A pin jointed frame shown below support a gravity load of 1200 lb at C. An impulse cause the frame to vibrate freely in horizontal direction with a velocity of 0.2 ft/s. Derive an expression for calculating lateral and vertical stiffness of system.

Also Calculate:

1. Amplitude of Equivalent Static force.

2. Time required to complete 3 cycles during free vibration

Diameter of both members is 9/8 in Take ζ = 2% and E= 29,000 ksi

60 30 B A 10 ft