where σ is the applied stress, a is the crack length, and π is a constant.
The team used the following equation to calculate the stress intensity factor: principles of fracture mechanics rj sanford pdf pdf work
The team integrated this equation over the number of pressure cycles to estimate the final crack length: where σ is the applied stress, a is
KIC = σ√(πac)
where Y is a geometric factor that depends on the crack configuration and the component geometry. The team also discovered that the pipeline had
where da/dN is the crack growth rate, C and m are material constants, and ΔK is the stress intensity factor range.
The team also discovered that the pipeline had been subjected to a series of pressure cycles, with pressures ranging from 500 to 900 psi. These cycles had caused fatigue cracks to form and grow in the weld region.