ACD504_Session_00_General.pdf

M. S. Ramaiah University of Applied Sciences

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Module Code: ACD504

Module Title: Aircraft Structures

Module Leaders:

Dr. Vinod K. [email protected]

Mr. Suman [email protected]

Mr. Shivakumar [email protected]


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Module Details

Course: M. Tech. in Aircraft Design

Department: Automotive & Aeronautical Engineering

Head of the Department: Dr. Srikari S.

([email protected])

Faculty: Engineering & Technology

Dean: Dr. H. K. Narahari ([email protected])


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Why this Module

The objectives of the course are to:

1. Explain the construction, working principles and functional requirements of aircraft

systems with respect to their performance

2. Convert the customer requirements to viable design specifications and evolve

conceptual design

3. Model, simulate, analyse and validate aircraft conceptual design to meet

operational requirements using commercially available tools

4. Demonstrate Critical, analytical, problem solving and research skills in the domain

of Aeronautical Engineering

5. Develop a career in Aeronautical Engineering

6. Practice Teamwork, lifelong learning and continuous improvement

The Module is being delivered to meet the highlighted objective of the course to

meet the course aim.


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Module Aim and Summary

The aim of this module is to give student basic understanding of the loads acting

on a fixed wing aircraft, structural configuration for supporting these loads, and

approach and methodology for designing structural assemblies and components.

Methodology utilising solution to structural problems using strength of material,

theory of elasticity and energy methods to design and analyse structural

components will be described to them. They will also be taught concepts of

dynamics and elastic stability as applicable to aircraft structures, aero-elastic

phenomena like aileron reversal, wing divergence and flutter. Design and

analysis of stability and dynamic characteristics of laminated composite plates

and shells will also be covered.


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Module Intended Learning Outcomes

After undergoing this module students will be able to:

1. Describe typical structural configurations, and the reasons thereof,

for various structural systems and assemblies of an aircraft, list the

sources of forces and means for calculating those

2. Relate the loading, static and dynamic, and the structural

configurations to identify potential modes of failure and identify

the approach to be taken for design

3. Analyse loads and structural layouts, and their interaction, to

assess the adequacy of design under the prescribed functional and

operational loads


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Module Intended Learning Outcomes

After undergoing this module students will be able to:

4. Coalesce knowledge of aerodynamic and structural design,

analytical ad numerical analysis methods to design, model,

simulate and analyse components/systems of an aircraft

structure

5. Identify the structural behaviour of parts in aircraft structure and

analyse it using simple analytical approaches

6. Use analytical and simulation means to develop design for

specified functional and operational requirements, assess various

options to come up with the most suitable solution


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Aircraft configuration and load paths: Structural layout, major assemblies and subassemblies,

structural concepts, design considerations

External and internal loads: Sources of loads, load factors, operational loads, ground loads

Design philosophy and methodology for structures and joints: Design requirements, regulation

based requirements, industry requirements, design for manufacturing, joint, lugs and fittings,

shear resistant beams, diagonal tension beams, validation and testing

Fatigue, Fracture and Damage tolerant design: Fatigue mechanism, properties and design

considerations, load history and damage accumulation, fatigue and failure of joints, corrosion

fatigue, Fracture mechanics and fracture mechanics approach to design, fatigue failure of joints

Deformation- kinematic modelling, including elastic instability, of beams, plates, and shells

Application of composite materials in aerospace structures

Analytical modelling of laminated composite plates and shells, Numerical solutions for buckling

and modal characteristics of composite plates and shells

Aero-elasticity phenomena in aircraft- Wing divergence and Flutter

Minimum- weight design criteria of aircraft structures

Aircraft configuration and load paths: Structural layout, major assemblies and subassemblies,

structural concepts, design considerations

External and internal loads: Sources of loads, load factors, operational loads, ground loads

Design philosophy and methodology for structures and joints: Design requirements, regulation

based requirements, industry requirements, design for manufacturing, joint, lugs and fittings,

shear resistant beams, diagonal tension beams, validation and testing

Fatigue, Fracture and Damage tolerant design: Fatigue mechanism, properties and design

considerations, load history and damage accumulation, fatigue and failure of joints, corrosion

fatigue, Fracture mechanics and fracture mechanics approach to design, fatigue failure of joints

Deformation- kinematic modelling, including elastic instability, of beams, plates, and shells

Application of composite materials in aerospace structures

Analytical modelling of laminated composite plates and shells, Numerical solutions for buckling

and modal characteristics of composite plates and shells

Aero-elasticity phenomena in aircraft- Wing divergence and Flutter

Minimum- weight design criteria of aircraft structures

Module Contents


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Module assessment will have two components:

Component - 1: 50% weight

Assignment (30% weight) followed by a presentation on the assignment

(10% weight) and a laboratory examination (10% weight).

A word processed assignment is to be submitted followed by a

presentation by the student.

