Abstract:

The vibration characteristics of plastic fuel tanks during the actual vehicle operation were measured in a test bench designed with modal analyses for a light-weight vehicle designing. The vibration modal of the fuel tank were compared and analyzed by using a hammering method for dry mode and the wet mode with different water contents under free suspension state and installation state. The test bench has sufficient rigidity to ensure measure the vibration characteristics of the fuel tank in the frequency band of interest, and to regenerate the constraints to the fuel tank in a actual running vehicle. The influence of boundary conditions on fuel tank vibration characteristics was analyzed with the norms of frequency response function, modal frequency and vibration mode, modal phase collinearity (MPC) and mean phase deviation (MPD). And the influence of the liquid filling amount on the modal frequency and vibration mode of the fuel tank in the installed state was focused on analysis. The research results show that as the water filling increases, the natural frequency of the fuel tank decreases with a changing vibration mode.

Key words: light-weight vehicle materials , fuel tank ,  constraint condition ,  vibration tests ,  modal analyses