Question

Use a plotting routine to examine the base motion problem (see Figure 2.13) by plotting the particular solution (for an undamped system) for the three cases k = 1500 N/m, k = 2500 N/m, and k = 700 N/m. Also note the values of the three frequency ratios and the corresponding amplitude of vibration of each case compared to the input. Use the following values: 6) = 4.4 rad/s, m = 100 kg, and Y = 0.05 m.

Figure 2.13 (a) Base-excitation problem models the motion of an object of mass m as being excited by a prescribed harmonic displacement acting through the spring and damper (b) A free-body diagram of the base motion problem in (a). 

Answer 1

For case(i)

Amplitude is 0.028 m

For case(ii)

Amplitude is 0.022 m

For case(iii)

Amplitude is 0.041 m