Choose a material within design constraints
The idea
List the required performance and the maximum permitted mass before comparing costs.
Step by step
- List the required performance and the maximum permitted mass before comparing costs.
- Remove options that fail either constraint, even if they are cheap.
- Compare the remaining options using the stated preference; a different goal can produce a different choice.
Example
Material A: tested load 14 N; mass 7 g; cost 5 tokens. Material B: tested load 16 N; mass 10 g; cost 4 tokens. Material C: tested load 10 N; mass 5 g; cost 3 tokens.
A model needs a material tested for at least 12 N while weighing no more than 8 g. Which listed material has the lowest cost among those meeting both limits?
Answer
Material A
First remove materials failing either limit. Material A has the lowest stated cost among the remaining options.
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Make a small invented material table with load, mass and cost. Explain why the cheapest material is not always a usable choice.
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