In this paper, a combined approach to damage diagnosis of systems is proposed. The intention is to identify thenatural frequencies and the presence of damage. In a first step, the basic concept of the Hilbert HuangTransform is presented where the empirical mode decomposition is applied on the signal using a sifting processto obtain intrinsic mode functions exhibiting monocomponent behavior. In the next step, the Hilbert Transform isused to identify the frequencies from the well behaved intrinsic mode functions. Finally, a time domain approachknown as beating phenomenon is used to calculate the shift in frequencies and also the presence of damage.Simulations are done on linear and nonlinear structures. Results demonstrate that the proposed methods providea new and useful tool for damage detection and evaluation of structures especially when the frequency shift isminima
In this paper, a combined approach to damage diagnosis of systems is proposed. The intention is to identify thenatural frequencies and the presence of damage. In a first step, the basic concept of the Hilbert HuangTransform is presented where the empirical mode decomposition is applied on the signal using a sifting processto obtain intrinsic mode functions exhibiting monocomponent behavior. In the next step, the Hilbert Transform isused to identify the frequencies from the well behaved intrinsic mode functions. Finally, a time domain approachknown as beating phenomenon is used to calculate the shift in frequencies and also the presence of damage.Simulations are done on linear and nonlinear structures. Results demonstrate that the proposed methods providea new and useful tool for damage detection and evaluation of structures especially when the frequency shift isminima