Missile Impact on SC Walls: Global Response

Steel-plated composite (SC) concrete walls, which consist of a poured concrete core between two studded steel plates, have been utilized in many applications in lieu of conventional reinforced concrete (RC) walls. For this type of wall, the steel reinforcing plates serve as formwork, which allows for modularization of the design and correspondingly accelerated construction. Recently, both overseas and domestic nuclear power plant (NPP) projects have incorporated SC walls into their designs. When installed in nuclear plant facilities, such walls may be required to resist the effects of extreme loadings such as tornado missile and aircraft impact. The analysis of the structural response of conventional RC walls to such extreme loadings is well understood and is amenable to a simplified and well known inelastic single-degree-of-freedom (SDOF) approach which treats the wall as an effective mass with an easily defined inelastic spring. The purpose of this investigation is to study the SC wall load deformation behavior or resistance function, under missile impact, for input to an SDOF model. Based on pseudo-static nonlinear finite element analyses, the SC wall load deformation behavior under a central concentrated load is investigated for some typical wall panel configurations. System parameters are varied to assess their effects on the resistance function.