Benchmark analysis of fracture simulation for steel fiber reinforced concrete slab subjected to punching shear

The need for improved punching shear performance is constantly under review, particularly for slabs between stories or in indoor parking garages of collective buildings.As a part of this effort, the detailed finite element model for this slab was discussed.For the benchmark and parametric analysis of the failure tests conducted by fib, the overall punching shear load-vertical displacement relationship, local reinforcement strain, and concrete cracking pattern were investigated through a nonlinear finite element model.A square slab with a length of 2,550 mm and a thickness of 180 mm is modeled with a three-dimensional solid element incorporated with conventional rebars and hooked-end steel fiber inclusions.The two-step mechanical homogenization was conducted in order to extract the effective properties of this fiber reinforced concrete composites.Damaged plasticity was applied for the concrete nonlinearity.The punching shear load was applied to the central part of the slab in the vertical upward direction, until the radial cracks occured to failure in the simulation.In order to develop a possible ductility guarantee for the punching shear condition with relatively high uncertainty, the shear resistance performance of a steel fiber reinforced concrete slab was discussed in accordance to arbitrary fiber directions and different fiber aspect ratios.