1

ANALYSIS OF HYBRID ALUMINIUM/COMPOSITE

DRIVE SHAFT UNDER STATIC TORSION

A SEMINAR REPORT SUBMITTED TO

THE NATIONAL INSTITUTE OF ENGINEERING

(AUTONOMOUS UNDER V.T.U.)

In partial fulfilment for the award of degree of

Master of Technology

In

MACHINE DESIGN

SUBMITTED BY

PINGULKAR PUSHRARAJ RAMCHANDRA

2014PG0121

Under the guidance of

Dr. Suresha B.

Professor

Department of Mechanical Engineering

The National Institute of Engineering, Mysore

DEPARTMENT OF MECHANICAL ENGINEERING

THE NATIONAL INSTITUTE OF ENGINEERING

MYSORE 570 008

2014 -2015

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DEPARTMENT OF MECHANICAL ENGINEERING

THE NATIONAL INSTITUTE OF ENGINEERING

MYSORE 570 008

CERTIFICATE

This is to certify that Mr. Pingulkar Pushparaj Ramchandra of 1st

semester M.Tech (Machine Design) has successfully completed a seminar

entitled Analysis of Hybrid Aluminium/Composite Shaft Under Static

Torsion for the award of the degree of Master of Technology in Machine

Design by Visvesvaraya Technological University, Belgaum for the academic

year 2014 2015.

Dr. Suresha B. Professor & P.G. Coordinator

Dept. of Mechanical Engineering

The National Institute of Engineering

Mysore 570 008

Dr. N. V. Raghavendra Professor & H.O.D.

Dept. of Mechanical Engineering

The National Institute of Engineering

Mysore 570 008

Dr. G. L. Shekar Principal

The National Institute of Engineering

Mysore 570 008

Examiners:

1.

2.

3

Acknowledgements

The satisfaction and euphoria that accomplished the successful completion of any task

would be incomplete without the people who made it possible, whose constant guidance and

encouragement crowned out effort with success.

I take this opportunity to express my gratitude to my guide Dr. Suresha B., Professor,

Department of Mechanical Engineering, for his valuable guidance. I am greatly indebted to his

help, which has been of immense value and has played a major role in bringing this to a

successful completion.

My heartfelt thanks to Dr. N. V. Raghavendra, Head, Department of Mechanical

Engineering, and Dr. G L Shekar, Principal for providing us a serene and healthy environment

which helped in concentrating on the task.

Finally I like to express my profound gratitude to my parents for their constant

encouragement and support through my life.

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Abstract

A hybrid aluminum/composite is an advanced composite material that consists of

aluminum tube wound onto outside by layers of composite material. The result of this

combination is a hybrid shaft that has a higher torsional strength, a higher fundamental natural

bending frequency and less noise and vibration. This work dealt with investigation of

maximum torsional strength of the hybrid aluminum/composite shaft for different winding

angle, number of layers and stacking sequences. The hybrid shaft consists of aluminum tube

wound outside by E-glass or carbon fibers/epoxy composite or their hybrids. The finite element

method had been used to analyse the hybrid shaft under static torsion. ANSYS finite element

software was used to perform the numerical analysis for the hybrid shaft. Full scale hybrid

specimen was analysed. Elasto-plastic properties were used for aluminum tube and linear

elastic for composite materials. The results showed that the static torque capacity was

significantly affected by changing the winding angle, stacking sequences and number of layers.

The maximum static torsion capacity of aluminum tube wound outside by six layers of carbon

fiber/epoxy composite at winding angle of 45 was 295 N m. Good agreement was obtained

between the finite element predictions and experimental resuts.

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Contents

Certificate

2

Acknowledgements

3

Abstract

4

Contents

5

List of figures

6

List of tables

7

1 Introduction

1

2 Theory 9

2.1 Composite material 9

2.2 Concept of lamina and laminate 9

2.3 Laminate code 9

2.4 Winding angle in filament winding 10

3 Finite element analysis of hybrid aluminium/composite shaft under static

torsion

11

3.1 ANSYS as a finite element analysis tool 11

3.2 The finite element model of hybrid aluminium/composite specimen 11

3.3 Material properties 13

3.4 Boundary conditions

14

4 Finite element analysis results and discussion

15

4.1 Effect of winding angle and number of layers on torsional strength 15

4.2 Effect of stacking sequence on torsional strength 16

4.3 Effect of hybridization on torsional strength

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5 Comparison between experimental and finite element analysis results

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5.1 Torque versus angle of twist comparison 19

