Can Ants Design Mechanical Engineering Systems?

The present contribution deals with the optimal tuning of a vibrating blade dynamic vibration absorber by using ant colony optimization (ACO). Dynamic vibration absorbers (DVAs) are systems constituted by mass, spring and damping elements, which are coupled to a mechanical system to provide vibration attenuation. The main idea behind the DVAs is the generation of a force that has the same intensity as the excitation force but in the opposite phase. This phenomenon is known as anti-resonance. The tuning of the DVA is the procedure that sets the anti-resonance frequency to a given value by adjusting the DVA parameters. Based on this theory, the optimization problem is described as the minimization of the objective function that relates the difference between the resonance frequencies of the primary system and those of the DVA. To solve the optimization problem, ACO techniques were used. In the early nineties, when the ant colony algorithm was first proposed, it was used as an approach for the solution of combinatorial optimization problems, such as the traveling salesman problem. However, the extension for operating with continuous variables is recent and is still being developed. In this context, this paper presents an engineering application for a continuous domain problem. Numerical results are reported, illustrating the success of using the methodology presented, as applied to mechanical systems.