Organizations such as NASA and the US air force use the principles of fracture mechanics to ensure systems and missions exhibit a high degree of reliability and safety. Specifically, a fatigue crack growth analysis is required of fracture-critical parts, which if designed incorrectly, have the potential of failing catastrophically. The analysis is based on two assumptions: 1) All individual components of a system contain flaws or crack-like defects. 2) The use of non-destructive evaluation (NDE) techniques does not negate the above assumption. In other words, theoretic analysis must be performed in addition to NDE, which may be used to establish a probable upper bound for the initial crack size assumed.

Located near Phoenix, Arizona, Proof Engineering uses industry accepted tools such as NASGRO and AFGROW in conjunction with finite element software to perform fatigue crack analyses. These tools were initially developed by NASA and The Air Force Research Laboratory respectively with the goal of quickly performing damage tolerance life assessment studies of mission critical hardware. Their primary functions include:

• Calculation of fatigue crack growth life (FCG), critical crack size and stress intensity factors (K)

• Store, retrieve and curve fit FCG and fracture toughness data

•Calculate Ks and stresses using a 2-D boundary element method

Fracture mechanics is very useful when applied to any component or system that requires a high level of reliability in which catastrophic failure could lead to dire consequences such as: severe monetary setback, environmental catastrophes, loss of life, or mission failure. A few examples of applications include space vehicles, fighter jets, pressure vessels, offshore oil rigs, oil tankers, missiles, and UAVs. Additionally, any systems operating in cold environments, brittle components in general, or weldments may also be good candidates for fracture analysis.