframe design of ultralight aircraft of the trike to minimize the damage.

1.4

Scope of Project

The study is done by adopting the design of existing ultralight fuselage airframe, the Quicksilver MX 2S design. It is also to consider the regulations established established for the type of aircraft. This is done based on the airframe selection and its static behavior. The material strength is tested by sparking test, bending test and tensile test. Analysis can be done by implementing implementing Finite Element Method for the fuselage of the ultralight airframe.

1.5

Significance of Project

The importance of this project is to give out more understanding for the ultralight airframe in this country. The airframe itself is important in terms of the

CHAPTER 2:

LITERATURE REVIEW

Figure 2.1: Ultralight Quicksilver MX Sprint [15]

Ultralight is identified as a vehicle vehicle not aircraft. Because they are vehicles vehicles and not aircraft, this regulation allows allows individuals to operate ultralight vehicles without requiring FAA pilot or vehicle certification. Upon publishing Part 103 the FAA said it did not wish to issue pilot certificates for ultralight operators. FAA understood individuals who want to fly ultralight should participate in industry-established industry-established self-regulation and

2.2

Ultralight Regulations

There are several types of regulations needed to be considered before building building the airframe of the ultralight which determines determines the expected and limitations of the specifications of the airframe. The first important part of the regulations is from the airframe weight. One of the regulations is the Federal Aviation Regulations (FAR) [4] (Page 23).

There are several parts within the regulation. The basic part is the FAR23 for determining the minimum takeoff weight. Ultralight is an experimental aircraft within the special category but the airworthiness certificate can be deducted as a normal category aircraft [11].The regulation states as follows: 

The Maximum Takeoff Weight; normal, utility or acrobatic category ≤ 5670kg.



The Maximum Takeoff Takeoff Weight; commuter category ≤ 8618kg. 8618kg.

Ultralight also has its own unique regulations within the FAR. Ultralight is within the

(4) Has a power-off stall speed which does not exceed 44.5 km/h calibrated airspeed. 103.3 Inspection requirements. (a) Any person operating an ultralight vehicle under this part shall, upon request, allow the Administrator, or his designee, to inspect the vehicle to determine the applicability of this part. (b) The pilot or operator of an ultralight vehicle must, upon r equest of the Administrator, furnish satisfactory evidence that the vehicle is subject only to the provisions of this t his part. 103.5 Waivers. No person may conduct operations that require a deviation from this part except under a written waiver issued by the Administrator. Administrator. 103.7 Certification and registration. (a) Notwithstanding any other section pertaining to certification of aircraft or their parts

The design of the fuselage is considered along with the positions of each component of the airframe within the fuselage. It is also where the position of the pilot is located as to initiate the controls of the aircraft along the rest of the airframe parts design of the aircraft such as the positioning of the wingspan, the engine or power plant, pilots and passengers seats, the empennage and back wings. It is an important part within the airframe of every aircraft design as the design requires the determination of the center of gravity for the whole airframe [9] (Chapter 5, page 86).

There are several examples of fuselage design such as the Unmanned Aerial Vehicle (UAV) at Universiti Teknologi MARA (UiTM) which is a radio controlled aircraft called “Kenyalang” of the conduct a research titled Unmanned Aerial A erial Vehicle with Fuel Cell Propulsion System. The airframe is designed based on balsawood rib with aluminium framework framework that holds the engine, fuel cell, hydrogen tank, remote control, instrumentation and landing gear position; and the fuselage is carbon fiber laminated.

Other example is based on the Blended Wing Body (BWB) Baseline I1-E2 Unmanned Aerial Vehicle (UAV). This UAV relates to the combination of both the

development of Blended Wing Body concept. This research is in correlation to the Unmanned Aerial Vehicle (UAV). Using the fundamentals of fluid mechanics, 0.3 Mach number of the BWB model can be analyze with Computational Fluid Dynamics (CFD) to various elevator deflection sequence. sequence. Finite Element Model of the BWB is designed using ANSys software, the same software applying the CFD function, to do the structural analysis. Without elevator deflection, it is tested through wind tunnel analysis of 0.1 Mach number for the wing pressure distribution. distribution. This is done to confirm t he reliability of CFD and wind tunnel test. BWB design sets the pressure drag as crucial to the total drag compared to conventional designs due to intrinsic nature of lower surface to volume ratio of the BWB shape [6].

2.4

Ultralight Airframe example

2.4.1 The wing structure

Microlight possesses flex wings that have complex wing structure than conventional conventional wing. The leading edges for the wing primary structure with two segmented tubes of 4.5-5.5m long are joined together at the nose to the keel tube extended from the trailing edge as shown in Figure 2.4 that runs the length of the wing. The wing cover seen as a fabric is made from a polyester Dacron, Dacron, a high strength nonporous fabric which is overextended at the wingspan like a sail. During rigging, the rigidity and form are ensured by cross tubes that are being hinged to each other overhead the keel tube and half-span of the leading edges at the center where the structure is applied considerable internal loads. The form of the wings is formed based on the tensioning cable where it runs throughout the length of the keel. The above statement can be identified using the following Figure 2.5.

