궤환 가진기를 이용한 모델 개선법

Model updating using the feedback exciter

The updating of the FE model to match it with the experimental results needs the modal information. There are two causes where this methodology is ill-equip to deal with; under-determined and ill-conditioning problem. In this research, the feedback exciter which uses the summation of the white noise and the signals from the measurement sensors multiplied with feedback gains is proposed. The new energy path generated by the feedback exciter changes the modal characteristics of the system and this additional modal information can solve the under-determined problem in the model updating. Through the proper selection of the exciter and sensor locations and the feedback gain, the eigenvalue sensitivity of the updating parameters which cause the ill-conditioning of the sensitivity matrix can be modified. This methodology does not require any additional equipments, makes the acquirement of the additional modal information easy and is robust to the measurement noise.