Question

uestion 2 (25% total a) For a lightly-damped SDOF system, let x, and 1,- be the free vibration displacement amplitudes at the initial (reference) moment and m cycles later, respectively. (15%) In the class we concluded that the damping ratio can be estimated using logarithmic decrement as (LI) 27m Does this method still work if instead of displacement amplitudes, we use velocity amplitudes? That is, can be estimated based on 1+m where v, and Vi+ are the free vibration velocity amplitudes at the initial (reference) moment and m cycles later, respectively? Hint: You may need to differentiate the free vibration displacement response derivied in class to get the free vibration velocity response

Answer 1

-私, t Sin i _ SinWo Ls 0 lt ia vali ^.