Aims

The aims of the course are to:

• cover the basic principles of practical design of typical engineering structures, with applications across a range of commonly-used structural materials.
• establish links between the theory of structures, taught in the Part I courses IA Structural Mechanics and IB Structures, and the properties of materials as covered in courses on Materials and Engineering Applications.
• study what differing approaches to design are appropriate for structures in different materials.
• develop a design methodology that provides a firm basis for the structures courses taught in Part IIA and for the more advanced courses in the fourth year.

Objectives

As specific objectives, by the end of the course students should be able to:

• have developed a good understanding of the structural forms appropriate in the various materials.
• be aware of the likely critical factors (requirements, properties, behaviour) for design in the different materials.
• be able to make sensible initial layout and sizing choices for simple structures in the various materials.
• be able to carry out design calculations for basic structural elements in the various materials.
• be aware of what design approaches will be appropriate, and what calculations necessary, for more complex structures in the various materials.
• appreciate the influence of risk, and variability of loading and material properties, on structural design and calculations.

Content

The implications of the general principles of structural mechanics – equilibrium, compatibility, constitutive laws, and stability – are investigated for different materials.  This leads to discussion of typical structural forms in the various materials, the reasons for adopting them, and appropriate methods of construction.   The significant types of structural behaviour, and therefore the most useful methods of analysis and calculation, are investigated for the different material types.   A basic aim is to establish means of making reasonable preliminary decisions about structural form and layout, and initial sizing of members, before detailed calculation need begin.

Design methodologies will be developed, and design of typical elements will be discussed, for the following materials:

• high-strength, ductile materials such as steel and aluminium alloys
• moderately-high-strength, anisotropic, brittle materials such as advanced composites and timber
• materials of low tensile but high compressive strength, such as concrete and masonry
• reinforced concrete where concrete is combined with a ductile tensile material
• brittle materials, such as glass

The critical modes of failure of structures made from these materials tend to differ – for example, global and local instability play a very significant role in thin-walled structures of high-strength materials, while shear-induced delamination is a major concern only in wood and composites.   So design approaches will be correspondingly different.

Overview and General Principles (5L)

• evolution of structural form, with case studies.   Influence of available construction techniques.   Bridge forms and materials economic in certain span ranges.
• requirements of a successful structure (considering collapse, buckling, deflection, cracking, imposed deformation, fatigue, fire, accident, corrosion etc, as well as construction method, cost and sustainability)
• relevant material properties (modulus, anisotropy, strength, toughness, cost, fabrication possibilities, energy content)
• risk, variability, and limit state design (brief introduction)
• Span-to-depth ratio and design.
• ‘load path’ approaches to simplified design, and the ‘lower bound’ theorem as a design tool, with limitations.

Design approaches for different materials

(in most cases, highlighting the important aspects of behaviour, covering the initial design of typical elements such as beams, columns and joints, and studying forms for complete structures).

Ductile Metals (primarily steel) (3L)

Masonry (mention) and Reinforced Concrete (3L)

Timber and Advanced Composites (3L)

Glass (2L)

This syllabus contributes to the following areas of the UK-SPEC standard:

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Last modified: 13/09/2018 14:40

Aims

The aims of the course are to:

• Provide a general understanding of the relationship between the properties of common structural materials, and the principles and approaches underpinning their use in structural design
• Provide a bridge between the fundamental general engineering understanding of structures and materials developed in Part I and the applied specialist modules of Part II
• Provide knowledge and knowhow enabling structural designers to improve our use of energy and material in the design of the built environment while providing safe, useful structures for people to use

Objectives

As specific objectives, by the end of the course students should be able to:

• [1] Use the lower-bound theory of plasticity to perform load-path design of structural arrangements and to appreciate the benefits and limitations of the approach
• [2] Consider the influence of risk, and variability of loading and material properties, in structural design and calculation
• [3] Explain the environmental impacts of structural material and design choices
• [4] Understand and carry out early-stage structural design with various structural materials
• [4.1] Identify the theoretical and practical considerations governing structural design in various materials and explain how these may be accommodated in design
• [4.2] Make reasonable conceptual design decisions regarding appropriate structural form, initial layout and initial member sizing for simple structures in various materials;
• [4.3] Perform preliminary technical design calculations for simple structures in various materials
• [4.4] Determine what design approaches may be appropriate, and what calculations necessary, for more complex structures in various materials

Content

The implications of the general principles of structural mechanics – equilibrium, compatibility, constitutive laws, and stability – are investigated for different materials. This leads to discussion of typical structural forms in the various materials, the reasons for adopting them, and appropriate methods of construction. The significant types of structural behaviour, and therefore the most useful methods of analysis and calculation, are investigated for the different material types. Our basic aim is to establish means of making reasonable preliminary decisions about structural form, layout and initial sizing of structural members made from a range of common construction materials.

Design methodologies will be developed, and design of typical elements will be discussed, for:

• materials of low tensile but high compressive strength, such as masonry and glass;
• composite materials of low tensile strength combined with a ductile tensile material, such as reinforced concrete;
• high-strength, ductile materials such as steel and aluminium alloys;
• moderate-  to high-strength, anisotropic, brittle materials such as engineered timber.

