Modal passport of dynamically loaded structures: application to composite blades

Abstract

Close relation of modal properties to mechanical properties of structures presents interest for applied research and solutions of Structural Health Monitoring (SHM) tasks. The paper considers application of analytical and modal analysis techniques for structural research and monitoring of composite blades as well as required measurement tools. The Roving Hummer Technique (RHT) and Operational Modal Analysis OMA) were admitted as optimal methods for modal properties estimation, but 3-axial accelerometers and vibration deformation sensors – as most acceptable measurement tools. There is discussion of methodology and technical aspects required for modal properties estimation of static and rotating blades. Samples of composite blades preparation for measurements and equipment applied for testing are considered. Authors discuss the modal passport concept as the platform for applied studies of modal properties and for diagnostic purposes including Structural Health Monitoring (SHM) of operating structures. Typical modal passport structure is described as the set of modal parameters that are common for same type of blades and generalized dependences of modal parameters from operational factors. The paper discusses the principles of modal passport application for a particular blade based on its individual modal properties. There are conclusions about application of typical modal passport in industry.