Topology Optimization Of Load-carrying Board In Fuselage Low-Velocity Flutter Model

The design of any aircraft must experiment through a great deal of wind tunnel experiment then can complete the leap from ground to air. The wind tunnel experiment, according to the alike model, is one of the necessarily links in the process of the aircraft researches to manufacture.The body of an airplane model that used in the low-velocity flutter wind tunnel experiment, can be simplified into the load-carrying board and the grid structure that emulates the shape of the airplane. In the earlier design of load-carrying board , the traditional experiential design method is adopted, and load-carrying board is divided into zones of different thickness that is is symmetry in the core palte center. The traditional experience design method exists many problems such as excessively depending on the experience of designer, a long time of design cycle and wasting a great deal of manpower and material resources. The manufacturing processes of the designed structure is very difficult and the procedure is excessive. Therefore a new design method that can solve the problems above is needed.Topology optimization for frequencies of load-carrying board of an airplane model is studied by the method of bi-directional evolutionary structural optimization in this article, which is used to substitute the traditional experiential design, and appropriate ptimization structure is gained.First, topology optimization model of continuum structure with frequencies as object function and the volume as the constrained condition is established by the method of bi-directional evolutionary structural optimization. A kind of checkerboard pattern suppressing method, combined involving an filtration technique of sensitivity redistribution with contrived control is put forward. The principle of adding and removing elements is also discussed. Second, load-carrying board model is established with the finite element analysis software. The natural frequencies and volume of the structure are obtained after modal analysis, which provides the constriant and object for the topology optimization design. Then, combining modal analysis implemented through ANSYS with BESO for frequencies programed by MATLAB, topology optimization programe for plate is compiled. The program is used in the topology optimization of load-carrying board ,and appropriate ptimization structure is gained. At last, new strcture based on topology extraction is constructed,which indicates that the optimal design is efficient.