A NEW DAMAGE DETECTION INDEX BASED ON BEAM MODE SHAPE SLOPE

A new damage index, called mode shape slope difference (MSSD), is proposed to predict the damage locations in beam structures. Unlike most vibration based damage detection methods, which use the undamaged state of the beam as reference, the MSSD index utilizes only the damaged state. It is derived by using two different approximation formulas for the first derivative of the damaged beam mode shape. To assess the effectiveness and the accuracy of the MSSD index method two test examples of finite element models are considered. The results obtained demonstrate that the proposed damage index correctly predicts the damage locations in beam structures with single or multiple damages.