Dynamic analysis of modified composite helicopter blade

• Main Authors: Garinis Dimitrios, Dinulović Mirko, Rašuo Boško
• Format: Article
• Language: English
• Published: University of Belgrade - Faculty of Mechanical Engineering, Belgrade 2012-01-01
• Series: FME Transactions
• Subjects: normal mode; natural frequencies; helicopter composite blade; hexagonal honeycomb core; carbon fiber
• Online Access: https://scindeks-clanci.ceon.rs/data/pdf/1451-2092/2012/1451-20921202063G.pdf
• ISSN: 1451-2092; 2406-128X

In the present study, modal analysis has been performed on modified Gazelle helicopter blade. The construction of the blade is fully composite with the honeycomb core. The approach to determining structure mode shapes and natural frequencies is presented. Modified blade consists of core material, 3D unidirectional composite spar and thin carbon composite facesheets as blade skin. To determine the stiffness of the honeycomb core, the equivalent mass approach was used. Several methods of eigenvalue extraction have been investigated in order to find optimal method which can be used in dynamic analysis of composite structures containing honeycomb cores. Among all extraction methods investigated, it was found that combined Lanczos method is most effective in terms of accuracy and CPU time for eigenvalue extraction in composite structures with honeycomb core having large number of degrees of freedom. Strain energies for first four mode shapes of modified helicopter blade have been calculated using numerical approach and results are presented.