Otimização de amortecedores de massa sintonizados no controle de vibrações em vigas e placas

Abstract

The possibility to deal with more resistant materials allows the design of leaner and lighter structures which may be more sensitive to the action of dynamic loads that arising from the movement of people, machines or actions of nature, such as wind. The propagation of cracks, additional stress due to excessive displacements as well as discomfort to users due to the accelerations that arise in the structure are some of the structural problems involving the dynamics. Other adversity is related to sensitive equipment installed in floors, in which, when subjected to certain (undue) acceleration can suffer damages. The most commonly used approaches to control these excessive vibrations are the stiffening of the structure, but in many cases this type of approach is made unfeasible by architectural, aesthetic restrictions or relative to the structure's own ability to undergo the addition of heavy structural elements to the stiffening. Vibration problems on slabs are not uncommon; industrial slabs, for example, are subject to various types of simultaneous dynamic actions from the various machines in operation installed on the factory floor. Another case is the slabs of academies, party halls and other environments with large movement of people that generate accelerations in the floor. The present work explores the adoption of mechanical vibration control systems (attenuators) coupled to the structures, specifically in beams and plates, as an alternative solution of the engineering problem. Optimization techniques are used to obtain projects with the best cost-benefit ratio of attenuators. In this way, a numerical modeling is performed via computational implementations of the vibration problem and its control in beams and plates, the results are validated and compared with literature samples. It is noted that with the optimization process it is possible to arrive at the same structural response using lower values for mass and damper ratio parameters for TMD.