5.2 Comparison of maximum torque capacity 21

5 Conclusions

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6 References

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6

List of figures

Fig. 2.1 Laminates and their stacking sequences

Fig. 2.2 Winding angle in filament winding

Fig. 3.1 Configuration and dimensions of torsion test specimen

Fig. 3.2 Finite element meshes

Fig. 3.3 Idealized stressstrain curve for nonlinear property of the aluminum tube

Fig. 4.1 Failure indices of aluminum tubes wound by four layers of carbon and glass

fibers/epoxy

Fig. 4.2 Failure indices of aluminum tubes wound by six layers of carbon and glass

fibers/epoxy

Fig. 4.3 Effects of change stacking sequence on the failure indices for hybrid shaft

wound externally by four layers of glass and carbon fiber/epoxy

Fig. 4.4 Effect of hybridization on the failure indices for aluminum tube wound

externally by four layers of winding angle at 45

Fig. 4.5 Effect of hybridization on the failure indices for aluminum tube wound

externally by six layers of winding angle at 45

Fig. 4.6 Failure indices for aluminum tube wound externally by [+45/-45/90/90] for

different composite materials

Fig. 5.1 Torque versus angle of twist comparison for aluminum tube wound

externally by [+45/-45] laminate for different composite materials

Fig. 5.2 Torque-angle of twist comparison for aluminum tube wound externally by

[+45/-45]2 laminate at different composite materials

Fig. 5.3 Torque-angle of twist comparison for aluminum tube wound externally by

[+45/-45]3 laminate for different composite materials

Fig. 5.4 Comparison of torsion capacities comparison between experimental and

finite element analysis for aluminum tube wound by glass fiber/epoxy

composite

Fig. 5.5 Comparison of torsion capacities comparison between experimental and

finite element analysis for aluminum tube wound by carbon fiber/epoxy

composite

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List of tables

Table 1 Laminates and their stacking sequences

Table 2 The mechanical properties for composite materials

Table 3 Effective properties of the orthotropic monolithic model

Table 4 Mechanical properties of aluminum (AA6063-T4)

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1. Introduction

Substituting composite structures for conventional metallic structures has many

advantages because of higher specific stiffness and strength of composite materials. Advanced

composite materials seem ideally suited for long, power drive shaft applications. Their elastic

properties can be tailored to increase the torque and the rotational speed at which they operate.

Polymer matrix composites such as carbon/epoxy or glass/epoxy or their hybrids have been

successfully used as propeller shafts to transfer torsional loads in many aerospace applications.

Apart from higher specific stiffness and strength, the polymer matrix composites also offer

superior vibration damping and fatigue characteristics as well as excellent corrosion resistance

over metals. However, because of the high material cost of carbon fiber/epoxy composite

materials, rather cheap aluminum materials may be used partly with composite materials such

as in a hybrid type of aluminum/composite drive shaft, in which the aluminum has a role to

transmit the required torque, while the carbon fiber/epoxy composite increases the bending

natural frequency.

In this work, finite element method was used to investigate maximum torsion capacity of

a hybrid aluminum/composite drive shaft. The hybrid shaft is consisting from aluminum tube

wounded outside by E-glass and carbon fibers/epoxy composite and their hybrids at different

winding angle, number of layers and stacking sequences. The finite element results were then

compared with the experimental results.

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2. Theory

In this chapter, a brief description of composites will be presented. Along with it, in the

following sections, the concept of a lamina, laminate, laminate code and winding angle in

filament winding of composite tubes will be discussed.

2.1. Composite materials

A composite is a structural material that consists of two or more combined constituents

that are combined at a macroscopic level and are not soluble in each other. One constituent is

called the reinforcing phase and the one in which it is embedded is called the matrix. The

reinforcing phase material may be in the form of fibers, particles, or flakes. The matrix phase

materials are generally continuous.

Some of the advantages of using composites over conventional materials include high

strength to weight ratio, high stiffness to weight ratio, high toughness, high corrosion

resistance, high wear resistance, high chemical resistance and high fatigue life

2.2. Concept of lamina and laminate

A lamina (also called a ply or layer) is a single flat layer of unidirectional fibers or woven

fibers arranged in a matrix.

A laminate is a stack of piles of composites. Each layer can be laid at various orientations

and can be made up of different material systems

2.3. Laminate code

A laminate is designated by using a special nomenclature. In this nomenclature, the fibre

orientation of all layers stacked in the laminate is given. The main steps to designate a laminate

are given as follows. Refer Fig 2.1.

1. The stacking of layers starts from the top of the laminate.

2. The stacking sequence gives the orientation of fibres with respect to global axis in

degrees.

