Question

Choose the best option:

- Viscoelastic stress relaxation

- Viscoelastic creep

Although the viscoelastic response of a polymer can be very complex (time-dependent stress cycling for instance), two special loading scenarios are fairly simple to describe mathematically.

1. _______ refers to scenarios for which the stress applied to a polymer must decay over time in order to maintain a constant strain. Otherwise, over time, the polymer chains will slip and slide past one another in response to a constant applied load and the strain will increase (in magnitude).

2. ________ refers to scenarios for which a polymer will permanently flow over time in response a constant applied stress.

Answer 1

1. Viscoelastic stress relaxation refers to scenarios for which the stress applied to a polymer must decay over time in order to maintain a constant strain. Otherwise, over time, the polymer chains will slip and slide past one another in response to a constant applied load and the strain will increase (in magnitude).

2. Viscoelastic creep refers to scenarios for which a polymer will permanently flow over time in response a constant applied stress.

1) When Viscoelastic stress relaxation occurs - step constant strain causes decreasing stress

2) When Viscoelastic creep occurs - step constant stress causes increasing strain