Abstract: This study is concerned with the optimization of the finite element dynamic model of large structures. The objective value is the natural frequency measured by vibration tests.Based on the dynamic balance equation and orthogonality, the method of combinatorial elements is used to make the agreement of the computational natural frequency with the tested natural frequency by modifying the elements of the mass matrix. The method has been successfully applied in the tailplane of an unmanned aircraft.

Key words: optimization, large structure, finite element method