Teacher Development Program Bringing schools and Engineering together. Year 12 Civil Structures Module

Transcription

1 Teacher Development Program Bringing schools and Engineering together Year 12 Civil Structures Module

2 Teacher Development Program Bringing schools and engineering together INTRODUCTION Civil structures The teacher development program provides current, industry related engineering context to the HSC engineering studies course. This module is part of a series of 8 modules providing relevant material to the course learning outcomes. The presentations provide a forum for teaches to network and interact with Engineers Australia. WE AIM TO BE A FACILITATOR IN SUPPORTING YOU.

3 Teacher Development Program Bringing schools and engineering together Drop box We have created an ENGINEERING STUDIES RESOURCE CENTRE on Dropbox. This can be used by Teachers and Engineers Australia to share and communicate useful resources. This Module

4 This Module

5 The Syllabus-HSC Modules Student Learnings

6 Syllabus- Objectives and Outcomes P1.1. identifies the scope of engineering and recognises current innovations Engineering Scope P1.1: Engineers and engineering are indispensable contributors to Australian prosperity and lifestyles. Engineering services are embodied in almost every good or service consumed or used by Australians, now and in the future. Engineers are the enablers of productivity growth through their role in converting brilliant ideas into new products, new processes and new services. Engineers also ensure that society gets the most out of existing facilities through optimising their operations and maintenance. es/statistical_overview_2015.pdf

7 Syllabus- Objectives and Outcomes H1.1. describes the scope of engineering and critically analyses current innovations Engineering Scope H1.1: Critical Analysis of current innovation. Innovation is defined as: The process of translating an idea or invention into a good or service that creates value or for which customers will pay. To be called an innovation, an idea must be replicable at an economical cost and must satisfy a specific need. Engineering Solutions must be analysed to be: Repeatable- (when tested over and over in same facility) Reproducible- (when tested in different facilities)

8 Engineering Materials H1.2 - differentiates between the properties and structures of materials and justifies the selection of materials in engineering applications. H2.1 determines suitable properties, uses and applications of materials, components and processes in engineering. Material properties Classification:- 4 main groups: 1. Metals- Iron, Steel, Copper etc. 2. Polymers- Bakelite, PVC 3. Ceramics- Glass, Abrasives 4. Composites- Concrete, Fibreglass, FRP

9 Ages of Materials Early Humans- Stone Age ~9000 BCE- Copper age ~3000 BCE- Bronze age ~1200 BCE- Iron age

10 Steel Iron Steel Hot-Rolled Hot-Rolled Cold Rolled Cold-Rolled Protection Galvanised

11 Polymers Products A long chain molecule Medical Transport Clothing Construction

12 Ceramics

13 Glass Ceramics

14 Composites- Use

15 Composites- Concrete Concrete the material: Strong in compression / weak in tension Brittle material will crack- controlled by joints etc. Reinforcement in tension zones mainly Cover to reinforcement important for durability Lifecycle- potential for 100 years or more Commonly 10 to 40 years project dependent Can form a composite with any other compatible material- steel, plastic, fibres, corn husk, straw, hemp etc. depending on properties sought.

16 Important Material Properties Compression Tension Bending Torsion Shear

17 H4.1- investigates the extent of technological change in engineering. Changes in technology for analysis and deign (model of the physical world)

18 Advances in technology and analysis systems have allowed better understanding of materials and allowed more efficient structures.

19 How do buildings resist lateral loads? 19 C a n t i l e v e r s

20 Outriggers allow activation of more of the structure and increases the efficiency of the structure.

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23 Teacher Development Program Bringing schools and engineering together H4.3 applies understanding of social, environmental and cultural implications of technological change in engineering to the analysis of specific engineering problems. Engineering Innovation in Civil Structures and their Effect on People s Lives Large buildings have allowed for apartments and businesses to work in better environments. Bridges allow people to cross water ways easily and quickly. Impacts of bridges include: More direct travel across waterways, gorges Quicker travel times Less fuel used in traveling, cheaper Job opportunities in design and construction Pylons may disturb waterways Negative impact on boating

24 Teacher Development Program Bringing schools and engineering together Construction and Processing Materials used in Civil Structures Over Time Timber Stone Strong in compression but heavy Cast Iron Steel Corrodes, strong in tension and compression Concrete artificial rock relatively strong in compression Environmental implications from the use of materials in civil structures Timer Deforestation Stone Needs to be quarried, cut, transported Steel Pollutants from smelting Concrete

