An applied strain of 0.5 produces an immediate stress of 2 MPa in a piece of rubber, but after 10 days, the stress is only 1 MPa. For the following, assume the material obeys a single-exponential relaxation process.
a) What is the relaxation time?
b) What is the stress after 100 days?
Initial stress, 0 = 2 MPa
At t = 10 days, stress, (10) = 1 MPa ...
For single exponential process, relaxation time and stress at a given time are estimated.