3.19 Techniques for Analysing Earthquake Response
127
Prob. 3.43
3.44 A machine component vibrates with a frequency of 60 Hz. If an accelerometer
having negligible damping and having weight and spring constant of 6 and
150 N/mm indicates a total travel of 8 mm, what are the maximum amplitude
and maximum acceleration of the machine component?
3.45 The natural frequency of a vibrometer is 30 rad/s. When it is used to
record the vibration of a machine component, the reading obtained was
2 mm, at operating frequency of 150 rad/s, ζ = 0.02. What is the maximum
displacement?
3.46 Based on response spectra of Fig. 3.34, determine the maximum displacement
and base shear for a SDF system having m = 50 kg, k = 800 N/mm and c =
20 Ns/mm.
3.47 A damped system having m, k and c experiences a base acceleration as
shown in the figure. The initial conditions are all zero. Derive expressions for
maximum relative displacement and maximum absolute acceleration.
Prob. 3.47
3.48 An automobile is moving over a multispan elevated roadway supported at
every 30 metres. Due to long-term creep, the roadway has become a wavy
surface with 150 mm deflection of the middle of each span. The profile can be
127
Prob. 3.43
3.44 A machine component vibrates with a frequency of 60 Hz. If an accelerometer
having negligible damping and having weight and spring constant of 6 and
150 N/mm indicates a total travel of 8 mm, what are the maximum amplitude
and maximum acceleration of the machine component?
3.45 The natural frequency of a vibrometer is 30 rad/s. When it is used to
record the vibration of a machine component, the reading obtained was
2 mm, at operating frequency of 150 rad/s, ζ = 0.02. What is the maximum
displacement?
3.46 Based on response spectra of Fig. 3.34, determine the maximum displacement
and base shear for a SDF system having m = 50 kg, k = 800 N/mm and c =
20 Ns/mm.
3.47 A damped system having m, k and c experiences a base acceleration as
shown in the figure. The initial conditions are all zero. Derive expressions for
maximum relative displacement and maximum absolute acceleration.
Prob. 3.47
3.48 An automobile is moving over a multispan elevated roadway supported at
every 30 metres. Due to long-term creep, the roadway has become a wavy
surface with 150 mm deflection of the middle of each span. The profile can be