Feature extraction is essential in vibration-based Structural Health Monitoring (SHM). In this paper a special focus is on how features are extracted and conditioned. The first case is a numerical simulation study of a small test structure. The second case is an experimental case where two test subjects of a scaled wooden blade structure are investigated. In the experimental case the measurements are performed over a month in an environment with changing temperature and relative humidity. Two different damage types are made, with increasing severity of the damage. All methods dealing with vibration based SHM are using the changes in the dynamic behavior as an indicator for damage. In the test cases the modal parameters of the structure are used as features and are extracted using operational modal analysis (OMA) in a framework of modal tracking. This paper is part 1 of a series of 4 papers that present experimental SHM investigations with focus on value of detection and value of localization using statistical and physical methods for modal based SHM.
doi: 10.12783/SHM2015/184