3. The stacking sequence is enclosed in square brackets symbol, [ ]

4. The distinct layers or groups of layers are separated with a slash symbol, /

5. For repeated groups or layers, subscript n is used to designate the number of repetitions,

[ ]n

6. The symmetric laminate is designated by subscript S on the square bracket, [ ]S

7. The total stacking sequence is designated by subscript T, that is, by [ ]T.

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Fig. 2.1. Schematic of a laminate

2.4. Winding angle in filament winding

In filament winding of composite tubes, winding angle is defined as the angle the strand

or fiber has against an imaginary axis going in the axial direction on the outer surface of the

tube, as illustrated in Fig. 2.2. Wherever fiber orientation is used in this work, it follows this

definition.

Fig. 2.2. Winding angle in filament winding

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3. Finite element analysis of hybrid aluminium/composite drive shaft

3.1. ANSYS as a finite element analysis tool

Finite element algorithms has become a very powerful tool in order to analyse and solve

a wide range of engineering problems. Well developed, user friendly, well supported, flexible

and multi-field computer codes become a commercial field of engineering tools. One of the

challenging and most popular commercial all-purpose program used in finite element analysis

is the commercial finite element analysis software ANSYS. The finite element analysis of

the hybrid aluminium/composite drive shaft in this work was carried out using the ANSYS

software.

3.2. The finite element Model of hybrid aluminium/composite specimen

A full length finite element model was constructed for the 175 mm long hybrid shaft

under static torsion load in ANSYS. Fig. 3.1 shows the configuration and dimensions of the

hybrid specimen. Each layer on the hybrid shaft was modeled as a separate volume and meshed

using SOLID46 element. The layered element SOLID46 allows for up to 100 different material

layers with different orientations and orthotropic material properties in each layer. The element

has three degrees of freedom at each node and translations in the nodal x, y, and z directions.

Fig. 3.1. Configuration and dimensions of torsion test specimen

The layers were assumed perfectly bonded with the surface of aluminum tube. An eight-

node solid element, SOLID45, was used for the aluminum tube. The element is defined with

eight nodes having three degrees of freedom at each node translations in the nodal x, y, and z

directions. Fig. 3.2 shows the full scale finite element mesh for the hybrid aluminum/composite

drive shaft. The mapping mesh technique was used for the entire domain.

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Fig. 3.2. Finite element meshes

In general, phenomenological strength criteria such as maximum stress and Tsai-Wu

criteria are used to detect the failure status of composite laminates. Due to the complexity of

failure mechanisms in the hybrid aluminum/composite drive shaft, it is difficult to define an

applicable failure criterion. However, it is expected that the shear failure of the hybrid

aluminum/composite drive shaft is dominated by properties of carbon and glass fiber/ epoxy

composite layers, and the laminate fails just after the shear strain reached maximum failure

strain from experimental results in any direction. So, the maximum strain failure criterion was

used to predict the failure load in this study and the failure index determined. The failure index

is calculated as follows:

f

I

(1)

where I is the failure index, is the allowable angle of twist and f is the failure angle of twist

obtained experimentally. The fracture is expected to occur when the reached the ultimate

failure angle of twist, which means that the failure index equal one at the failure torque. Torque

failure indexes relations were found and comparisons with experimental results are presented.

Five cases were studied as shown in Table 1.

Glass fibers Carbon fibers

Case 1 [45]n [45]n

Case 2 [90]m [90]m

Case 3 [+45/-45/90/90] [+45/-45/90/90]

Case 4 [90+45/-45/90] [90/+45/-45/90]

Case 5 Glass + Carbon fibers

[(45)carbon/(45)glass]

Glass + Carbon fibers

[(45)carbon/(45)2,glass]

n = 1, 2 and 3; m = 2, 4 and 6

Table 1. Laminates and their stacking sequences

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3.3. Material properties

The elastic constants were found experimentally for composite materials as shown in

Table 2.

Properties Glass fiber/epoxy

composite

Carbon fiber/epoxy

composite

Longitudinal modulus E11 (GPa) 36.6 101.2

Transverse modulus E22 (GPa) 5.4 5.718

Shear modulus G12 (GPa) 4.085 4.346

Poissons ratio 12 0.3 0.31

Volume fraction Vf 0.476 0.545

Longitudinal strength XL (MPa) 618.9 1475.4

Transverse strength XT (MPa) 14 20

Shear strength 0 (MPa) 28 36

Table 2. The mechanical properties for composite materials

These properties were used with conventional laminate theory to calculate the theoretical

effective properties of the orthotropic monolithic model as shown in Table 3.

