Structural Design option - MSc in Aerospace Vehicle Design

To introduce you to the composite materials, manufacturing techniques and analysis methods for the design of aerospace composite structures.

• Introduction; Types of composite materials, especially FRP composites.
• Overview of composites manufacturing techniques.
• Micromechanics and macro mechanics for stiffness and strength analysis of a FRP ply; Macro mechanics, constitutive equation, stiffness and strength analysis of a FRP laminate; Thermal and moisture residual stresses in a FRP laminate.
• Stress analysis of an open section FRP composite structure subjected to various loadings.
• Stress analysis of a closed section FRP composite structure subjected to various loadings.
• Design guidelines and examples for composite structure design and analysis.
• Computer programmes for laminate stress, buckling of laminate and stiffened skin.

The classroom assignment on composite manufacturing techniques will take place towards the end of this module. The date and time will be confirmed by the tutor. The assignment is a one hour written paper that will take place in the classroom under exam conditions. This assignment is formally assessed and is worth 25% of the marks available for this module.

To provide you with an understanding of the theories of Fatigue and Fracture Mechanics and show how these structural concepts are applied to the design and testing of aircraft structures and Airworthiness Certification.

• Design awareness: Philosophies of design against fatigue and design for damage tolerance: i.e. safe-life, fail-safe and damage tolerance.
• Fatigue analysis: Traditional S-N curve approach: calculation of crack initiation life; mean stress effect, notch effect; Miner’s cumulative damage rule for variable amplitude loads.
• Aircraft fatigue loads: Typical aircraft load spectra for use in the laboratory and computer simulation.
• Fracture Mechanics: Basic Theory of Linear Elastic Fracture Mechanics (LEFM): Stress Intensity Factor, fracture toughness, strain energy release rate; plane stress and plane strain, crack tip plastic zone; residual strength; prediction of fatigue crack growth. Numerical techniques for crack prediction and analysis.
• Damage Tolerance: Damage tolerant design methods and technologies for composites and metals. Fatigue monitoring in flight/service and structural health monitoring. Inspection methods. CAA and FAA Regulations and their relationship to Airworthiness Certification Material selection.

To ensure that while you design your structure they are aware of the constraint imposed by manufacturing and operational considerations.

The influence of designing for maintainability will have a considerable effect on the design of both the structure and aircraft systems and a considerable effect on the life cycle cost of the vehicle. The taught material will have immediate practical application to the Group Design Project.

• Metallic and Non-metallic manufacturing processes.
• Material and Manufacturing process selection with CES Edupack.
• Wing configuration and manufacture.
• Assembly and production processes.
• Maintainability and accessibility.
• Design for Assembly and Maintainability methods.

To introduce you to the techniques of detail stressing as practised in the aerospace industry.

• The structural function of aircraft components. Definition of Limit, Proof and Ultimate loads and Factors for Civil and Military aircraft
• Basic formulas for stress analysis. Stress strain curves for metallic materials. Material equivalents. Concept of Reserve Factors (RF) and Margins of Safety (MS)
• Material data. Design guidelines for mechanically fastened joints. Lugs. Strength of bolted/riveted joints. Usage of approved aerospace components
• Structures under bending and compression. Euler buckling, flange buckling, inter-rivet buckling. Buckling of struts and plates. Shear buckling of webs
• Generalised stress strain curves
• Plastic bending and form factors
• Rivet and bolt group analysis
• Analysis of thin walled structures
• Preparation of a detailed Stressing Report and Reserve Factor summary tables for a classroom exercise to be completed during this module.

• Apply the principals and techniques in stress analysis and airworthiness requirements to size basic aircraft structural components.
• Evaluate the strength of a component and determine its ability to support an applied load.
• Compare, propose and select metallic materials suitable for use in aircraft structures.
• Acquire transferable skills to allow effective communication with company stress engineers.

To provide you with both an introduction to the theory underpinning finite element analysis (FEA) and hands on experience using the well-established FEA package.

• Background to Finite Element Methods (FEM) and its application
• ​Overview of element discretisation, FEA method, pre-processing, solution and post-processing, basic terminology, range of applications.
• Introduction to concepts of constitutive equations for linear elasticity.
• Introduction to concepts of nodal displacement, element shape functions for 1D and 2D linear-elastic structures.
• Introduction of FEA matrices, equations and critical steps to an FEA solution.
• Presentation of commercial FEA software packages.
• Presentation of FEA for mechanical analysis using various element types: bars, beams, 2D, 3D, shell elements.
• Presentation of FEA for heat transfer analysis, equivalence with other field problems, convergence issue, boundary conditions, model creation and solution.
• Presentation of CAD model, meshing, symmetry, model development, implementation of force boundary conditions, solution, and post processor analysis.
• Advanced FEA analysis: geometric non-linearity, material non-linearity, contact problems, dynamic problems, and explicit solution.
• Applications of FEA to enhanced mechanical designs: Optimisation
• Case studies on metallic and composite structures

1. Recognise finite element analysis (FEA) methodology and uses by comparing principles, assumptions and case studies to state-of-the-art.
2. Recognise and examine the limitations associated with the use of FEA in actual applications.
3. Demonstrate an approach for solving a range of actual problems.
4. Evaluate considerations for applying FEA to component modelling.
5. Critically assess the results obtained from FEA by comparing FEA solutions from fundamental matrix operations, constitutive equations and a commercial software.