In case there is no laboratory examination, the assignment (40% weight)

followed by a presentation on the assignment (10% weight) - applicable

only for those modules where it is not possible to have laboratory

examination.

Component - 2 : 50% weight

Written Examination (50% weight).

Method of Assessment (1)


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The assessment questions are set to test the learning outcomes. In each

component certain learning outcomes are assessed. The following table

illustrates the focus of learning outcome in each component assessed:

Both components will be moderated by a second examiner.

A student is required to score a minimum of 40% in each of the components

and an overall 40% for successful completion of a module and earning the

credits.

Method of Assessment (2)

Intended Learning Outcome 1 2 3 4 5 6

Component-1 (Assignment)

Component-2 (Examination)


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a. Essential Reading

1. Class Notes

2. T.H.G. Megson (2007) Aircraft structures for Engineering Students, 3rd Edition,

Elsevier Aerospace Engineering

3. E.F. Bruhn, (1973), Analysis and Design of Flight Vehicle Structures, Jacobs

Publication.

b. Recommended Reading

1. Bruce K. Donanldson (1993) Analysis of Aircraft Structures An Introduction,

McGraw-Hill International Edition

2. M. C. Niu (2005) Airframe Stress Analysis and Sizing, Technical Book Company

3. Dennis Howe (2004) Aircraft Loading and Structural Layout, Professional

Engineering Publishing, Lomdon

4. M.C. Niu (1988) Airframe Structural Design, Conmilit Press, Hong Kong

5. R. Stiles, J. Bertin, S. Brandt and R. Whitford (2004) Introduction to Aeronautics: A

Design Perspective, 2nd edition, AIAA Education Series

References


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Module Delivery Schedule (Theory)Number of Module Credits: 5

Session

No.Date

Time Day Topic Delivered

By

Additional

Activity

127-Apr-

2015

9.30 am

1:00 pm

Mon Basic Analytical Techniques VKB

228-Apr-

2015

9.30 am

1:00 pm

Tue Aircraft Loads VKB

329-Apr-

2015

9.30 am

1:00 pm

Wed Design for Fatigue SMLJ

430-Apr-

2015

9.30 am

1:00 pm

Thur Aircraft Structure Layout and

ConfigurationVKB

504-May-

2015

9.30 am

1:00 pm

Mon Design Philosophy and Regulation

RequirementsSHG

605-May-

2015

9.30 am

1:00 pm

Tue Fracture Mechanics SMLJ

706-May-

2015

9.30 am

1:00 pm

Wed Design of Joints SHG

807-May-

2015

9.30 am

1:00 pm

Thur Deformation Kinematics and Instability VKB

908-May-

2015

9.30 am

1:00 pm

Fri Composites VKB

10 11-May-

2015

9.30 am

1:00 pm

Mon Aeroelasticity VKB


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Session

No.Date Time Day Topic

Delivered

By

Additional

Activity

127-Apr-

2015

2:00 pm

5:30 pm

Mon Problem Solving using basic analytical

techniques Hand calculations VKB

228-Apr-

2015

2:00 pm

5:30 pm

Tue Problem Solving using basic analytical

techniques Hand calculations VKB

329-Apr-

2015

2:00 pm

5:30 pm

WedFatigue Analysis Component Stress Analysis SMLJ

430-Apr-

2015

2:00 pm

5:30 pm

ThurFatigue Analysis Fatigue Life Calculation SMLJ

504-May-

2015

2:00 pm

5:30 pm

Mon Modelling of Instabilities

SHG

605-May-

2015

2:00 pm

5:30 pm

Tue Modelling of InstabilitiesSHG

706-May-

2015

2:00 pm

5:30 pm

Wed Fracture Modelling of Cracks in Structures SMLJ

807-May-

2015

2:00 pm

5:30 pm

Thur Modelling of CompositesVKB

908-May-

2015

2:00 pm

5:30 pm

FriAnalysis of Composites VKB

10 11-May-

2015

2:00 pm

5:30 pm

MonPractice Session VKB, SMLJ, SHG

Module Delivery Schedule (Laboratory)


