Analysis of lattice steel columns under lateral continuous twice-impact

Lattice columns are often used as the main load-bearing components in engineering structures, and are inevitably impacted by other unintentional loads under engineering service environments, and the evaluation of the protective performance and optimization of the design of the building structure under impact loading is a key issue of concern in the fields of national defense, civil engineering, and other military and civilian use. In this paper, 1:2 scaled-down secondary impact experiments were carried out on lattice columns along different impact directions with the same impact energy each time, and compared with single-impact lattice columns under the same total energy, to analyze the force and deformation characteristics of the lattice columns under the impact loads. Subsequently, based on the experimentally verified finite element model, a continuous secondary impact simulation was carried out on the foot-foot lattice column, and the results of the dynamic response of the lattice column subjected to two consecutive impacts with the same total energy were obtained, and the effects of different energy distribution on the impact force, residual displacement and residual kinetic energy were analyzed. The results show that under the same total energy, the displacement of lattice columns under a single impact is larger than that of a secondary impact. The optimal energy distribution obtained by numerical simulation can reduce the residual displacement of members impacted along different directions by about 12%; when the lattice column is subjected to a larger proportion of energy for the first time or a smaller proportion of impact energy for the second time, the total energy absorbed by the column is smaller. The results of the study can provide a reference for the design method of lattice steel columns under such loading conditions.