Finite element analysis of interior slab-column connections strengthened by steel angle plates

摘要

This paper is concerned with the finite element modeling of strengthened interior slab-column connections in the existing continuous flat slab structural system by employing steel angle plates at the slab-column junctions and fastened by shear bolts. This technique utilizes the advantage of combined action between the angle plates and bolts in resisting shear particularly at the slab-column edges. Three-dimensional analysis was carried out on such slabs employing concrete damaged plasticity model in ABAQUS to investigate their performance in terms of punching shear resistance, load-displacement response, and crack pattern at failure. The numerical models were first validated against the experimental results reported by other researchers. The proposed strengthening technique results in a substantial increase of load-carrying capacity ranging from about 59 to 79% compared to the unstrengthened slab, and has also provided better stiffness, ductility and energy absorption in the slab system that change the mode of failure from a pure punching shear to flexural failure. The finite element results are compared with the calculated values according to provisions in the current design codes for evaluation purposes. A simple but reliable approach which is based on yield line theory to estimate the flexural capacity of the strengthened slabs is also outlined in this paper.