Viscoelastic layer installed on the

Viscoelastic layer installed on the web can achieve more reduction of vibration and noise of the beam than the same patches on the flanges when the beam is excited at the web centre horizontally according to the previous study. The data of velocity and sound pressure of the steel beam damped by CLD configurations with various thicknesses are analysed to assess the thickness effect on the mitigation of the vibration and noise of the beam.5.2.1 Vibration MitigationWhen the beam is excited at the web centre by the horizontal force, the measured waveforms of the normalised velocity at V2– 4 are shown in Fig. 17. The root mean square values under Case 1 and 3 – 6 are 2.8 mm/s, 1.7 mm/s, 1.4 mm/s, 0.7 mm/s and 0.6 mm/s respectively, indicating that the vibration of the steel beam can be reduced considerably by CLD. Particularly the velocities of the beam under Case 5 (1.0 mm thick damping layer