A machine with a mass of 250 kg is placed on isolator and the corresponding free vibration records is as shown in Figure. Determine the type of damping, its stiffness and damping constant. Consider the first 2 cycles. x(t) 0.01 0.008 0.006 0.004 0.002 0 -0.002 -0.004 -0.006 -0.008 -0.01 0 0.5 1 1.5 2 2.5 3 3 t 3.5

The subject is Vibration Engineering

3. Determine the kind of damping and the value of q for the arrow refers to number #1 in the figure below 1 0.8 0.6 8 0.4 0.2 -0.2 2 4 6 10 time(s) A. Overdamping, q equal to zero B. Underdamping, q equal to zero C. Critical damping, q equal to zero D. Overdamping, q more than zero E. Underdamping, q more than zero F. Critical damping, q more than zero G. Overdamping, q less than zero H. Underdamping, q less than zero I Critical damping, q less than zero A B D E G

The 8kg body is moved to the right of the equilibrium position and released from rest at time t = 0. The viscous damping coefficient is 23NS/m and the spring stiffness, K is 38N/m. Determine the damping factor (ratio) of the system. Note: Give your answer to 3 decimal places. Other Parameters: Logarithmic Decrement (8): Answer: 2ng 2T C 8 = In = In1 = 5 wnTd = 5wn X2 Xn+1 1-5 wa 2m k Damping Ratio (5): 5= 2vkm 2mn V(21)2+8 Frequency of damped vibration (wa): wa = 1-Wn Undamped Forced Vibration: Frequency Ratio (): r- Xp-x sin w t Next page Hous page Type here to search