LOCAL FAILURE MODES OF SC WALLS SUBJECTED TO IMPACTIVE LOADING
24th Conference on Structural Mechanics in Reactor Technology
Steel-plate composite (SC) walls are gaining momentum as an innovative system for design and construction of safety-related nuclear facilities due to their modularity and resistance to impactive and impulsive loading. Impactive design focuses on preventing perforation of the wall by the impacting missile. Once perforation has been prevented (through design), other local damage states such as punching shear failure, excessive deflection, and steel faceplate rupture need to be considered. Current approaches use single or two degree-of-freedom (SDOF or TDOF) models along with a static resistance function to estimate the maximum deflection and ductility demand on the wall if missile perforation is prevented. This paper focuses on numerically developing the static resistance function for SC walls, while simultaneously considering the ductility associated with local failure modes such as punching shear failure, flexural yielding followed by shear failure, and plastic mechanism formation. The paper details the development of 3D nonlinear finite element models of SC walls subjected to concentrated loading up to and beyond failure. The models account for various complexities of behavior including steel plate yielding and fracture, tie bar yielding and fracture, concrete cracking and crushing, and stud anchor slip capacity. The paper shows that for a given faceplate reinforcement ratio (4.3%), the local failure mode changes from punching shear failure to flexural yielding (followed by shear failure) to plastic mechanism formation as the tie bar (shear) reinforcement ratio increases (0.18 - 0.85%). The transitions in the local failure modes depend on the plastic strain demands and capacities in the components of the SC wall, namely, the steel plate, tie bar, and stud anchor. The paper identifies the future research path, and how the results can be used to design the preferred hierarchy of local failure modes.
Conference presentations, papers, posters
Steel-plate composite (SC) walls
Amit Varma, Joo Min Kim, Jungil Seo, and Jakob Bruhl. "LOCAL FAILURE MODES OF SC WALLS SUBJECTED TO IMPACTIVE LOADING". 24th Conference on Structural Mechanics in Reactor Technology, 2017.