Analysis of Helical Stair Slab using ANSYS

Staircase is used in buildings for providing access to pedestrian to different floors and roof of a structure. A Stair is a series of steps with or without landings or platforms, which is installed between two or more floors of a building to bridge a large vertical distance. These are designed as slab supported on the beams or walls or frame structure at edges of landings. The design is generally based on the guidelines by different codes of practices. No special treatment is given for varying support conditions and shape of the stair slab. The behavior of helical stair slab has been very difficult to be understood due to its geometry. Individual attempts have been made by researchers to get an idea of approximate behavior of its geometry under different circumstances. The real behavior of the stair slab may be obtained by making a prototype and testing it by applying various loads at different points. In this work we have analyzed helical stair slabs of different radii by modeling it in ANSYS. Three stair slabs of different radii ranging from outer radius 4.0 to 4.8 have been modeled and loads have been applied to get an idea of deflection and stresses produced. Stress and deflection contours have also been obtained. Graphs have been made for deflection and compared for the stair slabs of smaller and bigger radii.