ABSTRACT
Structural integrity is often relegated to the background, until something goes wrong. Traditional structural engineering codes do little to address the breadth and depth of considerations required to ensure long-term function of structures in moderately to severely aggressive environments. Oversimplification and ignoring past mistakes lead to things that matter being missed. Civil engineering history is punctuated by things we missed—and sometimes minimized—leading to unnecessary loss of life and property. Civil codes talk about a fatigue threshold in steels. Fatigue is time-dependent crack growth due to cyclic stresses. Two primary design methods of treating fatigue exist: safe life and fracture-mechanics correlations. A more effective fatigue design approach is to use fracture-mechanics correlations. Fracture toughness, like all structural properties, is influenced by size. Fracture is the separation of two materials that once were together. Fracture toughness is to the boxer as strength is to the weight lifter.
