Allowable Stress Design
Allowable stresses design (ASD) or working stress design is traditional method of analysing structures. This design approach has been used for a long time. The basic idea of this method is to keep the applied stress within a structure below a maximum allowable stress which is calculated in relation to the elastic limit of the structures material of construction.
The civil engineering discipline has largely left allowable stress design (ASD) behind and has moved onto limit state design (LSD). Mechanical structures are still largely designed using ASD but there is some movement towards the LSD method.