The third option in the performance on the vibrating systems is the addition of rigidity, trying not to increase the mass of the system. The detail of the increase of rigidity is that one has to consider that the frequencies of resonance of the system will increase, although the amplitude of the vibration will be smaller.
It is often also possible to try to include damping functions to these stiff systems.
Within the stiffening materials of the structure we can discard the use of crossbeams or beams. For example in the roof panels of the vehicles.
A strategy to increase the rigidity with small increase of mass is the use of multilayer material, in which a fibre layer has the function of resisting loads in tension-compression while other light layers have the function to give inertia to the material. A specific case is the structures of the honey comb.