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Theory Sessions


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Session No. 1

Basic Analytical Techniques

At the end of this session students will be able to

Explain basic principles and concepts of Mechanics of

Materials

Classify, and analyse accordingly, structural components

based on their structural behaviour

Analyse structural components to assess their adequacy for

specific application without failure

Apply Theory of Elasticity approach for analysing structural

behaviour

Use energy Methods to solve structural problems


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Session No. 2

Aircraft Loads


Relate functional and operation requirements to respective

loads on aircraft structures

Explain cause and source of inertial loadings and relate

these to typical aricraft maneouvers

Explain the construction of V-n diagram and its significance

in structural design of aircraft

Explain the structural design philosophy and approach for

aircraft and importance of key load factors


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Session No. 3

Design for Fatigue


Identify the modes of failures

Describe the fatigue design criterion

Discuss the phenomenon of fatigue and testing

methodology


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Session No. 4

Structural Layout and Configurations


Explain major structural systems in an aircraft structure

based on their purpose and functioality

Based on the functional andoperational requirement,

describe the sources and types of loads acting on various

structural systems

Develop structural configuration and layout for structural

systems based on the expected loading

Describe methodology and considerations for sizing the

components


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Session No. 5

Design Philosophy and Regulation Requirements


Describe design philosophy and methodology for structures

and joints

Explain design requirements as per regulation based

requirements

Explain design requirements as per industry based

requirements

Explain design philosophy for manufacturing


Describe design philosophy and methodology for structures

and joints

Explain design requirements as per regulation based

requirements

Explain design requirements as per industry based

requirements

Explain design philosophy for manufacturing


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Session No. 6

Linear Elastic Fracture Mechanics


Discuss the importance of fracture mechanics in design

Compute Stress Intensity Factor for different modes of

fracture

Estimate energy release rate for brittle fracture

Compute the fatigue life and rate of crack propagation


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Session No. 7

Design of Joints


Analyse structural elements such as joints , lugs and fittings

and their load interaction

Analyse shear resistant beam structures and their load

interaction for adequacy of design

Analyse diagonal tension beam structure and their load

interaction for adequacy of design


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Session No. 8

Instability of Plates and Shells


Explain the idealisation of thin plates and shells resulting

kinematic behaviour

Identify geometric configuration and and loading

conditions for instability of such thin structural elements

Roughly estimate load carrying capability of such thin

structural elements


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Session No. 9

Composites

Explain the basic construction and mechanical behaviour of

composite materials

Demonstrate practical understanding of orthotropic

material properties

Describe and extimate macromechanical properties of a

lamina

Estimate tensile and compressive strength of lamina and

check for failure mode

Demonstrate understanding of classical laminate theory

and calculate properties of a laminate

At the end of the session students will be able to


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Session No. 10

Aeroelasticity


Explain Aeroelastic phenomena and physical processes

driving it

Explain the interaction of elasticity, aerodynamics and

structural dynamics in aeroelastic problems

Understand the phenomenology of aero/structural

interaction

Use simple mathematical models to estimate limiting

conditions from aeroelastic considerations


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Laboratory Sessions


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Session No. 1 & 2

Basic Analysitical Techniques


Analyse component level designs for adequacy under

simplified loading using

Basic mechanics approach

Theory of elasticity approach

Energy method approach

Develop idealised models of some typical complex

structures for first level of analysis

In this session, simple component level problems, like bending

and torsion of thin walled beams, analysis of idealised

strucure will be solved using basic mechanics approach.

some typical problems like bending of beams will be solved

using energy methods


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Session No. 3

Fatigue Life Estimation

At the end of this session, a student will be able to

Perform fatigue life analysis on stiffened panels and shafts using ANSYS

software

Perform fatigue analysis simple components with hand calculations and

validate using ANSYS software


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Session No. 4

Fatigue Life Estimation


Perform crack growth analysis for different shapes of cracks using ANSYS

software

Perform crack analysis to obtain Stress Intensity Factor using ANSYS software

and validate the same using hand calculations


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Session No. 5

Modelling of Instabilities


Perform the loads acting on the lugs and fittings with hand

calculation and validate using the ANSYS software

Perform and calculate the loads acting on the simplified

wing section with hand calculation and validate using the

ANSYS software


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Session No. 6

Modelling of Instabilities


Perform and calculate the loads acting on the fuselage with

hand calculation and validate using the ANSYS software

Analyse the structure such as diagonal tension beams and

their load interaction using ANSYS software

Analyse the buckling of beams and their load interaction

using Ansys software


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Session No. 7

Selection of Materials and Manufacturing using CES


Describe different categories of aircraft and turbomachinery components

Evaluate properties of materials for different components

Explain classification of materials and their properties

Analyse factors influencing selection of materials


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Session No. 8

Modelling of Composites


Define a lamina and its properties to be used in a finite

element model

Construct a component level model using prescribed layup

for a laminate

Develop a mathematical model for determining laminate

properties for given layup sequence

Step by step modelling of composite material in ANSYS will be

explained to the students. Material definition for lamina

and creating a laminate will be described.


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Session No. 9

Analysis of Composites


Perform Finite Element Analysis for composite components

of simple geometries

Post process the results to understand and analyse the

results at component and lamina level

Use mathematical model to design laminates for desired

properties

Components of simple geometric shapes and composite

material will be modelled and their respose with different

layups will be studied. Use of MATLAB for calculating

laminate property will be described.


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This session will be used by the students to practice problem solving,

analysis and mathematical modelling skills they have acquired in the

laboratory sessions

Session No. 10

Practice Session

ACD504_Session_00_General.pdf

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