25 Teacher Development Program Bringing schools and engineering together Trusses

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31 Teacher Development Program Bringing schools and engineering together H3.3 develops and uses specialist techniques in the application of graphics as a communications tool Truss Analysis Pin jointed frames. No transfer of bending at the joints. Axial forces only (1) Method of joints This involves working around the truss, solving one joint at a time to find the axial forces in each of the members. This method requires the understanding of the sum of vertical and horizontal forces = zero. It usually requires the application of trigonometry and simultaneous equations. (The first two equations of equilibrium) The concept of axial forces in a member (No bending)

32 Teacher Development Program Bringing schools and engineering together (2) Method of sections This involves cutting the truss at a discrete location in order to fint the forces in the members at the particular cut. This technique required the understanding of the theory of moments about a point = zero. (The third equation of equilibrium) The concept of axial forces in a member (No bending)

33 Teacher Development Program Bringing schools and engineering together Simple beam Analysis Concepts of flexural (bending) actions.

34 Teacher Development Program Bringing schools and engineering together Shear force and bending moment diagrams Here is a beam (top), with the corresponding shear force diagram (middle), and bending moment diagram (bottom) subject to a point load

35 Teacher Development Program Bringing schools and engineering together Shear force and bending moment for a beam subject to a uniformly distributed load.

36 Teacher Development Program Bringing schools and engineering together Concept of shear force and bending moment Sum of vertical forces = zero Sum of moments = zero Satisfy equations of equilibrium

37 Teacher Development Program Bringing schools and engineering together Bending stress induced by point loads only

38 Teacher Development Program Bringing schools and engineering together Stress and Strain Shear Stress Shear stress occurs when you apply shear force. Eg. If a bolt is supporting a load perpendicular to the bolt of 10kN, and it has a diameter of 10mm, what is the shear stress? Shear stress = 127MPa

39 Teacher Development Program Bringing schools and engineering together Yield stress, Proof stress, Toughness, Young s modulus, Hooke s law, Engineering applications Yield stress occurs when there is an increase in strain without an increase in stress. Proof stress is the amount of stress necessary to bring a permanent strain in the material. Toughness is a measure of the ability of a material to absorb energy. Hooke s law is, it calculates Young s modulus of elasticity. Factor of Safety A factor of safety is how many times stronger the material or structure is than it needs to be.

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41 Teacher Development Program Bringing schools and engineering together H3.1 demonstrates proficiency in the use of mathematical, scientific and graphical methods to analyse and solve problems of engineering practice. The study of a Higher level of Mathematics is very important for carrying out engineering calculations. Civil (structural) engineering is about modelling the physical world to understand it s behaviour by the use of applied mathematics. Calculus, for example, is just one key part of mathematics that is used for determining the bending moment and shear forces ( and therefore stresses) in structures. The accurate calculation is very important in the analysis (understanding forces) and design (sizing elements to withstand the forces). Manual (hand) calculations is still very much used and taught in 3 rd year engineering degrees. It allows simple checking of output of computer analysis for sensibility and errors.

42 Teacher Development Program Bringing schools and engineering together For the simple beam with a distributed load (w) shown, the shear force at C is taken as:

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45 Teacher Development Program Bringing schools and engineering together Calculus and the use of Differentiation and Integration

46 Error between model and physical world.

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52 Summary Engineers Australia is your link with the Engineering Profession / Industry These Presentations and forums can provide important networking opportunities with other teaching professionals Engineers Australia can assist in providing exciting ways of presenting concepts with real world examples and applications. We encourage a link of support with exam assessors We emphasise that pathways to engineering exist for all students- Professional, Technical, Trade, VET

53 Pathways to Engineering Primary School High School University Professional Life Discover engineering HSC Bachelor Degree MIEAust Maths Careers Night Engineers Australia CPEng Early science Teacher Networking Higher degrees VET Trade course Masters degree Professional engineer TAFE Professional Engineer Futher study Technologist Research degree Acadmeic Associate

54 Engineers Australia is the trusted voice of the profession. We are the global home for engineering professionals renowned as leaders in shaping a sustainable world. engineersaustralia.org.au