Comparative study of finite element analysis and geometrically exact beam analysis of a composite helicopter blade

2018
Ataç, Meryem Nisa
In this master thesis, comparative study of the finite element analysis and geometrically exact beam analysis of a composite helicopter blade is performed. The objective of this study is to investigate the applicability of the geometrically exact beam analysis of the composite helicopter blade in predicting the structural response of the composite blade. To evaluate the structural response determined by the geometrically exact beam analysis of the composite blade, detailed finite element model of the blade is prepared and the structural response of two methods are compared for different static and transient load cases and dynamic analysis. Geometrically exact beam analysis utilizes variational asymptotic beam section analysis for the calculation of sectional stiffness and mass matrices, and general deformation of the blade for the static and transient load cases can be determined with high accuracy. Three dimensional stresses in the selected blade sections can also be determined via the stress recovery feature of the variational asymptotic beam section method. It is shown that the neutral axis, shear center, still air natural frequency, static and transient displacement and static stress analysis results determined by the geometrically exact beam analysis match perfectly with the finite element analysis results for the rectangular section and airfoil section blade models studied. It is considered that especially for the structural design of the airfoil sections of the blade, which requires many re-analyses due to frequent design changes in the detailed design stage, geometrically exact beam analysis can replace finite element method which requires longer modelling times to reflect the design changes.
Citation Formats
M. N. Ataç, “Comparative study of finite element analysis and geometrically exact beam analysis of a composite helicopter blade,” M.S. - Master of Science, Middle East Technical University, 2018.