To introduce you to the process of aircraft conceptual design and support structural layout work, were required, through participation on the Group Design Project.

• Aircraft project design process
• Drag and weight prediction:  Drag sources, polar, estimation, weight prediction methods. Layout aspects:  wing; power plant; landing gear; fuselage
• Simple tail plane and fin layout
• Overall project synthesis and case study of aircraft
• Structural requirements, - strength, stiffness and serviceability
• Analysis of requirements, sources of load and reference datum lines
• Role of structural members - main plane, stabilisers, auxiliary surfaces, fuselage
• Analysis and sizing methods - elementary theories
• Departures from elementary theories - constraint effects, cut outs, buckling.

To provide you with knowledge of all the main loading cases including those encountered on the ground, in the air and those induced by the environment. This is the initial module on the MSc course, its contents are fundamental and the taught material will have immediate practical application to the Group Design Project.(GDP).

• Standard requirements, their application, interpretation and limitations.
• Flight loading cases: symmetric manoeuvres, pitching acceleration, gust effects, asymmetric manoeuvres, roll and yaw.
• Balance equations: rigid airframe response, control movements and forces.
• Ground loading cases: Airload distributions.
• Structural design data: Inertia relief and effect on shear force, bending moment and torque diagrams.
• Factors: load factors, their basis and restrictions. 

To provide you with an introduction to the aircraft airworthiness as well as knowledge of reliability assessment methods, safety assessment methods, and certification issues associated with the design of Aircraft Systems (including weapon systems and survivability). To familiarise you with current air accidents investigation techniques and processes.

• Airworthiness
• Reliability
• Reliability requirements – JAR25-AC.1309
• Probabilities of failure, MTBF, MTBR, etc.
• Reliability models – series and parallel systems, common mode failures
• Safety Assessment Analysis Methods
• Failure Modes and Effects Analysis (FMEA)
• Fault Tree Analysis (FTA)
• Reliability predictions
• Common Cause Analysis (CCA)
• System Safety Assessment Process
• Functional Hazard Analysis (FHA)
• Preliminary System Safety Assessment (PSSA)
• Air Accidents Investigation

To provide you with a fundamental understanding of the buckling of thin walled structures and the ability to calculate the buckling load of a component.

• The buckling of thin plates and thin-walled sections using the Rayleigh-Ritz method of analysis. Alternative methods of buckling analysis.
• Timoshenko's method for columns.
• Exact solution of differential equations.
• Approximate solution of differential equations, Finite difference method, Galerkins method, Theoretical post-buckling analysis of plates in compression.
• The concept of effective width for thin plates.
• The behaviour of imperfect plates, Torsional-Flexural buckling of thin-walled open section columns.
• The buckling behaviour and failure of stiffened panels, crippling of thin-walled sections, stiffened shear webs.
• This module has additional accompanying tutorials and workshops as required, plus a laboratory demonstration of the compressive buckling failure modes of struts and stiffened panels.

To introduce you to the importance of aeroelastic phenomena, basics of aeroelasticity and analysis methods for the design of aircraft structures.

• Introduction (historical review, aeroelastic phenomena and design requirements);
• Structural and aerodynamic stiffness;
• Static aeroelasticity: torsional divergence, control effectiveness and reversal;
• Structural vibration and modal analysis;
• Aerodynamic loads on an oscillating lifting surface;
• Characteristics of flutter and important design parameters;
• Methods for aeroelastic analysis (divergence and flutter speed prediction);
• Gust response of rigid and flexible airframes;
• This module has additional accompanying tutorials and computer workshops as required.

On successful completion of this module you should be able to:
1. Recognise the importance of aeroelastic phenomena and design requirements.
2. Explain the theory of aeroelasticity including static and dynamic aeroelastic problems.
3. Illustrate the approach for evaluating divergence and flutter speed of aircraft structures.
4. Demonstrate the application of knowledge to the practical design aspects of aerospace structures using available PC based computer programs.
5. Apply your knowledge and skills to estimate the flutter speed of the Group Design Project aircraft.

To introduce you to system engineering concepts, system lifecycle models and system design processes and methods.

• Introduction to Systems.
• Life Cycle Models.
• System Requirements.
• Systems Design.
• System Integration, Verification and Validation.

The aim of this module is to provide you with the knowledge of the Atmosphere and of the basic aerodynamic characteristics of a conventional aircraft in the context of its mechanics of flight.

