Stress intensity range (ΔK)
Definition
The difference between the maximum and minimum stress intensity factor in one loading cycle, ΔK = K_max - K_min. The Paris law describes crack growth rate da/dN as proportional to ΔK to a power m, typically 2 to 4 for structural metals.
Related terms
- Beach marks
- Macroscopic curved bands on a fatigue fracture surface, visible without magnification, produced by changes in crack growth rate during service (load changes,...
- Fatigue fracture
- Fracture resulting from repeated cyclic loading, typically at stresses below the static yield strength. The fracture surface has characteristic markings (beach marks,...
- Fatigue striations
- Microscopic parallel marks on a fatigue fracture surface, formed during individual loading cycles in Stage II crack growth. Visible by SEM at...
- Multi-site damage (MSD)
- The simultaneous presence of fatigue cracks at multiple adjacent fastener holes or structural features, characteristic of ageing aircraft fuselage and other riveted...
- Ratchet marks
- Radial steps or ridges on a fatigue fracture surface separating adjacent regions that initiated from separate sites. They run from the component...
Explained in
- Fatigue Fracture: Beach Marks and StriationsThe difference between the maximum and minimum stress intensity factor in one loading cycle, ΔK = K_max - K_min. The Paris law describes crack growth rate da/d...