Based on Figure 2.4, the end view of the wing shows an A-frame that have a basebar and two uprights which are clearly demonstrated in Figure 2.5. The basebar plays a vital role in flight control giving the roll and pitch control during normal flight. It is also the principal structure of supporting the tension via flying cables and wires the wing loads outboard of the leading edge and cross-tube junction. The most part that is compressed is the A-frame uprights and the leading edge of the inboard sections. The ideal location of then basebar is critical as it aids in the correct control of the airplane where some may refer to it as the ‘piano‘piano -playing position’.  Adjusting the position position of the basebar basebar during wing wing development development is done usually usually through the adjustment of the front rear wires located at nose to the end of the basebar as displayed in Figure 2.5. These T hese wires are fundamentally important for weight shifting the wings against the structure of the aircraft as it locates the base bar and provides maneuvering for wing pitch control. Structural wires are 20-60mm away jointed together as parallel wires to provide more clasps for the form and shape of the aircraft. Different than those lines function are the luff lines which yield small amount of actual load in flight although aerodynamically crucial to the system. Therefore, the

The wingspan is 8 to 10 meters long and the length of the leading edge or nose till the trailing edge is 3 meters long. The wing is weight shifted with no tail of horizontal or vertical stabilizer as any normal airplanes. The trike is hanged to the wings directly along with the crew, power plant and undercarriage which are gripped by the hang point with a joint of all three axes free degree of freedom to f reely rotate in pitch and roll without interference. The joint is fundamentally stable with no pendular stability but provided longitudinal stability. The arrangement of the twist of the wing between root and tip, the reflex that is at the inboard trailing edge shaped as an inverted airfoil and the wing sweep gives the longitudinal longitudinal stability that is behind the center of gravity (CG). It gives the down force at the wingtips. The minimized washout rods known as tip sticks are cantilever rods connected through the leading edge perpendicularly from beneath the wing edge supports the sail of t he wing that tends to smoothen out during high speed operation of the aircraft. The sail tendency to f latten causes the decreasing in static stability which is intolerable affecting loss in longitudinal stability. stability. The tipsticks acts as a limiter for the

Figure 2.7: Trike structure Monopole is the bone structure and most vital part of the trike where it holds up the main wheels to the hang point vertically as a pole. All the parts such as wing, power plant, main wheels and the seat are joined at the structure of monopole. The monopole is set up so that it can withstand dire stress failure such from f atigue crack propagation. propagation. The design also includes cable at the center of the monopole itself to provide safety precautions towards the design that connects the engine mount or undercarriage connections to the hang point.

2.5

Maneuvering Control System

The maneuvering system consists of several parts which hold onto the positioning control in-plane and height. There are several control features for ultralight which have 3 axes of motions. There are the elevator motion, rudder motion, and ailerons motion. These parts are crucial for the airframe to be able to produce motion airborne and for taking off [1] (page 230). The parts produce the following motions: Elevator Motion



 

Climbing/descending

o

 

Pitching



Rudder Motion

o

Side slipping/Skidding slipping/Skidding

o

o

 

Yawing



Ailerons Motion  

o

Rolling

Using motion of control directly from the control yoke 1.

Controls the elevator for up and down motion

2.

Controls the ailerons for rotational motions

b) Horizontal motion The motion for the rudder is based on footwork which moves left when the left foot is pressed and moves right when the right foot is pressed.

2.6

Finite Element Method

Using Finite Element Analysis, the analysis for static structure beam or frame

modules area. The following table shows the distribution of weight and lift force with respect to BWB modules area [6]. Table 2.1: Lift Force Based on BWB Area Percentage

Table 2.2: Weight Percentage

Table 2.3: Distribution of Weight

BWB Static Results is shown by the resultant BWB stress tensor and displacement displacement contour. It was found that the maximum stress value is 81.1 MPa at node 238, and the maximum displacement value is 156.0 mm at node 1463. The maximum stress occurs at the point connection between wing body and canard modules. The maximum displacement displacement was found to be at the t he wing tip of canard [6].

Table 2.4: Aluminium Alloy Properties Comparison  Aluminium Alloy Alloy Properties

6063-T6

7075-T6

Ultimate Tensile Strength

241 MPa

572 MPa

Tensile Yield Strength

214 MPa

503 MPa

Modulus of Elasticity

68.9 GPa

71.7 GPa

Density

2.7g/cc

2.81g/cc

Poisson’s Ratio

0.33

0.33

The Stress-Strain relationship allows the identification of mechanical properties such as the yield strength and modulus of elasticity. The following figure shows a stress-strain curve.

1: True elastic limit 2: Proportionality limit 3: Elastic limit 4: Offset yield strength

CHAPTER 3:

METHODOLOGY

3.1

Introductions

In this project, several processes have been carried out and were included in the research methodology. methodology. The processes consist of the study on the structure of airframe fuselage, build the airframe, conduct the test analysis and gain data, hence compare with the theoretical and the actual value of the adopted design of the ultralight airframe.

3.2

Visit Malacca 4B Flying Club

During the duration of the project, the flying club for ultralight ultralight in Batu Berendam, Melaka has been visited to carry out actual process of understanding the mechanism built for the airframe of the aircraft.

