Volume 9, Issue 1, January 2024 International Journal of Innovative Science and Research Technology

ISSN No:-2456-2165

Strength and Weight Optimization of Passenger

Aircraft Fuselage Skin
Atharva Salunkhe1; Chetan Patil1; Harshvardhan Deshmukh1; Yash Shinde1; Krishna.B. Jadhav1*
1
Department of Aerospace Engineering, MIT Art Design and Technology University, Pune 412201, India

Abstract:- Since most of the crucial components, and high stress. Among these materials, hybrid composites,
including the front, rear, and wings, are attached to the specifically the amalgamation of carbon fiber and glass fiber
central fuselage, it plays a significant influence in the reinforced with advanced epoxy resins, have emerged as
design of aircraft fuselages, leading to increased payload promising avenues for enhancing the structural integrity and
and improved performance. So, the load applied to the performance of aircraft fuselages.
part is transferred to the central fuselage part. The
primary objective of our study is to optimize the fuselage This study is geared towards exploring and optimizing
skin to withstand varying loads, with a particular focus the structural composition of aircraft fuselages by leveraging
on the central fuselage part where the load is the interdependent properties of hybrid composites. Through
transferred. This central fuselage plays a pivotal role in the synergistic combination of the superior strength and
the overall weight distribution of the aircraft. To achieve stiffness of carbon fiber with the impact resistance and cost-
weight reduction, we employ material optimization effectiveness of glass fiber, this research endeavors to create
techniques, specifically comparing aluminium alloy with a material composition that transcends the limitations of
hybrid composite materials. individual constituents. The incorporation of high-
performance epoxy resins further bolsters the structural
Material optimization involves a comprehensive characteristics, imparting resilience and stability under
comparison between aluminium alloy and hybrid diverse operating conditions.
composite materials, wherein composite laminates,
comprising carbon fiber, glass fiber, and Hexply 8552, The significance of this investigation lies in its
are applied over the fuselage skin. This approach allows potential to yield a fuselage structure that not only meets but
us to analyze both the physical and structural properties exceeds the rigorous demands of the aviation industry. The
of the fuselage. pursuit of an optimized fuselage design using hybrid
composites addresses multifaceted objectives, including
Various structural analyses, including Shear Test, weight reduction, enhanced fuel efficiency, improved
Bending Test, Fatigue Test, Tensile Test, and mechanical properties, and elevated safety standards, all
Compression Test, have been meticulously conducted while concurrently upholding passenger comfort and
using ANSYS WORKBENCH Software. Boundary operational economy.
conditions are established according to specific
requirements. The results unequivocally demonstrate II. LITERATURE REVIEW
that the hybrid composite material exhibits superior
properties compared to conventional aluminium alloy. Penn State Harrisburg, PA, USA, Athreya Nagesh*,
This includes enhanced performance and achieved Ola Rashwan, Maamoun Abu-Ayyad, Published November
material optimization, ultimately impacting the total 2018,[1] "Composite Aeroplane Fuselage Optimisation for
weight of the aircraft. Optimal Structural Integrity" Rather than using AL alloys
for the fuselage skin, this study used finite element analysis
Keywords:- Material Optimization, Aluminium Alloy, to find the optimal composite laminate combination..R
Carbon Fibre, Glass Fibre, Hexply 8552, Hybrid Composite Sreenivasa, C.S. Venkatesha, Jain Institute of Technology,
Materials. Karnataka, India,[2] “Study The Effect Of Crack on Aircraft
Fuselage Skin Panel Under Fatigue Loading Conditions”
I. INTRODUCTION .This article investigates the effect of fatigue loading
conditions on fuselage skin panel cracks. According to the
In the contemporary landscape of aviation, there has fatigue analysis results, the uncracked model has a life under
been substantial progress in the design and construction of the specified parameters since it can sustain load cycles. [3]
aircraft, with a primary focus on achieving an optimal K Vamssi Venugopal, I. R. K. Raju, “Design and
balance between performance, durability, and fuel Optimization of Aircraft Fuselage under Dynamic Response
efficiency. The aircraft fuselage, serving as the fundamental by Finite Element Analysis” This study presents some
framework of aerial transportation, plays a critical role in essential components of the design and analysis of airplane
influencing these key factors. In recent times, the structures. The selection of materials, the structure's design,
introduction of composite materials has brought about a the evaluation of loads, and the influence of dynamic loads
paradigm shift in aircraft design, offering exceptional are some of these essential components. It has been
strength-to-weight ratios and resilience to fatigue, corrosion, observed that metal weighs more than composite fiber. After