The critical modes of failure of structures made from these materials tend to differ, as do other considerations such as environmental impacts, so design approaches will be correspondingly different.

Weeks 1-2 provide an introduction to a number of important considerations and approaches in structural design across materials, such as: loadpaths and the lowerbound theorem; limit state design and variability; resource efficiency and sustainability

Weeks 3-8 apply these considerations and approaches to design with various structural materials including: masonry; glass; reinforced concrete; steel and timber.

This syllabus contributes to the following areas of the UK-SPEC standard:

Toggle display of UK-SPEC areas.

 
Last modified: 24/05/2022 15:53

Aims

The aims of the course are to:

• Develop an understanding of the dynamics of an aircraft in flight, and an appreciation of how their characteristics may be improved using automatic control systems.

Objectives

As specific objectives, by the end of the course students should be able to:

• Appreciate how the equations of motion for an aircraft follow from Newton's second law, and how they may be simplified to the small-disturbance form;
• Understand how the free modes of motion follow from the equations of motion, and be aware of the approximate derivations of the modes;
• Know the factors determining the static stability of an aircraft, and understand the significance of the position of the centre of gravity;
• Have a knowledge of basic control strategies for autopilots, and their effects on aircraft stability;
• Appreciate that the dynamic characteristics of the aircraft may be improved by feedback control, and understand how this concept applies to stability augmentation systems, and command augmentation systems.

Content

The flight test part of this module has a number limit. If it is oversubscribed, selection will be made on a competitive basis, subject to priority being given to students in Engineering Areas 3 (Aerospace and Aerothermal Engineering) and 8 (Instrumentation and Control). The module can be taken without participating in the flight tests.

Please also note that the first 4A4 lecture will be a briefing session only (lectures start in week 5).  Attendance at the briefing session is essential; if you are forced to miss it, contact the course leader by the end of week 1 at the latest.

Aircraft Stability (8L, Michaelmas term, Dr W.R. Graham)

• Aircraft equations of motion, small disturbance form, stability derivatives.
• Longitudinal motion: phugoid mode, short period oscillation and approximate forms.
• Lateral motion: roll subsidence, dutch roll, spiral mode and approximate forms.
• Static stability of aircraft: longitudinal stability, directional stability, lateral stability.

Automatic Control Systems (6L, Lent term, Dr M. Vera Morales)

• Root locus plots and their use in designing feedback control systems.
• Response to control inputs.
• Autopilots: pitch and roll angle control, effect on aircraft dynamic response and stability.
• Stability augmentation systems: pitch rate SAS & yaw damper as means of improving dynamic stability characteristics, relaxed static stability.
• Command augmentation systems: C-star criterion as basis for longitudinal CAS in fly-by-wire aircraft.

This syllabus contributes to the following areas of the UK-SPEC standard:

Toggle display of UK-SPEC areas.

 
Last modified: 08/06/2023 16:15

Aims

The aims of the course are to:

• Develop an understanding of the dynamics of an aircraft in flight, and an appreciation of how their characteristics may be improved using automatic control systems.

Objectives

As specific objectives, by the end of the course students should be able to:

• Appreciate how the equations of motion for an aircraft follow from Newton's second law, and how they may be simplified to the small-disturbance form;
• Understand how the free modes of motion follow from the equations of motion, and be aware of the approximate derivations of the modes;
• Know the factors determining the static stability of an aircraft, and understand the significance of the position of the centre of gravity;
• Have a knowledge of basic control strategies for autopilots, and their effects on aircraft stability;
• Appreciate that the dynamic characteristics of the aircraft may be improved by feedback control, and understand how this concept applies to stability augmentation systems, and command augmentation systems.

Content

The flight test part of this module has a number limit. If it is oversubscribed, selection will be made on a competitive basis, subject to priority being given to students in Engineering Areas 3 (Aerospace and Aerothermal Engineering) and 8 (Instrumentation and Control). The module can be taken without participating in the flight tests.

Please also note that the first 4A4 lecture will be a briefing session only (lectures start in week 5).  Attendance at the briefing session is essential; if you are forced to miss it, contact the course leader by the end of week 1 at the latest.

Aircraft Stability (8L, Michaelmas term, Dr W.R. Graham)

• Aircraft equations of motion, small disturbance form, stability derivatives.
• Longitudinal motion: phugoid mode, short period oscillation and approximate forms.
• Lateral motion: roll subsidence, dutch roll, spiral mode and approximate forms.
• Static stability of aircraft: longitudinal stability, directional stability, lateral stability.

Automatic Control Systems (6L, Lent term, Dr M. Vera Morales)

• Root locus plots and their use in designing feedback control systems.
• Response to control inputs.
• Autopilots: pitch and roll angle control, effect on aircraft dynamic response and stability.
• Stability augmentation systems: pitch rate SAS & yaw damper as means of improving dynamic stability characteristics, relaxed static stability.
• Command augmentation systems: C-star criterion as basis for longitudinal CAS in fly-by-wire aircraft.

This syllabus contributes to the following areas of the UK-SPEC standard:

Toggle display of UK-SPEC areas.

 
Last modified: 31/05/2024 09:57