A NEW DASSAULT INDUSTRIAL APPROACH FOR AERO-STRUCTURAL OPTIMIZATION OF COMPOSITE STRUCTURES WITH STACKING TABLE CONSTRAINTS

摘要

During the initial design phase the evaluation of the aircraft's structural mass for various plan forms is still a challenge, even more so when using composite materials. The structural mass results from all the structural parts which insure both the structural integrity as well as the static and dynamic stability of the aircraft. In order to increase aircraft performance this mass should be minimized. The aero-structural optimization performs this minimization while respecting the constraints on the structure: sustain loads and satisfy various aeroelastic constraints. These constraints could be avoiding flutter phenomena in the flight envelope or guarantying static aeroelastic characteristics such as aileron efficiency. With a composite structure numerous technological constraints are also required to ensure the final structure will respect state of the art drawing rules and can be easily manufactured. One important technological constraint for a composite structure is to use a single stacking table. These new constraints introduce many new complexities in the optimization process. This paper describes an industrial method developed at Dassault Aviation to perform this aero-structural optimization on composite structures. This fully automatic process can compute the optimized structural weights of several configurations. The resulting structure uses a unique stacking table that is optimized by the process, thereby ensuring the structural mass is minimal. Combining this with aerodynamic performance data for each configuration, it becomes a powerful tool to drive the design of new aircraft. First the global optimization process will be briefly presented. Then the method used for optimizing a composite structure with a stacking constraint will be described. Finally an application of this process on a generic Falcon jet with a composite wing will be shown.