• Atmosphere Mechanics: structure of the atmosphere, international standard atmosphere model, design atmospheres.
• Air Data Systems: Pitot-static systems. Altitude, airspeed and Mach number. Air temperature and airflow direction detectors.
• Basic flight mechanics: forces acting on the aircraft, balance and trim. The forces of lift and drag and their characteristic dependencies.
• Powerplant thrust characteristics: effects of weight, altitude, temperature and Mach number.
• Aircraft axis systems.
• The aerodynamic aspects of the outline design process of a transport aircraft.
This module has additional accompanying flying laboratory tutorials in the Jetstream Aircraft. See Flight Experimental Methods (FXM).

To facilitate you in gaining fundamental knowledge of the theory of conventional fixed wing aircraft performance to a level suitable for an aerospace vehicle designer. In particular, to provide you with the ability to apply aircraft performance theory, practically in the context of aerospace vehicle design.

• Introduction to Aircraft Performance
• Aircraft Cruising Performance
• Aircraft Climb and Descent Performance
• Aircraft Take-off and Landing Performance
• Aircraft Manoeuvre Performance
• Flight Path Performance Estimation
• Aircraft Performance Measurement

A classroom exercise will be completed during this module. Solutions will be collected in by the tutor at the end of the module.

To introduce you to the engine and aircraft-related aspects of the propulsion system, with the primary emphasis being placed on gas turbine engines.

• Simple gas turbine theory illustrating the effect of gas turbine cycle parameters.
• Relations between specific fuel consumption, specific range and thermal and overall efficiencies for various engine types including turbo-props.
• Choice of cycle for various applications.
• Brief assessment of engine size required and engine / airframe matching including the importance of the airworthiness performance requirements.
• Impact of engine rating on engine / airframe matching.
• Impact on engine installation of various systems required by the aircraft.

To provide an introduction to the fundamentals of aircraft stability and control.

• Stability, control and handling qualities relationships.
• Aircraft aerodynamic controls.
• Static equilibrium and trim.
• Longitudinal static stability, trim, pitching moment equation, static margins.
• Lateral-directional static stability.
• Introduction to dynamic stability, first and second order responses.
• Equations of motion and modal characteristics.

On successful completion of this module you will be able to:

• Describe the concepts of: trim, stability and control.
• Describe methods of providing static stability for a conventional aircraft.
• Describe the modes of motion of a conventional aircraft.

The aim of this module is to introduce you to the role of Computer Aided Design technologies in a modern Integrated Product Development process and provide hands-on experience of CAD using the CATIA v5 software.

• Introduction to Integrated Product Development (IPD) for aircraft design
• Overview of Computer Aided Design, Manufacture and Engineering tools and their role in IPD
• Introduction to CAD modelling techniques:
o Solid Modelling
o Assembly Modelling
o Parametric Design
o Surface Modelling
o Drafting
• Hands on CATIA exercises using CATIA v5 including fuselage and wing design exercises
• Using CATIA for the Group Design Project.

To expand the your knowledge of airframe systems, their role, design and integration. In particular, to provide you with an appreciation of the considerations necessary and methods used when selecting aircraft power systems and the effect of systems on the aircraft as a whole.

• Introduction to airframe systems
• Systems design philosophy and safety
• Aircraft secondary power systems
• Aircraft pneumatics power systems
• Aircraft hydraulics power systems
• Aircraft electrical power systems
• Flight control power systems
• Aircraft environmental control
• Aircraft icing and ice protection systems
• Aviation fuels and aircraft fuel systems
• Engine off-take effects
• Fuel penalties of systems
• Advanced and possible future airframe systems

To provide you with flights in the Flying Laboratory in support of the lecture course in Aircraft Aerodynamics, Aircraft Performance, and Aircraft Stability and Control. These flights are key for students who are from a non-aeronautical background, and will also serve as a refresher for the remaining students.

• Measurement of aircraft drag and effect of flap (AD, SD & ASD).
• Aircraft longitudinal static stability (AD & SD)
• Avionic demonstration and inertial system accuracy (ASD)
• Dynamic stability modes (AD, SD & ASD)

• Describe the flight test techniques used to measure simple aerodynamic parameters and assess navigation systems.
• Describe the dynamic stability modes of a conventional aircraft.

To provide you with a general understanding of the design of landing gear and the associated systems and the associated challenges of integrating them into an airframe. The module also aims to highlight the implications that the design of the landing gear has on the aircraft layout and structure.

• Landing gear layout (Skids, flying boats, tricycle, bicycle, multi-wheel etc.)
• Ground flotation (Aircraft Classification Number [ACN] & Pavement Classification Number [PCN])
• Tyres (Failure modes and causes and wear. Radial vs. Cross-ply)
• Wheels (Bowl type vs. ‘A’ type)
• Brakes
• Struts (Cantilever vs. Trailing arm)
• Loads (Ground loads and airframe attachment loads)
• Shock Absorbers (Single acting and double acting. Compression curves)
• Retraction
• Ground manoeuvring (Steering)

• Evaluate the various landing gear layout schemes and assess which is best for any particular aircraft layout.
• Demonstrate a systematic understanding of the procedures and steps for positioning the landing gear on the aircraft (longitudinally and laterally).
• Critique historic landing gear designs and understand why various design decisions have been made and analyse their impacts on the aircraft.