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Volume 9, Issue 1, January 2024 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
material optimization, the construction is subjected to both The dimensions of the fuselage are as follows:
static and dynamic load conditions.[4] Y Santosh, Prashanth
Bhatti, “Structural and Modal Analysis of Fuselage” the Table 1: Dimensions of fuselage model
process of conceptually designing an airplane's fuselage Parameter Value (mm)
structure using CAD software. These findings demonstrate Outer Diameter 5972
the superiority of the novel construction over the T-shaped Inner Diameter 5970
cross section.[5] Sowmya R, Sreenivasa R, Kallesh SS, Fuselage Length 7482
“Design Optimization If Airframe in Aircraft Fuselage Window Width – 270
Structure under Static Loading Conditions” The current Length - 518
article explains how to identify which airframe designs can
withstand static loading circumstances with the least amount B. Meshing
of deflection by optimising the design of fuselage Following the design phase, meshing was conducted in
components that include airframes. To obtain correct results, Ansys, a critical step in Finite Element Analysis (FEA)
each model's boundary conditions are adjusted. 2024-T351 simulation. Meshing involves transforming amorphous
Aluminum Alloy is used in the fuselage structure. After shapes into discrete "elements" or well-defined volumes.
comparing the optimized models, it is found that Case 6 has This step is essential for accurate simulation results. The
less produced stress (118 Mpa) while Case 7's optimised mesh is composed of elements with nodes, the number and
fuselage model has a 2.5mm deflection.[6] Mukhopadhyay, distribution of which depend on the type of element chosen.
Vivek Sorokach, Michael R, 2015“Utilization of Advanced Nodes represent coordinates in space and define the
Composites in Fuselage Structures of Commercial Aircraft” geometry's shape, playing a pivotal role in the accuracy of
Through a study, the knowledge and technologies needed to the FEA simulation.
make it possible to employ advanced composites in the
future to produce large transport aircraft fuselage structures
were identified.

METHODOLOGY

The project strives to optimize fuselage skin through

composite materials, utilizing Ansys software. The fuselage
model, referencing the Airbus A-350, was constructed in the
Discovery module of Ansys. Subsequently, the composite
skin design is being developed in the ACP module of Ansys,
followed by the execution of various structural tests within
the Ansys platform. Fig. 2: Meshed model of fuselage

C. Selection of materials
A. Fuselage model
The 3D model of the fuselage was created using the After meshing, selecting the appropriate materials for
the fuselage skin becomes a critical task, considering all
Discovery module of Ansys. This product simulation
parameters affecting the aircraft's performance. The chosen
software enables efficient model preparation and the
exploration of design variations with real-time interactivity. materials for this purpose include Carbon fiber, Glass fiber,
The design process was informed by the Airbus A-350 as a and HexPly 8552 Epoxy matrix (resin). Carbon fiber,
reference, chosen for its remarkable fuel efficiency and primarily composed of carbon atoms, is renowned for its
exceptional comfort levels. Ansys Discovery 3D played a exceptional strength, flexibility, and high tensile strength.
pivotal role in rapidly generating models for simulation and Additionally, it offers high stiffness and chemical resistance.
Glass fiber, on the other hand, is widely used in Polymeric
experimenting with various design concepts.
Matrix Composites (PMCs) due to its excellent tensile
strength and stiffness properties. By carefully considering
these material characteristics, we aim to ensure optimal
performance and durability of the fuselage skin.Glass fibers
offer cost-effectiveness, chemical resistance, high tensile
strength, and superior insulation. The high-performance
epoxy matrix HexPly 8552 is specifically designed for
critical use in major aircraft structures, ensuring durability
and optimal performance. For a variety of uses, it
demonstrates good damage tolerance and impact resistance.
HexPly 8552 is a resilient epoxy resin system, amine-cured,
Fig. 1: 3D Model of Fuselage and available with woven or unidirectional carbon or glass
fiber options.