Figure 3.2: MX Sport 2S in Melaka The preliminary design is set up to be the same model, the Quicksilver MX Sport 2S. The design of the fuselage is tampered to be a single seated instead of a double seated aircraft. The entire dimension is obtained by measuring the design using measuring tape.

Figure 3.4: Measurement of Material 

Aluminium hollow tube available



Diameter range of 25-38mm

Figure 3.8: top view of design

Figure 3.10: Disc Cutting Machine The material is based on type 26mm and 33mm hollow tubes. The following figure shows the materials cut.

Figure 3.12: Sample of square cutoff from 33mm tube aluminium hollow The figure shows the sample needed to be tested through sparking test at the foundry lab to obtain the chemical composition data sheet allowing identifying which grade the material belongs to.

Figure 3.14: The plate for different joints of the trike The hollow beam of each joint is then drilled respective to the length of the hole of each  joint.

Figure 3.16: Precision Lathe Machine The result of the lathe process is then threaded out to provide an up thread for the shaft to be bolted together to fix the wheel in place as illustrated in Figure 3.17.

Figure 3.18: Shaft of rare wheel assembly along with dipole joint The figure shows that the joint for rare dipole and the shaft of rare wheel is being assembled together to provide strong connection in and out of the tube. The tube t ube itself is 33mm hollow of 1.37 thicknesses. By inserting the shaft, the joint is reinforced and less distortion can occur at the point as the plate of t he rare dipole holds together the

Figure 3.20: The bending process of seat frame The seat frame is then assembled and connected together with the seat as shown in the Figure 3.21.

Figure 3.22: Front trike joint The trike structure can be fully assembled as shown in the following Figure 3.23.

Figure 3.24: Foot Paddle The front or nose of the trike is then plated together to from a platform for the support of the front wheels. It is designed base on the latter Quicksilver MX 2 Sprint visited at Melaka airport.

Figure 3.26: Grinding process for most edges of the airframe The plate is drilled to produce a hole of diameter 34mm to provide shaft hole for the support of the wheel along for maneuvering purpose of the wheel to rotate. The front wheel support is done simply by bending of plate and welded together to a shaft. The smooth rotation is provided by the installed ‘burger bearing’ that functions solely as a bearing on two plate surfaces.

Tie rods

Figure 3.28: Front view of trike

Figure 3.30: Preliminary stage Trike

3.7

Material Testing

The structure of the airframe needed to be tested in terms of material strength. Several test such as sparking test, bending test and tensile test were conducted to evaluate the aluminium strength in terms of the Modulus of Elasticity and Yield Strength.

3.7.1

Sparking Test

The analysis of the fuselage can be done using the ANSys software. Before the analysis can be done, testing to determine the material properties is carried out. The purpose of the testing is originated to identify the strength of t he material used based on standards given. The first is to identify which category the material belongs to and the chemical composition. A short test for sparking is done based on sample in Figure 3.12.

This test is operated using simple mechanism without without accordance to any other standard. The bending test is carried out to search for the value of Modulus of Elasticity for the hollow beam.

Figure 3.33: Simple Bending Test Configuration Figure 3.33 displays the set-up of simple apparatus which includes the clamp to fix the

Length, l Deflection, v

Load, 40.05N

Figure 3.35: Deflection of 33mm hollow beam The result of the test is recorded on the piece of paper and all measurements. The experiment is repeated to get a more accurate value of the reading.

Figure 3.37: Specimen of 26mm Tube The samples are tested out in to the machine and the results are based on the input key of dimension for each cutoff sample. The dimension of the sample is based on the European Standard EN 10002-1: 2001. The dimension is as follows:

The cross-section area, Al = 0.000017995 The sample was tested and resulted as follows.

Figure 3.39: Tensile Sample Test after Run

Figure 3.40: Section Data input By plotting the node sequence in coordinate system, the data can be obtained in the

This is based on the weight balance configuration configuration for the t he airframe fuselage. The following is the force applied on the nodes of the FEA airframe fuselage as shown in Table 3.2. Table 3.2: Load Distribution Node

1g Force(N)

2.5g Force(N)

3.8g Force(N)

Part/Component Part/Component

1

-49.05

-122.625

-186.39

Fuel Tank

-206.53

-516.32

-784.8

Pilot

-196.2

-490.5

-745.56

Powerplant Powerplant

43, 44, 45, 46 53

Table 3.3: Fixed Support Fuselage Boundary Condition:

Fuel Tank Load

Engine/ Powerplant Load

Pilot distributed Load

Figure 3.42: ANSys Load Definition

96.3cm

Figure 3.43: Hanging on cranes The Figure 3.43 shows the airframe of the trike being held at the position of the fixed

3.10

Assembly of Airframe

The airframe was assembled together. The fuselage was completed with the wings and  joined as shown: shown:

CHAPTER 4:

RESULTS AND DISCUSSIONS

Table 4.2: Chemical Properties of Aluminium Alloy 6063 (%)  Al =

Si =

Fe =

Cu =

Mn =

Mg =

Cr =

Ti =

Zn =

remainder

0.2~0.4