L3: Mechanical Behaviour 2 Flashcards Preview

Ma ME523: Polymer And Polymer Composites > L3: Mechanical Behaviour 2 > Flashcards

Flashcards in L3: Mechanical Behaviour 2 Deck (7)
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1

What is the advantage and disadvantage of the KV and Maxwell models?

KV: acceptable approximation for creep/recovery behaviour. Does not account for stress relaxation
Maxwell: Can account for stress relaxation. Poor description of creep and recovery

2

What is the arrangement of the Standard Linear Model?

1 large spring in parallel with a spring and dashpot which are in series

3

What is the initial extension and relaxation behaviour controlled by in the SLM?

Initial: the dashpot
Relaxation: the interplay of both spring and dashpot elements

4

What is the asymptotic value for strain in the KV model?

stress/E

5

What constants must be chosen to show the KV and Maxwell models are special cases of the SLM?

Maxwell: E2 (big spring) = 0
KV: E1 (small spring) = infinite (divide through by E1)

6

Which factors form a 3D relationship for viscoelastic polymers?

stress-strain-time

7

How is D(t) (creep compliance) determined?

Usually will be told to use Maxwell or KV model - D(t) = strain(t)/stress
See slides for equation for each