Abstract: The influence of cross wind on the deformation and vibration characteristics of the boom of the ladder fire truck is explored, finite element software was used to study the structural vibration law of ultra?high ladder boom under different wind speed conditions. The wind load deformation of the boom is mainly reflected in the swing of the auxiliary arm under the action of wind load, and the bending deformation caused by eccentric moment is mainly used. Under the combined action of external load and periodic internal stress, the boom produces a low?frequency source that excites the low?order mode of the boom. The deformation of the boom of the raised fire truck shows the characteristics of periodic vibration, and the vibration amplitude gradually increases with the increase of wind speed. Based on the research results, this paper proposes a solution that can provide ideas for the design of improved ladder fire trucks.

Key words: ladder fire truck, boom, finite element analysis, cross wind, vibration