With helicopter design it is essential to ensure that the vibration of the aircraft airframe and major components are not excited by the main rotor frequency which is less able to be modified during the development of the aircraft.
Using the NASTRAN Finite Element technologies, it was possible to calculate the basic airframe natural frequencies and assist the design team to make necessary modifications to the airframe to move those natural frequencies away from the main rotor frequency
As the aircraft was developed the analysis was re-run many times as the detail of the aircraft matured. As a result the design engineers were able to optimize the location and weight characteristics of essential aircraft equipment and weapon systems to ensure that the design specifications could be met.
I developed the airframe finite element models and generated the necessary data input decks for processing. I was also responsible for the integrity of the model, the results and the generation of the necessary reports, including recommendations to be used by the aircraft design teams to enable them to avoid airframe natural frequencies close to the rotor head excitation frequencies. This role demanded very close coordination with the design teams to ensure that any design changes during the development of the FE models were fully reflected in those models to ensure accuracy of the results.
