the points on the upper flange. It is concluded that the dynamic response of the symmetrical position is similar.The normalised velocity level spectra of the bare steel beam excited by the vertical force at the upper flange centre are shown in Fig. 8. The vibration of the web and flanges is much smaller than that of the web excitation as the vertical stiffness of the beam is larger than the lateral stiffness. Nevertheless, the velocity level of the beam excited at the upper flange centre has a wider dominant frequency range.The normalised sound pressure level (SPL) spectra at three typical points emitting by the bare steel beam excited respectively by the horizontal force and vertical force are shown in Fig. 9. It is found that the SPLs under the horizontal excitation at the web centre are also much larger than those under the vertical excitation at the upper flange. So the test data under the horizontal excitation at the web centre are selected to analyse the vibration and noise