Structural dynamic modification

Vibration and acoustic requirements are becoming increasingly important in the design of mechanical structures, but they are not usually of primary concern in the design process. So the need to vary the structural behaviour to solve noise and vibration problems often occurs at the prototype stage, giving rise to the so-called structural modification problem. In this paper, the direct problem of determining the new response of a system, after some modifications are introduced into the system, is analysed using two different databases: the modal database and the frequency response function database. The limitations of the modal database are discussed. Structural modifications that can be accounted for are lumped masses, springs, dampers and dynamic absorbers.