Material Selection Flashcards
What are the 4 steps in material selection?
- Translation
- Screening
- Ranking
- Documentation
Define translation?
Define component functions, constraints, objectives, free variables
Define screening?
Eliminate materials that don’t meet the constraints
Define Ranking?
Order materials by performance to meet objectives - select handful of best materials
Define documentation
Explore aspects of the shortlisted material candidates in depth, to produce a final selection
What are some typical constraints?
- Be strong enough
- Conduct electricity
- Tolerate 250 degrees in use
What are some typical objectives - what should be maximised and minimised?
- Mass
- Volume
- Environmental impact indicator
- Cost
What do two dimensional material property charts show?
Material families which occupy discrete fields
How does speed travel through a solid and how is it defined?
v = (E/ρ)^1/2
What are material indices?
A grouping of material properties which, if maximized or minimized, maximizes some aspect of the performance of an engineering component - forms an equation
What are some general matrices for ties, beams and panels?
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
How is documentation done?
- Done using various resources
- Explore case studies
- Explore design guidelines
What is a shape factor?
- The shape factor 𝜙 is a dimensionless scalar
- Independent of dimensions but affected by geometry
What is the shape factor for elastic bending stiffness?
Bending stiffness S ∝ EI
What is the bending strength factor?
6Z/A^(3/2)
