Characteristics of local vibration in I-section steel beam subjected to lateral impact load

Experimental and numerical methods were used to study the characteristics of local vibration in a thin-walled steel beam under impact load. The experiment was performed with a simple supported I-section beam subjected to a light lateral impact. The impact load was applied through an impact hammer to the upper flange at the midspan of the beam. The forces and the vibration accelerations normal to the in-plane direction of each plate element of certain cross sections over the beam were measured. Numerical analysis of the beam was carried out by means of the finite strip method. The elastic vibration accelerations were calculated by applying the measured value of the impact loads to the force. A comparison was made between the experimental results and the analytical results in terms of the acceleration-time profiles, their frequency spectra and the vibration mode shapes. Consequently, the characteristics of local vibration in the thin-walled steel beam caused by the lateral impact load were clarified. It was found that the calculated acceleration-time profiles in the initial impact process were in good agreement with the measured ones.