Effect of weld in crack growth of structural steel members

The fracture behaviour of cantilever beam components subjected to transverse bending loads are studied using energy balance concepts. Effect of initial crack in the parent metal and weld metal portion is investigated and strain energy release rates are reported. Theoretical expressions to determine the strain energy release rates and stress intensity factors are derived for beam components with initial cracks at fixed end and the geometry factors are determined from experiments so that the results are directly useful to the designer. Tests with mild steel specimens with and without weld indicate that weld shows more strain energy release when crack grows to the same amount. In this study a test procedure to evaluate the significance of defects under plane stress conditions is suggested.