(a) Model Stress Input (b) ww ww 9. E 0 2 0 3 4 Strain Response [G/E 0 3 4 2 Figure 2. Creep models having time-dependent behavior and their responses to a stress- time step. Model (a) exhibits steady-state creep with elastic strain added, and model (b) transient creep with elastic strain. (referring to Lecture note 7 or page 8 of reading materials 4) 3. At 500C, a material has an elastic modulus of E= 70 GPa and a tensile viscosity of = 1200 GPa-s. Assuming that the elastic, steady-state creep model of Figure 2(a) applies, determine the response to a stress of 50 MPa maintained for 5 minutes and then removed. Plot both the strain versus time and stress versus strain for a total time of interval of 10 minutes.