Jakob C. Bruhl

Missile Impact on SC Walls: Global Response

Steel plated composite concrete (SC) 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 singledegree-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.

Impact Assessment of SC Walls Using Idealized SDOF and TDOF Models

Steel-plate composite (SC) walls have been used recently in overseas and domestic nuclear power plant (NPP) projects. For safety-related NPP facilities, these walls may be required to resist the effects of impact. Analysis of the structural global response of conventional reinforced concrete (RC) walls to impact loadings, such as those from tornado borne missiles or turbine-generated missiles and secondary wall impacts due to heavy load drops, is reasonably approximated using simplified dynamic analysis methods. For cases in which global bending dominates the response, an inelastic single-degree-of-freedom (SDOF) model is effective. For some impact loadings, the response includes considerable localized deformation. Analysis for these cases requires a cascaded two-degree-of-freedom (TDOF) model with one mass and resistance representing the global flexural response and a second mass, resistance and damping representing the local deformation response. In this paper, the methodology to complete dynamic analysis of impact loadings on SC walls (both SDOF and TDOF models) is provided, and SDOF and TDOF model results are compared to SC wall dynamic response from nonlinear finite element models.

Preliminary Study of Blast Response of Steel-Plate Reinforced Concrete Walls

Steel plate-reinforced concrete (SC) structures are ideal for protective construction. Tests have demonstrated improved resistance to projectile perforation and construction benefits when compared to conventional reinforced concrete (RC). By placing the reinforcing steel at the extreme fiber of the section, SC walls have higher strength and stiffness than an RC wall of the same depth and reinforcement ratio. This paper presents results from a preliminary analytical study of the blast response of SC structural members. The focus of this study is on one-way slabs subjected to uniform blast loads as are common for far-field explosions. Design parameters for blast protective design of SC walls are explained and necessary modifications to existing RC blast resistant design methods to account for SC behavior are recommended.

Experimental Resistance and Available Ductility of Steel-Plate Composite Walls in One-Way Bending

AbstractThis paper presents the results of an experimental program in which eight one-third-scale steel-plate composite (SC) wall sections were tested in four-point bending to ultimate failure (ten...