Use of Tracking-Continuous Scanning LDV (T-CSLDV) methods for vibration study of bladed disk assembly under operating conditions

The aim of this paper is to present a series of measurement methods and excitation methods for the study of the vibratory state of bladed discs under rotating conditions. Scanning Laser Doppler Vibrometer (SLDV) is, probably, one of the best non-contact transducer to measure vibrations of very sensitive structures such as bladed discs. The SLDV has been used to develop measurement methods where the laser spot is not stepping over a grid of predefined points but it moves continuously over the vibrating surface achieving a full-field measurement. A number of methods, Continuous Scanning LDV (CSLDV) methods, were developed to be performed either under stationary conditions or under rotating conditions. All those were collected in a software platform called CAISER MYMESIS which also runs Virtual Test Simulators (VTS) of the actual measurement methods. Point tracking, line tracking and area tracking are performing Tracking-CSLDV measurements. All these techniques can be used with a series of excitation methods which are: Engine Order (EO) method using a fix DC magnet, AC magnet (fixed or rotating) method and impact excitation method. Hence, depending on the dynamic nature of the bladed disc structure, for example high or low modal density, it is possible to combine excitation and measurement methods to output the desired information.