The key conclusions of this research are:

1. The EFXLMS algorithm demonstrated superior performance than the FXLMS algorithm during fast adaptive processes, in particular for non-stationary inputs.

2. Good attenuation of the peak. and root-mean-square (rms) values of the structural responses using the hybrid control system were observed for most of the real accelerograms. It was also observed that the hybrid control system always improved the performance of the passive control system.

3. Peak. structural responses during sensor failures were observed to increase, in particular for the failure of the first error sensor. However, the peak. responses during these failures never reached the peak. values obtained by the system with passive control. This demonstrated the ability of the control system to contain the structural responses in light of the error sensor failures.

4. Peak. structural responses during control actuator failures were also observed to increase, in particular for the failure of the fIrst control actuator ADVAI. However, the peak. responses during these failures again never reached the peak. values obtained by the system using passive control. This demonstrated the ability of the control system to contain the structural responses in light of the control actuator failures.

5. The use of the adaptive control showed greater attenuation of the structural responses than that observed using the non-adaptive system. This demonstrated that the adaptive control system corrected for uncertainties and errors in the modeling process.