Sizing Welds Taking into Account the Direction of Loading

The traditional approach of assuming that the throat of the fillet weld resists the load, regardless of the direction of loading is followed in Indian steel code IS 800. However, based on experimental research, the American Structural Welding Code-Steel, the American Institute of Steel Construction code, and the Canadian code have modified the equations to consider the direction of loading. These provisions are discussed, and three examples are also included to show that economic design of weld material can be achieved by using these provisions. Although the end fillet may resist more loads, it may have less ductility than the side fillet. Hence, the designer should exercise caution while using the end fillet, especially when ductility is required in situations where overloading is likely to occur.