Properties Carbon fiber Glass fiber

45 90 45 90

Er (GPa) 9.789 5.71 9.072 5.4

E (GPa) 9.789 101.2 9.072 36.6

Gr (GPa) 5.22 4.346 4.368 4.085

r 0.126 0.0186 0.11 0.074

Table 3. Effective properties of the orthotropic monolithic model

Table 4 shows the mechanical properties of aluminium tube (AA6063-T4).

Tensile modulus, E (GPa) 69

Shear modulus, G (GPa) 26.5

Poissons ratio, m 0.3

Density, (kg/m3) 2700

Ultimate tensile stress (MPa) 131

Yield strength (MPa) 69

Shear strength (MPa) 69

Table 4. Mechanical properties of aluminum (AA6063-T4)

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The glass and carbon fiber/epoxy layers were modeled with homogenized linear elastic

orthotropic materials, and the elasto-plastic characteristic of aluminum tube was modeled by

inputting the stressstrain relationship to ANSYS program as shown in Fig. 3.3

Fig. 3.3. Idealized stressstrain curve for nonlinear property of the aluminum tube

3.4. Boundary conditions

The idea was to model the shaft in FEA subjected to pure torsion, for this, one end was

fixed with all the DOF arrested. On the other end the torque was applied as distributed forces

in tangential direction to the outside of the fixture of the hybrid shaft. The distributed forces

were calculated by converting the applied torque to tangential force by multiplying with outside

diameter and dividing the same by number of nodes on the side of the fixture of the shaft model.

To restrict the movement of the nodes in the radial direction at the end at which the force is

applied, the DOF in r-direction was arrested. The nodes are to be rotated along cylindrical

coordinate system so that the applied forces in nodal direction are tangential to the perimeter

of the shaft. No cantilever effect will be formed since the forces will deform the shaft about

axis by pure twisting.

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4. Finite element analysis results and discussion

4.1. Effect of winding angle and number of layers on torsional strength

The failure indices of the aluminum tube wound externally by four layers of carbon and

glass fiber/epoxy composite at different winding angles are shown in Fig.4.1. It can be seen

that 45 winding angle can withstand more torque than that for 90 in case of both, glass and

carbon fiber wound composite tube. Moreover, at a lower torsional load, the failure indices are

close to each other this is because the aluminum tube is still within the elastic limit. When the

failure index is one, the failure torque is 131 N m and 195 N m for aluminum tube wound

externally by four layers of glass and carbon fibers at winding angle of 45, respectively.

Fig. 4.1. Failure indices of aluminum tubes wound by four layers of carbon and glass

fibers/epoxy.

Similar results to those four layers were drawn for six layers of glass and carbon fibers

as shown in Fig. 4.2.

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Fig. 4.2. Failure indices of aluminum tubes wound by six layers of carbon and glass

fibers/epoxy

A hybrid shaft wound externally by carbon fiber/epoxy is stronger than the hybrid shaft

wound externally by glass fiber/epoxy and supports high torque capacity.

4.2. Effect of stacking sequence on torsional strength

The effect of stacking sequence on the failure indices and torsion capacity of a hybrid

shaft for both carbon and glass fibers are shown in Fig. 4.3.

Fig.4.3. Effects of change stacking sequence on the failure indices for hybrid shaft wound

externally by four layers of glass and carbon fiber/epoxy.

The torsion-failure index response is close to each other. Again the carbon fiber/epoxy

gave higher torque capacity than that for glass fiber at same index failure.

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4.3. Effect of hybridization on torsional strength

The effect of hybridization on the failure indices for aluminum tube wound externally by

four and six layers of 45 winding angle are shown in Figs. 4.4 and 4.5, respectively.

Fig. 4.4. Effect of hybridization on the failure indices for aluminum tube wound externally by

four layers of winding angle at 45

Fig. 4.5. Effect of hybridization on the failure indices for aluminum tube wound

externally by six layers of winding angle at 45

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It is clear that hybridization enhanced the torque capacity of a hybrid shaft in comparison

with the use of glass fiber alone on the outside of the aluminum tube. On the other hand, that

carbon fiber/epoxy composite still gives better performance than that for hybridization.

Fig. 4.6 shows the failure indices of the aluminum tube wound externally by [+45/-

45/90/90] laminate for different composite materials.

Fig. 4.6. Failure indices for aluminum tube wound externally by [+45/-45/90/90] for

different composite materials

At low level of loading the failure indices are close to each other. On the other hand, at

the high levels of loading the failure are controlled by the layers of carbon fiber. At failure

index equal one, the failure torques are 146 N m, 153 N m and 168 N m for [+45/-45/90/90]

glass, [(+45-/45)glass/(90/90)carbon] and [+45/_45/90/90]carbon, respectively.

