A new crack size prediction method using damaged beam mode shape

There are many mode shape damage localization methods but a few of them assess damage severity. In this paper a crack size prediction method using damaged beam mode shape is presented. The beam damaged sections are modelled by massless rotational springs, whose constants are calculated by the first and the second derivate of the mode shape using numerical differentiation. The method utilizes the relationship between the rotational spring constant and the size of an open single-sided crack with uniform depth in a rectangular cross section beam. The predicted crack depths are compared with the actual data from finite element models. The results obtained demonstrate that the proposed method correctly predicts the crack size in beam structures with single or multiple damages.