Aeroelastic effects influence aircraft design at many points in the development process. These include static wing deformation, which is important for flight performance and handling characteristics, and questions regarding the effectiveness of control surfaces and vibration behaviour, as well as the aeroelastic stability limits with regard to divergence and flutter. In addition to this, one of the main tasks in aircraft development is the determination of the static and dynamic loads that act on the aircraft. Load analyses are used both for the dimensioning of components (wings, fuselage and other parts), as well as to demonstrate safety, for example, for certification (showing that maximum permissible loads are not exceeded). The work of the Institute in the field of loads and design is derived from these requirements.
The aeroelastic design and analysis process
The objective is to design an aircraft component (for example, a wing) with the best possible aeroelastic characteristics, or to evaluate an aircraft configuration with regard to its aeroelastic characteristics. In both of these fundamental tasks, the loads on the flexible structure must be considered.
For the creation of suitable simulation models, the process relies on global aircraft data, which is ideally provided by the remit. In particular, this includes the definition of the aircraft configuration and the transport task – for example, the size and configuration of the aircraft, specified take-off weight, number of passengers, additional load, range, flight speed, flight altitude. The applicable licencing regulations result from this data. In most cases, the Institute of Aeroelasticity deals with passenger aircraft according to CS-23 and CS-25, as well as light aircraft and military configurations, each with their own constraints. At the Institute, this process is also used for the design of wind tunnel models.