Experimental study on a system identification method for damage assessment

초록

The current study focuses on examining a damage assessment al-gorithm based on a system identification (SI) method with labora-tory experiments. The SI method identifies structural parameters in a finite element model by minimizing the least squared error be-tween measured and analytically computed modal responses. A regularization scheme is applied to alleviate the ill-posedness of an inverse problem by adding a regularization function to the primary error function. A statistical method to assess damage in each struc-tural member is proposed by using the hypothesis test. Modal data from impact vibration were measured through laboratory experi-ments on the model structure. The baseline structural model and baseline properties were determined from experimental results without any damage on the structure. Damage was imposed by saw-cutting the cross section with various depths and identified as the reduction in the structural stiffness of the elements around the crack. Through the experimental works, the applicability of the SI-based damage assessment algorithm has been investigated.