A study of the effects of scaling on structural integrity assessment and feasibility of physical validation

For nuclear welded components the complex nature of the stresses involved means it is often advantageous to produce mock-ups in order that the structural integrity and performance may be assessed. The weight and size of these components can make the production of mock-ups prohibitively expensive and impractical, and so the use of scaled models is considered here. The scaling laws encountered affecting the applied loads, residual stresses and crack driving forces that are of interest are investigated using numerical analyses and finite element simulations. Of particular interest is the physical validation of these laws and the statistical difficulties that may be encountered.
The scaling of applied loads required to obtain the same residual stress fields and stress intensity factors are investigated using simulated four point bends. The statistical nature of fracture introduces uncertainty into fracture measurements which this paper takes into consideration in preparation for physical validation, ensuring that the random nature of fracture will not make the described laws impractical to validate.