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Volume 9, Issue 1, January 2024 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
Table 2: Properties of composites
Sr. No. Properties Carbon fiber Glass fiber HexPly 8552
(395 GPa) (S Glass) Epoxy matrix
1 Density (kg/m3) 1750 1857 1301
2 Thermal Conductivity(W/m.k) 6 0.04 low
3 Tensile Strength (MPa) 3000-7000 2000-4000 60-120
4 Young's Modulus (GPa) 230 70-80 2.5-5
5 Comp. Strength (MPa) 3000 3000-4000 80-150
6 Flexural Strength (MPa) 3000-7000 1000-2000 80-150

D. Design of composite fuselage skin

The fuselage skin design was accomplished using the of the fuselage in opposite directions to the center. The
ACP module of Ansys. Ansys Composite PrepPost (ACP) is applied force had a magnitude of 10000 N.
an integrated tool within the Workbench platform
specifically designed for modeling composite laminates. C. Compression Test
ACP facilitates the precise definition and selection of In a compression test, a mechanical device is utilized
material data, allowing for accurate specification of stacking to assess how a product or material responds to applied
sequences throughout the entire structure during the pre- forces. In this context, the fuselage skin serves as the test
processing phase. specimen. The test is conducted by applying forces of equal
magnitude at the ends of the fuselage in the same direction
towards the center. The applied force has a magnitude of
10000 N.

D. Bending Test
This rapid and cost-effective qualitative test assesses
the ductility, bend strength, fracture strength, and resistance
to fracture of a material. The test involves fixing both ends
of the fuselage and applying loads to the top surface. The
magnitude of the applied load is 10000 N.

Fig. 3: Composition and fibre orientation E. Shear Test

Shear testing involves subjecting a test sample to stress
III. STRUCTURAL TESTS AND BOUNDARY to induce sliding failure along a plane parallel to the applied
forces. Understanding how a material responds to forces
CONDITIONS
acting parallel to its surface is crucial for assessing structural
integrity. In the case of fuselage testing, one end is fixed,
Various static structural tests were conducted in Ansys
and a tangential load is applied to the skin in the opposite
software to analyze stress, strain, and deformation under
different loading scenarios. This process aids in identifying direction. The magnitude of the applied load is 10000 N.
weak points with low strength and durability during the
design stage. Initial tests were performed on conventional IV. RESULTS AND DISCUSSIONS
materials, followed by evaluations on our designed
composite material. Following the design of the composite fuselage skin, a
comprehensive set of static structural analyses, including
The tests which have been performed are: Fatigue, Compressive, Tensile, Shear, and Bending tests,
were conducted. For each test, two key parameters, namely
A. Fatigue Test Stress and Strain, were considered. This approach facilitates
Fatigue tests were conducted to determine the number a meaningful comparison between the performance of the
of load cycles until failure and assess the material's stiffness composite fuselage and the conventional Aluminium alloy
and strength degradation under repeated loading. The tests fuselage. The analysis aims to provide insights into the
involved applying pressure at the top and bottom of the structural behavior and performance differences between the
two materials under various loading conditions.
fuselage in an outward orientation, with fixed supports at the
right and left ends. The magnitude of the applied pressure
was 20000 Pa. A. Fatigue test

