ABSTRACT
Design of structural elements can be carried out by permissible stress or ultimate limit state (ULS). Permissible stress limits the loading to a predetermined safe working stress, commonly known as elastic design as deformation of the element is recoverable (elastic). ULS factors the loads (partial safety factors) to be carried and the design is related to the potential ultimate failure of the structural element. Defl ection of the structural element is limited to the elastic deformation of the material and the effect on what is being carried. There are different defl ection limits for different materials.
