Question

9. For the frame shown below, the stiffness of fixed column is 12El/L3 and for the pinned is 3EI/L, I for W 8 x 24 82.8 in4, I for W 10x 33 170 in, E-29,000 ksi. Find: (2 Points each subsection) (i) Total Stiffness. (i) Natural Frequency in rad/sec. and Hz, and Period. i) Assuming the damping is negligible, find displacement, velocity and acceleration at t 5 sec. using initial conditions yo 0.75 inch and vo 20 inch/sec. How much weight should be added to increase the period by 25%. Assume the damping ratio (-10%. Calculate Critical Damping Coefficient Ccr , Damping Coefficient c, Damped Frequency øp, displacement of the structure at time t 5 sec. for initial conditions yo -0.75 inch and vo 20 inch/sec. (iv) Rigid W- 30 kips 15 ft W8X24 W10x33 w8x24 5 ft 20 ft 20 ft

Answer 1