Study on output error of substructural system induced by local damages of structures

This paper presents the characteristics of the output error computed as a difference between observation output and simulated output at internal node of the substructure which extracted from whole structure virtually. The output error has been used as a damage index of substructure in our proposed local damage detection method but has not been shown its causal relationship to the damages. Analytical and numerical studies using the simple 2-dimentional frame model are conducted in this paper to enhance understanding of the relation of output error and structural damages. The output error is formulated by transfer functions inside the substructure. And the formulation shows that the increase of output error induced by structural damages mainly occurs in the rotational component of the substructure response.