Question

(10 points) Define relaxation modulus and draw how it changes with increasing temperature for a glassy polymer (15 points) Define relaxation time, and elaborate a reasoning to predict changes with temperature. 1. 2. (75 points) Derive the response of a Maxwell element in an engineering stress-strain test in which the rate of tensile strain is maintained constant. 3. Assume e 0 for t 0 and reasonable values for the constants: (a) Plot stress as a function of time. (b) Plot strain as a function of time (c) Plot stress as a function of strain for four different values of strain rate. Solution

Answer 1

DATE 6

strain as valu 10 Ca