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.

本文介绍了冲击载荷的几何形状（落锤重量）在损伤状态下对矩形空心截面（RHS）钢梁的弱轴在冲击载荷下的影响的实验和数值研究。为此，在两个不同高度的落锤重量分别为1400 mm和2000 mm的情况下，测试了六个长度为2000 mm的简单支撑钢梁样本的弱轴。落锤的头部几何形状由三种不同的类型组成，即矩形（SPC＃R），圆形（SPC＃C）和三角形（SPC＃T），而冲击器的重量在所有条件下均保持恒定。为了对钢梁上的冲击载荷进行数值模拟，首先，使用Abaqus Explicit包装程序分析了冲击载荷下样品的三维有限元模型。为了确定落锤几何形状的影响，已经比较考虑了五个参数，即位移，加速度，反作用力，应力分布和塑性应变。对位移，加速度和反作用力进行了实验和数值比较，而应力分布和塑性应变仅在经过验证的有限元模型上进行了数值比较。在数值研究的第二部分中，研究了撞击器的几何形状对方形空心截面（SHS）梁的影响。为此，从两个不同的落锤高度分别为1400 mm和2000 mm的高度分析了六个长度为2000 mm的简单支撑钢梁的有限元模型。所获得的结果表明，在两种类型的截面中，均被三角型冲击器撞击的梁出现了最大的挠度和加速度。此外，在使用三角头冲击器的测试中，观察到最大的塑性变形和应力分布。在使用矩形冲击器的测试中，发生的损坏和位移最小。综上所述，对于恒定的冲击载荷，与圆形和矩形冲击头相比，冲击头的三角形头部对钢梁造成更大的破坏和塑性变形。在使用矩形冲击器的测试中，发生的损坏和位移最小。综上所述，对于恒定的冲击载荷，与圆形和矩形冲击头相比，冲击头的三角形头部对钢梁造成更大的破坏和塑性变形。在使用矩形冲击器的测试中，发生的损坏和位移最小。综上所述，对于恒定的冲击载荷，与圆形和矩形冲击头相比，冲击头的三角形头部对钢梁造成更大的破坏和塑性变形。