代做Using multiple absorbers代做Matlab语言

Using multiple absorbers

In the vibration absorber short lab you have looked at the effect of adding a tuned mass damper (TMD) to the structure to reduce the amplitude of vibration at resonance. While this was accomplished, the TMD also introduced two additional resonant peaks, at frequencies each side of the original peak. In an earthquake, excitation of the structure occurs over a range of frequencies, and these two peaks (even though lower) may still produce unacceptably large vibration. Additionally, in a real structure, it may be more practical to have multiple small absorbers, rather than a few large ones. In this experiment, you are to investigate the use of multiple absorbers, tuned such that they spread the peaks and reduce vibration over a range of frequencies.

Using an Octave/Matlab model of the structure, carry out a similar analysis to that done in the vibration absorber short lab, but using multiple absorbers. Here are a few suggested questions to investigate:

Compare, for example, the effects of using 1, 10, 100 and 1000 absorbers tuned to slightly different frequencies (with the same total mass in each case). Which gives the widest spread?

What is the minimum total mass of absorbers required to reduce the maximum (harmonic) response of the structure to, say, 10% of its value with no absorbers?

How does this change if you analyse the impulse response? Is there are trade-off between the optimum tuning to deal with harmonic and impulse responses?

Can you think of a way to test these predictions on the structure?