Material Selection

Question 1

What are the 4 steps in material selection?

Answer 1

1. Translation
2. Screening
3. Ranking
4. Documentation

Question 2

Define translation?

Answer 2

Define component functions, constraints, objectives, free variables

Question 3

Define screening?

Answer 3

Eliminate materials that don’t meet the constraints

Question 4

Define Ranking?

Answer 4

Order materials by performance to meet objectives - select handful of best materials

Question 5

Define documentation

Answer 5

Explore aspects of the shortlisted material candidates in depth, to produce a final selection

Question 6

What are some typical constraints?

Answer 6

• Be strong enough
• Conduct electricity
• Tolerate 250 degrees in use

Question 7

What are some typical objectives - what should be maximised and minimised?

Answer 7

• Mass
• Volume
• Environmental impact indicator
• Cost

Question 8

What do two dimensional material property charts show?

Answer 8

Material families which occupy discrete fields

Question 9

How does speed travel through a solid and how is it defined?

Answer 9

v = (E/ρ)^1/2

Question 10

What are material indices?

Answer 10

A grouping of material properties which, if maximized or minimized, maximizes some aspect of the performance of an engineering component - forms an equation

Question 11

What are some general matrices for ties, beams and panels?

Answer 11

Ties - E/ρ, i.e., slope = 1
Beams - E^1/2/ρ, i.e., slope = 2
Panels - E^1/3/ρ, i.e., slope = 3

Question 12

How is documentation done?

Answer 12

• Done using various resources
• Explore case studies
• Explore design guidelines

Question 13

What is a shape factor?

Answer 13

• The shape factor 𝜙 is a dimensionless scalar
• Independent of dimensions but affected by geometry

Question 14

What is the shape factor for elastic bending stiffness?

Answer 14

Bending stiffness S ∝ EI

Question 15

What is the bending strength factor?

Answer 15

6Z/A^(3/2)

Question 16

What is considered in product life cycles?

Answer 16

• Emissions from product fabrication and manufacturing
• Emissions from product use
• Emissions from product disposal
• Emissions from material production

Question 17

What does LCA stand for?

Answer 17

Life cycle assessment

Question 18

How can environmental impacts arise?

Answer 18

• Resource depletion
• Energy consumption
• Emissions of CO2, NOx, SOx gases
• Toxic residues

Question 19

True of false - high relative energy products have a worse impact on the environment during the manufacturing process than in use?

Answer 19

False

Question 20

What does second moment of area stand for?

Answer 20

Describes the distribution of area around the reference axis