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5. Comparison between the experimental and finite

element results

5.1. Torque versus angle of twist comparison

Torque versus angle of twist relation comparison for aluminum tube wound externally

by two layers of composite material at winding angle of 45 is shown in Fig. 5.1. Similar trends

were obtained for the finite element analysis results and the experimental results.

Fig. 5.1. Torque versus angle of twist comparison for aluminum tube wound externally by

[+45/-45] laminate for different composite materials

The finite element model has lower angle of twist than the experimental drive shaft for

same torque. At the failure point the maximum torsion capacities for carbon fiber are 74.32 N

m and 86.5 N m and for glass fiber 50.9 N m and 67 N m for experimental and finite element

analysis, respectively. These differences occur because in finite element analysis it is assumed

that the hybrid aluminum/composite drive shaft is homogenous in terms of dimensions,

properties and winding pattern. While, through the experimental test homogeneity is never

exactly the same throughout the positions in each hybrid shaft.

Fig. 5.2 shows torque versus angle of twist relation comparison for aluminum tube wound

externally by [+45/-45]2 laminate. The results obtained from finite element analysis and

experiments have the same trends. The failure point for carbon fiber the maximum torques is

157.52 N m and 195 N m, whereas for glass fiber is 126.2 N m and 137.2 N m for experimental

and finite element analysis respectively.

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Fig. 5.2. Torque-angle of twist comparison for aluminum tube wound externally by

[+45/-45]2 laminate at different composite materials.

Fig. 5.3. shows torque-angle of twist diagram comparison for aluminum tube wound

externally by [+45/-45]3 laminate. Again the trends of results are the same. At point of failure

the maximum torsion capacities for carbon fiber is 273.2 N m and 295 N m and for glass fiber

173.5 N m and 188 N m for experimental and finite element analysis respectively.

These differences are attributed to the fact that in the finite element analysis the hybrid

aluminum is assumed perfect in terms of dimensions and properties.

Fig. 5.3. Torque-angle of twist comparison for aluminum tube wound externally by [+45/-45]3 laminate for different composite materials.

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5.2. Comparison of maximum torque capacity

Comparison of maximum torsion capacities between the experimental and finite element

analysis for aluminum tube wound externally by glass fiber at different winding angle and

number of layers is shown in Fig. 5.4.

Fig. 5.4. Comparison of torsion capacities comparison between experimental and finite

element analysis for aluminum tube wound by glass fiber/epoxy composite.

Fig. 5.5 shows the comparison between the experiment and FEA results for aluminum

tube wound externally by carbon fiber at 90 and 45 for different number of layers,

respectively.

Fig. 5.5. Comparison of torsion capacities comparison between experimental and finite

element analysis for aluminum tube wound by carbon fiber/epoxy composite.

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The maximum torsion capacity of 273 N m was obtained experimentally for the hybrid

aluminum/composite drive shaft consists of aluminum tube wound externally by six layers

[45]3 of carbon fiber composite. The strength of material relations were used to calculate the

torsion capacity of the metallic shaft of the same size, the properties in Table 4 was used in

calculation. The result showed that the torsion capacity of metallic shaft is 293.71 N m and

weight reduction ratio is 43%.

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Conclusions

Finite element analysis was carried out for a hybrid aluminum/composite drive shaft to

predict the torsional strength. Five cases with different composite materials, stacking sequences

and numbers of layers were studied. The conclusions are summarized as follows:

1. As the number of layers are increased, the static torque capacities of the hybrid shaft

for both carbon and glass fiber composite materials also increases.

2. A hybrid aluminum/composite wound with 45 layers can withstand higher static

torsion compared to 90 in all cases.

3. Shaft being laminated with stacking sequence [90/+45/-45/90] and [+45/-45/90/90]

gave the same behaviour of torque-angle of twist relation.

4. A finite element study was carried out using ANSYS software to predict the static

torsion capacity including the elasto-plastic properties for aluminum tube and linear

elastic for composite materials. The comparisons between the experimental and

predicted results carried out using ANSYS software gave good agreement.

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References

1. S.A. Mutasher, Prediction of the torsional strength of the hybrid aluminum/composite

drive shaft, Materials and Design 30 (2009) Page: 215220.

2. D. G. Lee , H. S. Kim, J. W. Kim, J. K. Kim, Design and manufacture of an automotive

hybrid aluminum/composite drive shaft, Composite Structures 63 (2004) Page: 8799.

3. ASM Handbook, Volume 21, Composites, ASM International.

4. A. K. Kaw, Mechanics of Composite Materials, Second Edition, Taylor & Francis.