B. Tensile Test  Life cycle

Tensile testing is a destructive method employed to  The life cycle of the Al alloy fuselage is 10^8.
measure the ductility, yield strength, and tensile strength of  The fuselage of the hybrid composite has 10^10 life
metallic materials. This technique involves applying force to cycles.
break a composite or plastic specimen and observing the
elongation before failure. In this study, tensile testing was
performed by applying forces of equal magnitude at the ends

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Volume 9, Issue 1, January 2024 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165

Fig. 7: Al alloy fuselage

Fig. 4: Life cycle of the fuselage in Fatigue test

 Stress
 In an alloy fuselage, the highest equivalent stress created
during a fatigue test is 2.8*10^6 Pa.
 In a fatigue test, the hybrid composite fuselage's
maximum equivalent stress was 4.1*10^6 Pa.

Fig. 8: Composite fuselage

B. Bending Test

 Stress
 In a bending test, the highest equivalent stress generated
in an aluminum alloy fuselage is 2.9*10^5 Pa.
 In a bending test, the hybrid composite fuselage's
maximum equivalent stress is 3.5*10^5 Pa.

Fig. 5: Al alloy fuselage

Fig. 9: Al alloy Fuselage

Fig. 6: Composite fuselage

 Strain
 The highest strain that the fatigue test can create in an
aluminium alloy fuselage is 0.00048.
 5.5*10^-5 is the strain that the fatigue test of the hybrid
Fig. 10: Composite Fuselage
composite fuselage causes.

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Volume 9, Issue 1, January 2024 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
 Strain
 In a bending test, the Al alloy fuselage experiences a
maximum strain of 3.4*10^-5.
 The hybrid composite fuselage experiences a maximum
strain of 4.9*10^-6 during the bending test.

Fig. 14: Composite Fuselage

 Strain
 The Al alloy fuselage experiences a maximum strain of
1.3*10^-6 during the compression test.
Fig. 11: Al Alloy Fuselage  2.2*10^-7 is the maximum strain that a compression test
on a hybrid composite fuselage may create.

Fig. 12: Composite Fuselage

Fig. 15: Al alloy Fuselage
C. Compression Test

 Stress
 In a compression test, the maximum equivalent stress
generated in the Al alloy fuselage is 15413 Pa.
 In a compression test, the hybrid composite fuselage had
a maximum equivalent stress of 20897 Pa.

Fig. 16: Composite Fuselage

D. Shear Test

 Stress
 The highest comparable stress generated in the Al alloy
fuselage during the shear test is 1.26*10^5 Pa.
Fig. 13: AL Alloy Fuselage  In a shear test, the hybrid composite fuselage's maximum
equivalent stress is 1.28*10^5 Pa.

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Volume 9, Issue 1, January 2024 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
E. Tensile Test

 Stress
 In an Al alloy fuselage, the maximum equivalent stress
produced during a tensile test is 15413 Pa.
 The hybrid composite fuselage's highest equivalent
stress during the tensile test was 20897 Pa.

Fig. 17: AL Alloy Fuselage

Fig. 21: Al Alloy Fuselage

Fig. 18: Composite Fuselage

 Strain
 In a shear test, the highest strain caused in the Al alloy
fuselage is 1.6*10^-5.
 The hybrid composite fuselage experiences a maximum
strain of 1.7*10^-6 during the shear test.

Fig. 22: Composite Fuselage

 Strain
 The Al alloy fuselage experiences a maximum strain of
1.3*10^-6 during the Tensile Test.
 2.2*10^-7 is the maximum strain that can be created in
the hybrid composite fuselage during a tensile test.

Fig. 19: Al alloy Fuselage

Fig. 23: Al Alloy Fuselage

Fig. 20: Composite Fuselage

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Volume 9, Issue 1, January 2024 International Journal of Innovative Science and Research Technology
ISSN No:-2456-2165
[3]. Bauman Moscow State Technical University
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[10]. Osvaldo M. Querin, University of Leeds, School of
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