to keep size down many pictures and the links on this presentation were not included for the...
TRANSCRIPT
• To keep size down many pictures and the links on this presentation were not included for the proceedings. If you wish to receive a CD with the full content please contact me at: [email protected]
Materials and Structures
Anthony Somers
Ashwood College
Materials Engineering
Materials and Structures
• Introduction• Topic Breakdown• Demonstrations and Practicals• Sample Problems• SAC• Textbooks• Careers • Resource CD
Materials and Structures
Design and materials combine to make successful structures
Materials and Structures
Why is it important?
• Tacoma Narrows Bridge
Structural Failures
Structural Failures
Westgate Bridge
• During construction
• Two sides not aligned
Structural Failures
Westgate Bridge
Original design 40000 vehicles 25t max
Present day 250000 vehicles 68t max
Structural Flaws
Investigating how structures fail……...
Structural Flaws
Any concerns?
Structural Flaws
Is this a safe work environment?
Materials
Materials
Price $10,000
Price $1600
Why?
Materials and Structures
The success of any structure depends on:
• The design of the structure
• The materials used in the structure
Materials and Structures
Topic breakdown
• Study Design
• Exams
Materials and Structures
Exam breakdown
• Forces in Structures (Structure) 31%
• Stress/Strain Curve (Materials) 50%
• Composites (Steel/Concrete) 14%
• Terms 5%
Materials and Structures
Main Topics with Presentations
• Forces in Structures
• Stress/Strain Curve
• Composites
Forces in Structures
Forces in Structures
Understanding
• Types of loads
• Forces in structure elements
Forces in Structures
There are five different types of load–Tension (stretching)–Compression (squashing)–Shear (sliding)–Bending–Torque (rotating)
Load Demonstration
Forces in Structures
Force type analysis in structures
Construct structures
Stress/Strain Curve
Stress/Strain Curve
Many terms:
• Stress
• Strain
• Young’s Modulus
• Strength
• Stiffness
• Elastic
• Plastic
• Brittle
• Tough
• Yield Point
Stress/Strain Curve
Stress and Strain
• Killer Pythons and Snakes
Which is stronger?
Stress/Strain Curve
Stress and Strain
• Used to compare materials of different dimensions
• Stress = Force/Area
• Strain = Change in Length/Original Length
Stress/Strain Curve
Stress
Strain
Stress/Strain Curve
Stress
Strain
Stress
Strain
Constant speed Measure stress and strain
Increasing weight Measure strain
Types of Tensile Testing
Stress/Strain Curve
Tensile Test Video
Stress/Strain Curve
Material Properties
• Plastic/Elastic
• Brittle/Tough
Demonstrate with silly putty
Available from CSIROSEC
Composite Materials
• Second material inside first to increase toughness
• Carbon fibre composite, reinforced concrete, fiberglass
• The reinforcing spreads the energy of the crack
Toughness Demonstration
Sample Problems
Sample Problems
For stability: Forces: R = F1 + F2
Torque about R: F1x1=F2x2
x1 x2
F1F2
R
Forces in Structures
Sample Problems
Fw Beam weight
Strut
Load Weight
x
60°
30°Fs
Forces in Structures
Sample ProblemsComposites
Assessment
SAC – Great for data analysis
• 2007 SAC
Materials and Structures
Textbook Analysis
Textbook Analysis
Jacaranda
• brief on force in structures
• covers stress/strain curve and composites well
Textbook Analysis
Nelson
• force in structures well covered
• stress/strain curve OK confusing order
• composites very brief
Textbook Analysis
Heinemann
• force in structures very brief
• stress/strain curve very well covered
• composites very well covered
Careers
What do materials engineers do?
• Select appropriate materials
• Develop new materials
Careers
What do materials engineers do?
• Failure Analysis
• Test materials
Careers
What do materials engineers do?
• Predict material lifetimes
Materials and Structures
Careers – Monash University
• Materials Engineering
More information:
• Materials Engineering Brochure
• www.monash.edu.au/materials
Materials and Structures
Anthony Somers
• If you want data for data analysis SAC
• Post on Edulists (edulists.com.au)
• Experiment ideas to be passed on
Structural Failures
Tacoma Narrows Bridge (wikipedia)
– Sides of bridge solid, catch wind
– Deck of bridge too light