Experimental and numerical analysis of impactor geometric shape effects on steel beams under impact loading

This paper presents experimental and numerical studies about the effect of geometric shape of impactors (drop weight) at damage status on weak axis of rectangular hollow section (RHS) steel beams under impact loadings. To do so, six simply supported steel beam specimen with 2000 mm length have been tested on their weak axis from two different height of the drop weight as 1400 mm and 2000 mm respectively. The head geometry of the drop weight consisted of three different types namely rectangular (SPC#R), circular (SPC#C) and triangular (SPC#T), while the weight of the impactors was kept constant in all conditions. For numerical simulation of impact loading on steel beams, initially, three dimensional finite element models of the samples under impact loading were analyzed using Abaqus Explicit package program. To determine the effect of geometric shape of drop weight, five parameters namely displacement, acceleration, reaction forces, stress distribution and plastic strain have been considered comparatively. Displacement, acceleration and reaction forces were compared experimentally and numerically while, stress distribution and plastic strains were only compared numerically on verified finite element models. In the second part of the numerical study, the effect of geometric shape of impactors on square hollow section (SHS) beam was investigated. For this purpose, six simply supported steel beams' FE models with 2000 mm length have been analyzed from two different height of the drop weight as 1400 mm and 2000 mm respectively. Obtained results show that the maximum deflections and acceleration have been occurred in the beams that were hit by the triangular headed impactor in both types of the section. In addition, the biggest plastic deformation and stress distribution have been observed in the tests where triangular headed impactors were used. The minimum damage and displacement have been occurred in the tests where rectangular shaped impactor have been used. To sum up, for a constant impact load, triangular head of impactor inflicts a bigger damage and plastic deformation on steel beam in comparison to circular and rectangular heads of impactors.