Crack detection using nonlinear output frequency response functions

The new concept of nonlinear output frequency response functions (NOFRFs) is introduced in this paper to detect cracks in beams using frequency domain information. The results show that the NOFRFs are a sensitive indicator of the presence of cracks providing the excitation is of an appropriate intensity. They also constitute an indicative and promising basis, which must further be explored, so that the method can be used for the detection of cracks in beams with applications in structural fault diagnosis.