Online vibration-based crack detection during fatigue testing
Faculty of Applied Engineering Sciences
Engineering sciences. Technology
KEY ENGINEERING MATERIALS
5th International Conference on Damage Assessment of Structures, July 01-03, 2003, Southampton, England
, p. 571-578
When performing fatigue tests, it is essential to monitor the degradation of the structure with an increasing number of fatigue cycles. In this article, a vibration-based damage detection method will be proposed. Such a method has the davantage that it operates online with the fatigue test. Especially for structures with very high fatigue strength, it is important that the test does not have to be interrupted. The damage detection method that will be used is based on a residual generated from a stochastic subspace identification method. The basic idea is that a model for the undamaged structure is identified and that, afterwards, vibration measurements from a possibly damaged structure are confronted with this model. A statistical local approach hypothesis testing is used to assess the deviation of the new data from the nominal model. After introducing the damage detection method, its performance will be illustrated on data from a fatigue experiment. The method will be compared to other linear and non-linear vibration-based damage detection methods.