15.04: Parametric study on steel beams with fin‐plate joints under falling floor impact

Abstract

ABSTRACTDuring the past decade, many quasi‐static tests were conducted on structures against progressive collapse. As a typical testing method, middle‐column‐removal scenario was used in most studies. It should be noted that another important scenario, i.e. falling floor impact, may also cause progressive collapse. In this paper, a series of numerical analyses was carried out to study the dynamic behaviour of steel beams subjected to falling floor impact. Fin plate connections were used to connect the beam and the columns. 3‐D finite element models (FEM) were established by ANSYS/LS‐DYNA and validated against experimental data. Good consistency was shown between experimental tests and numerical analyses. By using the validated finite element models, four parameters including strength of material, impact load, impact location and inertia effect were studied. High strength materials were beneficial to enhance the impact resistance in the falling floor impact scenario. Higher impact velocity can slightly improve the capacity of energy dissipation. For location of falling impact, it was more critical if the hammer dropped onto the joint region compared to the mid‐span region. The inertial effect should be considered in the impact analyses because it significantly decreased the maximum vertical displacement of specimens.